What is Bell’s Palsy?

Bell’s palsy involves dysfunction of a nerve that controls facial muscles, resulting in weakness or paralysis of one side, or more rarely both sides, of the face.

The majority of people with Bell’s palsy begin to recover without treatment within two to three weeks, achieving full recovery within three or four months, but recovery can take longer in some people; permanent loss of function is rare.

What are the Signs and Symptoms of Bell’s Palsy?

• One-sided facial paralysis that occurs over a few hours to a few days. This includes a droop to the mouth on the affected side and an inability to frown, close the eye, or produce tears.
• This can cause the cornea to become dried out which could lead to long-term visual impairment.
• In the large majority of cases, symptoms resolve completely within nine months.
• People who do not have some recovery within 21 days have a greater risk of lasting facial muscle weakness.

It is important to note that symptoms of Bell’s palsy often overlap with those of stroke. For this reason, it is imperative that medical attention be sought as soon as symptoms of facial weakness or paralysis are perceived.

How is Bell’s Palsy Treated?

• A short course of corticosteroids is recommended within three days of symptom onset to reduce inflammation. Corticosteroids have been shown to improve outcomes and recovery at six to 12 months.
• Antiviral therapy is generally only recommended in severe cases.
• Artificial tears and ophthalmic ointments can be used to prevent damage to the cornea.

Top Nutrients for Bell’s Palsy

• Methylcobalamin. Methylcobalamin plus a corticosteroid helped patients recover faster than a corticosteroid alone in a study of subjects who had Bell’s palsy longer than two weeks.
• Acetyl-L-carnitine. A study of subjects with facial palsy found supplementing with acetyl-L-carnitine along with methylprednisolone reduced a measure of paralysis by half, whereas it remained the same with methylprednisolone alone.
• Omega-3 fatty acids. Omega-3 fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are converted into anti-inflammatory compounds that can help protect nerves from damage.
• Niacin. In a series of 74 cases treated with 100‒250 mg of niacin, 73 cases resulted in good facial nerve response within 2‒4 weeks.
• Anti-viral interventions. Natural agents shown to combat viral infection, including licorice, zinc, lysine, and reishi mushrooms, may be of some benefit for those affected by Bell’s palsy.

“Bell’s palsy” typically refers to acute facial paralysis of unknown origin.¹ It results from dysfunction of a nerve that controls the facial muscles, tear glands, and certain salivary gands.^1-3 First anatomically identified by Sir Charles Bell in 1821, Bell’s palsy causes weakness or paralysis of one side or, more rarely, both sides of the face.⁴ Bell’s palsy often manifests rapidly, such that those affected may rise from bed in the morning with inexplicable one-sided facial weakness or paralysis and fear they have experienced a stroke.⁵

Bell’s palsy is the most common disorder affecting the facial nerve and cause of facial paralysis, with more than 40,000 cases diagnosed each year in the United States.⁶ Bell’s palsy can occur at almost any age and is equally common in men and women. People with diabetes appear to be at increased risk, and the risk is increased 3-fold during pregnancy, especially in the third trimester and first week postpartum.^1,7

The underlying cause of Bell’s palsy is not known in most cases, but inflammation and reactivation of a dormant viral infection affecting the facial nerve, also called the cranial nerve VII, appear to be important contributing factors. Herpes viruses, specifically herpes simplex virus type 1 and herpes zoster virus, which causes chickenpox, are thought to be involved in a substantial proportion of cases.^1,2

Most people with Bell’s palsy begin to recover spontaneously within several weeks, achieving full recovery within nine months.^8,9 About 70% of the patients completely recover their facial muscle function, even without treatment; however, in about 30% of cases, long-term problems such as facial weakness, involuntary facial movements, or persistent secretion of tears may arise.²

Doctors may use corticosteroids to treat Bell’s palsy as they are helpful in reducing inflammation of the facial nerve and may shorten symptom duration if initiated soon after onset. The rates of complete recovery increase with early use of a corticosteroid.^10,11 Antiviral drugs such as valacyclovir (Valtrex) or acyclovir (Zovirax) are sometimes used for the condition. However, some studies suggest antiviral drugs do not provide significant benefits when used alone or together with steroids. Therefore, if there is a benefit with antiviral drugs, the benefit is likely modest at best.¹²

Given the potential role of inflammation in Bell’s palsy, nutrients that help manage the inflammatory response, such as curcumin and omega-3 fatty acids, may support recovery. In addition, nutrients that support healthy nerve cell function such as vitamin B12, acetyl-L-carnitine, and ginkgo may benefit those with Bell’s palsy. Nutrients that inhibit herpes viruses, such as reishi mushroom, licorice, zinc, and L-lysine, may also be supportive.^6,13-30

In this protocol, you will learn about the biology of Bell’s palsy and its possible triggers. You will also learn how to recognize the signs and symptoms of this condition, and how it is diagnosed and treated. Finally, you will learn about novel and emerging therapies as well as nutrients that may help speed recovery and reduce symptom severity.

Bell’s palsy has historically been considered an idiopathic condition (ie, a condition that arises spontaneously without a known cause). There are several theories regarding underlying mechanisms.

The most consistent underlying feature of Bell’s palsy is acute inflammation or edema of the facial nerve.^8,12,31 The facial nerve passes through small canals in the skull along its path to the facial muscles. When a dormant virus (generally assumed to be a herpes simplex virus) is reactivated and migrates to the facial nerve, an inflammatory response ensues leading to swelling and compression of the nerve within these small bony passages. Non-infectious factors, such as autoimmune processes, may also cause inflammation of the facial nerve and contribute to Bell’s palsy.^2,32-35

Inflammation and anatomical factors can result in blood vessel compression and ischemia (decreased blood flow and poor oxygenation) of the facial nerve. Ischemia, which can cause thickening of connective tissue and further nerve compression, has been proposed to be a factor in cases of Bell’s palsy that do not resolve.^8,36

It is widely thought that reactivation of latent viral infection triggers the onset of Bell’s palsy in many cases.⁶ Herpes simplex virus-type 1 (HSV-1) is the most studied with regard to its relationship with Bell’s palsy.⁸ HSV-1 and other herpes viruses generally manifest in two distinct stages: during the first stage, there is active symptomatic infection and viral replication, whereas during the second stage, the virus is dormant (or latent), residing in the nervous system.^37,38 The dormant virus may become reactivated and give rise to another active infection.³⁹ Although some evidence suggests Bell’s palsy may be a manifestation of a reactivated herpes virus, such as HSV-1 or herpes zoster virus (also called varicella zoster virus, the cause of chickenpox and shingles), studies have not been able to consistently link the presence of either of these viruses with a majority of Bell’s palsy patients.^40,41 Moreover, Bell’s palsy is not typically associated with other classic signs and symptoms of herpes viruses such as lesions, itching, and pain.

Borrelia burgdorferi , the bacteria that causes Lyme disease, is an important possible cause of facial nerve palsy.⁴² Other infectious viruses have also been suggested as triggers, including adenovirus, Coxsackievirus, cytomegalovirus, Epstein-Barr virus, mumps, and rubella.⁴³

Another possible underlying mechanism involves an autoimmune process in which immune cells become activated against the myelin proteins specific to the facial nerve. This type of immune reaction may be triggered by an infection or, in rare cases, certain vaccines.^9,47-49

Bell’s palsy can occur at any age, but it most commonly affects people between ages 15 and 45.⁶ Although Bell’s palsy appears to affect men and women at similar rates, young women were found to be at greater risk of recurrent Bell’s palsy in one small study.⁶³ Evidence suggests Bell’s palsy may run in some families, and at least one genetic variant has been identified as a possible risk factor.^1,64

Several other conditions have been reported to have associations with Bell’s palsy, although the mechanisms behind these relationships is unclear.

• Infection. Recent viral infections, such as due to herpes viruses or respiratory viruses, have been linked to Bell’s palsy risk.^5,65-67 In addition, Mycoplasma pneumoniae has been found more frequently in those diagnosed with Bell’s palsy.⁶⁸ Bell’s palsy can also be a symptom of Lyme disease.⁶⁹ In one study, 14.7% of Bell’s palsy patients without a known cause had confirmed infection with the bacteria that causes Lyme disease.⁶⁰
• Pregnancy. The risk of Bell’s palsy increases 2- to 4-fold during late pregnancy and the postpartum period, and increased nerve compression is thought to be a contributing factor.^70-72 Bell’s palsy has been noted to be more common in women with other pregnancy complications, such as high blood pressure and preeclampsia, and may be an indicator of further pregnancy-related problems.^73,74 Women who develop Bell’s palsy during or just after pregnancy are more likely to have severe symptoms, less likely to receive timely treatment with corticosteroids, and have poorer outcomes than non-pregnant Bell’s palsy patients.^70,75
• Stroke. One study found individuals who experienced Bell’s palsy had a 2-fold increase in stroke risk during 2.9 years of monitoring compared with those who had not had Bell’s palsy. Treatment of Bell’s palsy with corticosteroids was found to mitigate the increase in stroke risk somewhat, but those who received corticosteroids still had a 67% increased stroke risk.⁷⁶
• Anxiety. Anxiety and Bell’s palsy share certain risk factors and may be interrelated. In one study, anxiety patients were found to have a 53% increased risk of developing Bell’s palsy, and Bell’s palsy patients were found to have a 59% increased risk of developing an anxiety disorder.⁷⁷
• Diabetes. Diabetes increases the risk of developing Bell’s palsy and is present in 5‒10% of people with Bell’s palsy.^1,2 In addition, the presence of diabetes has been correlated with a decreased rate of recovery from Bell’s palsy.^78,79
• Hypertension. High blood pressure has been associated with an increased risk of, and poorer recovery from, Bell’s palsy.^79,80 Individuals whose high blood pressure was well controlled were found in one study to have a better prognosis than those with uncontrolled hypertension.⁷⁸
• Obesity. Obesity has been linked to an increased risk of Bell’s palsy and has been associated with a poorer recovery rate.^81,82
• Metabolic syndrome. Hypertension, abdominal obesity, and high blood sugar are hallmarks of metabolic syndrome and are associated with increased risk of Bell’s palsy. Two other components of metabolic syndrome, high triglyceride and low high-density lipoprotein (HDL) cholesterol levels, have also been correlated with greater odds of developing Bell’s palsy, and Bell’s palsy patients with metabolic syndrome were found to have a lower rate of recovery.⁷⁹
• Migraine. Migraine sufferers in general have a slightly increased risk of Bell’s palsy. However, among adults between 30 and 60 years old, migraine patients were found to have a 28% increased risk of Bell’s palsy.⁸³
• Cancer. In one study, the risk of being diagnosed with cancer, especially oral cancer, was 43% higher during the five years following a Bell’s palsy diagnosis.⁸⁴

The classic sign of Bell’s palsy is a facial paralysis that typically occurs on one side and comes on over a matter of hours to a few days (Figure 1).^1,45 The paralysis is either partial (one-third of cases) or total (two-thirds of cases) and affects both the upper and lower facial muscles.^45,85 Sometimes both sides of the face are affected simultaneously, but this is rare; one study found that bilateral simultaneous facial palsy occurred in less than 1% of cases.⁸⁶

Figure 1. Typical manifestation
of one-sided facial paralysis
in Bell’s palsy.⁸⁷

Typically, the facial weakness worsens during the first few days and improves thereafter.^85,88 The forehead will stop furrowing and the corner of the mouth will droop on the affected side. Another feature of Bell’s palsy is an inability to close the eye as a result of the lower eyelid drooping. Attempting to close the eye can cause the eyeball to roll upward, known as Bell’s phenomenon.⁸⁹ Frowning and pursing of the lips are also impaired by Bell’s palsy.

Some individuals with Bell’s palsy describe a feeling of numbness in their face, although facial sensation is generally unchanged.⁸⁵ Bell’s palsy can impair the formation of tears (lacrimation), resulting in dryness of the eye. However, because Bell’s palsy also impairs control of the eyelids, tears may spill out of the affected eye giving the appearance of over-tearing.^85,89 In some cases, parts of the facial nerve that supply the tongue and ear can be affected resulting in loss of taste on the front two-thirds of the tongue and intensification of loud noises.⁸⁵ Bell’s palsy may produce psychologically troubling symptoms such as drooling, difficulty eating and drinking, facial distortion, and inability to smile.^6,9

In most cases, symptoms of Bell’s palsy resolve completely. However, in about 30% of cases, the facial nerve does not recover completely resulting in permanent facial muscle weakness or partial paralysis.² Another long-term complication, known as synkinesis, occurs when regenerating nerve fibers form disorganized or misdirected connections. This can cause some facial muscles to involuntarily contract along with other muscles, or tear ducts to become active during eating.² In addition, eye dryness and an inability to close the eyes completely can cause the cornea to become scratched or ulcerated, resulting in lasting vision problems.^2,9 Generally speaking, the more severe the muscle weakness or paralysis during the acute stage, the greater the likelihood for long-term muscle weakness. People who do not have some recovery within 21 days or worsen after that time should be reevaluated for other potential etiologies of facial paralysis.¹²

Consulting a physician as soon as possible after symptom onset is important because delayed diagnosis and treatment may increase the likelihood of long-term problems in some cases. Special consideration must be given in cases involving changes to hearing and the inability to close an eye, which increases the risk of corneal abrasion and ulceration.⁹

Bell’s palsy is a clinical diagnosis based on symptom history and physical exam findings.⁸⁵ The physician may ask the patient to “show me your teeth” (for palsy of lower facial muscles) and “close your eyes” (for assessing upper facial muscles). The timing of symptom onset is also important as Bell’s palsy typically has a sudden onset and progression as opposed to other causes of facial palsy such as tumors, which typically cause a gradual progression of muscle weakness over the course of weeks.⁵

A medical history that includes current or recent pregnancy, diabetes, and recent infection supports a Bell’s palsy diagnosis.⁵ Multiple family members with a history of Bell’s palsy also point to this diagnosis. Notably, certain familial cases of Bell’s palsy may be associated with increased risk of lasting problems with control of the eyelid, dry eye, and crying when eating.⁹³

Examination of the ear, mouth, head, neck, and skin is important for ruling out other possible causes of facial paralysis.⁸⁸ Notably, although Bell’s palsy is rare in children younger than 10 years old, up to 50% of reported cases of facial paralysis in this population are attributable to Lyme disease.^1,2

Additional Testing

Additional testing is not typically needed for Bell’s palsy. However, laboratory tests such as a complete blood count (CBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Lyme titer, varicella zoster antibody test, electrolytes, blood urea nitrogen (BUN), creatinine, and liver function tests may help if another cause of facial weakness is likely. Cerebrospinal fluid tests are sometimes recommended to conclusively identify infectious causes such as Lyme disease, shingles, or other viral infections.⁹ Imaging studies such as magnetic resonance imaging (MRI) may also help rule out a tumor in the case of a gradual onset of facial weakness or paralysis.⁸⁵

Electroneurography

Electroneurography can help provide prognostic information for people with complete facial muscle paralysis or those who have atypical symptoms or no improvement after several months. Electroneurography uses electricity to stimulate the facial muscle on both sides of the face. The response of the facial muscle evoked by the stimulus is lessened on the side of the face affected by Bell’s palsy, and the degree of nerve degeneration can be quantified by comparing the responses on both sides of the face.^1,94

Grading Bell’s Palsy Severity

The severity of Bell’s palsy can be graded using different scales. Two commonly used systems are the House-Brackmann Facial Nerve Grading System and Sunnybrook Facial Grading System.⁹⁵ The House-Brackmann system allows clinicians to classify facial nerve problems into six different categories based on facial muscle strength and function and appearance of the face at rest. The system also allows clinicians to evaluate progression and recovery and monitor response to treatment.^96,97 The Sunnybrook scale measures facial symmetry at rest and during voluntary and involuntary movements and scores them on a scale of 0 to 100. Although both systems can be used to help clinicians assess the severity of Bell’s palsy, they may not adequately assess aspects of Bell’s palsy such as facial comfort and problems with tearing that can affect quality of life.⁹⁵

Corticosteroids

Treatment for Bell’s palsy hinges on early intervention with corticosteroids, which are used to reduce inflammation. Multiple randomized controlled trials and meta-analyses confirm corticosteroid therapy, if initiated within 72 hours of symptom onset, increases the likelihood and speed of recovery of facial muscle function.⁹ A 10-day course of corticosteroids (ie, 10 days of 50 mg of prednisolone or 5 days of 60 mg prednisolone followed by a 5-day taper) is generally recommended.^5,9

Antiviral Medications

Antiviral medications, such as acyclovir and valacyclovir, are sometimes added to the corticosteroid regimen in severe cases, but studies have been inconclusive as to whether antivirals offer any significant benefit.^5,12,98

Eye Health Maintenance

The impaired tearing that accompanies Bell’s palsy can put the eye at risk for damage. The cornea can become dry and scratched, which can lead to permanent vision problems. It is recommended that, while awake, patients use artificial tears four times daily or every hour if needed and apply ophthalmic ointments at night. Eye patches or protective glasses may also help.¹² Targeted exercises may help in cases with residual muscle weakness or dysfunction, and specialized eyelid surgeries, such as customized weighted implants and horizontal lid tightening, may be indicated in cases of persistent inability to fully close the eyelid.⁹

Low-Level Laser Therapy

Low-level laser therapy, sometimes known as cold laser or photobiomodulation therapy, utilizes wavelengths of light between 660 nm and 905 nm. Whereas high-level laser therapy generates heat and can be used to cut or destroy tissue such as growths or tumors, low-level laser therapy stimulates tissue repair, reduces inflammation, and relieves pain without generating heat.⁹⁹ In Bell’s palsy, low-level laser therapy is believed to enhance healing and regeneration of nerves by increasing blood flow to affected tissues and decreasing inflammation.¹⁰⁰

In a randomized controlled trial in 48 subjects being treated for Bell’s palsy with facial massage and exercise, the addition of low-level laser therapy was more effective than facial massage and exercise alone.¹⁰¹ Another randomized controlled trial in 46 Bell’s palsy patients found low-level laser therapy, in conjunction with facial exercise, led to greater improvement after both three and six weeks than facial exercise alone.¹⁰² In an uncontrolled study, 11 of 14 Bell’s palsy patients experienced complete or significant recovery after 12 sessions of low-level laser therapy.¹⁰³ Another uncontrolled trial found low-level laser therapy resulted in complete recovery in 18 and partial recovery in six of 30 Bell’s palsy patients with poorly controlled type 2 diabetes who were not being treated with corticosteroids as this therapy can further worsen blood sugar regulation.¹⁰⁴

In a case report, a 3-year-old child with Bell’s palsy recovered facial muscle function after three weeks of treatment with low-level laser therapy consisting of 11 sessions lasting 15‒20 minutes each.¹⁰⁵ A positive response to three sessions of low-level laser therapy was reported in the case of a 13-year-old child with Bell’s palsy; and in a 71-year-old Bell’s palsy patient, recovery was remarkable after five sessions and complete after 10 sessions of low-level laser therapy.^106,107

Despite these promising findings, not all studies have noted efficacy, and more research is needed to identify the optimal intensity and duration of laser therapy.¹⁰⁸

Transcranial Magnetic Stimulation (TMS)

Transcranial magnetic stimulation (TMS) is a non-invasive technique that delivers magnetic pulses through the skull to stimulate nerve activity. In Bell’s palsy, repetitive TMS (rTMS) may help recovery by enhancing plasticity in motor pathways, improving blood flow to affected regions, and strengthening nerve control over muscles.^248,249

A randomized controlled trial of 65 patients with new-onset Bell’s palsy tested rTMS targeting the facial nerve region as an add-on to standard therapy, which included corticosteroids, antivirals, oral methylcobalamin, and acupuncture. The protocol used a frequency of 5 Hz with 1,800 pulses per session, five times a week for two weeks. Patients in the rTMS group showed significantly greater improvement in facial function compared with controls on three separate standardized facial neuromusculoskeletal assessments. Nearly one-quarter of patients in the rTMS group achieved complete recovery within two weeks versus none in the control group. The rTMS group experienced a 90% improvement rate after two weeks versus 53.3% in the control group. No serious adverse effects were reported.²⁵⁰

TMS has also shown potential as a prognostic tool in one study. In an observational study of 56 patients with recent onset facial palsy, TMS performed similarly to electroneuronography, another method used to measure facial nerve function. The authors concluded that TMS could aid is evaluating prognosis and setting a treatment plan.²⁵¹

One U.S. case report described a 26-year-old woman with severe acute Bell’s palsy who underwent 12 sessions of peripheral rTMS and achieved full recovery within three weeks, substantially faster than typical recovery with corticosteroid therapy alone. No adverse effects were noted.²⁴⁹

Current evidence indicates that rTMS is a safe and promising adjunctive therapy for Bell’s palsy that may promote recovery with minimal risk of adverse effects. These findings require replication and confirmation in rigorous controlled trials in diverse populations.

Facial Fillers and Botulinum Injections

Two potential long-term effects of Bell’s palsy are facial asymmetry and a condition called synkinesis, in which a voluntary facial movement results in the involuntary movement of a different facial muscle group.^109,110 A case study examined the effects of injections of facial fillers (eg, hyaluronic acid gel fillers) and botulinum toxin (Botox) injections for the treatment of a 50-year-old woman with these complications from Bell’s palsy. Multiple rounds of these treatments improved facial asymmetry and muscle spasms, reducing pain and improving her quality of life.¹¹¹ Botulinum injections can also be administered to the non-affected side of the face to improve facial symmetry and cosmetic appearance in people with Bell’s palsy.¹¹²

Hyperbaric Oxygen Therapy

Hyperbaric oxygen therapy (HBOT) is a treatment where a patient breathes pure oxygen inside a pressurized chamber, usually at 1.5 to three times normal air pressure. At this pressure, more oxygen enters the blood and is delivered to tissues in need.^113,232 This can reduce swelling, help new blood vessels form, and support nerve repair.²³³ In Bell’s palsy, where the facial nerve becomes inflamed and compressed inside a narrow bony canal, these effects may restore blood flow and promote recovery.²³⁴

A randomized controlled trial compared 42 patients who received HBOT and placebo to 37 patients who received prednisone and sham HBOT. HBOT was administered as 100% oxygen at 2.8 times ambient air pressure for 60 minutes, twice a day, five days a week until facial palsy resolved. The hyperbaric group had faster recovery (22 vs. 34 days) and higher rates of complete recovery (95% vs. 76%).¹¹⁴ However, the trial was later judged to be at high risk of bias due to unequal treatment groups and a lack of blinded outcome assessment.¹¹³

A case series of seven patients with Bell’s palsy combined HBOT with standard medical treatment. In these patients HBOT, as 100% oxygen given at 2.4 times normal air pressure for 90 minutes for up to 15 sessions, was judged to decrease recovery time. Several of the patients had sustained their improvement at the five-month follow-up visit.²³⁵

An additional case report describes a patient with Bell’s palsy who did not recover after initial treatment with prednisone and vitamin B complex. The patient underwent HBOT at 2.5 times normal air pressure for 80 minutes daily across 18 sessions, which resulted in significant improvements in facial muscle function and a reduction of Bell’s palsy symptoms.²³⁶

Middle ear pressure and/or damage (barotrauma) and claustrophobia are two common side effects of HBOT. Damage to the lens of the eye is also possible. As a modality that has not been widely adopted, access to oxygen chambers is limited, treatment schedules differ between locations, and most clinical studies are small and preliminary. Larger studies are needed to confirm whether HBOT’s benefits extend to patients with different degrees of severity or those who begin treatment at varying stages of recovery.²³⁴

Infusion Therapies

An infusion therapy, which combines high-dose corticosteroids with low-molecular-weight dextran and pentoxifylline (Trental), was first described by German physician Eberhard Stennert in 1979.²³⁷ The goal of this treatment is to improve microcirculation to promote healing.²³⁸ Stennert’s original protocol has since inspired modified versions with adjusted doses and duration while still using the combination of corticosteroids, dextran, and pentoxifylline, in some cases along with acyclovir. Case series on these methods have reported great success in treating Bell’s palsy. In several of these papers, rapid marked improvement and a high percentage of complete recovery were reported.^116,238,239

High-dose intravenous (IV) steroids may also be useful in patients who do not respond to conventional treatment. One paper described two cases in which patients had severe, long-standing facial nerve palsy that did not improve following oral steroids. Following the administration of a five-day course of IV methylprednisolone (1 gram/day), both patients began to show improvement within days after treatment, with one patient progressing from complete paralysis to partial facial movement by the end of the first week. Follow up after 1–2 years in both cases demonstrated partial recovery. However, as this was a small case report, these findings warrant further study.²⁴⁰

In addition to corticosteroids, pentoxifylline—a drug which improves circulation through damaged and narrowed blood vessels—has also been tested as an add-on to standard care. In a randomized controlled trial of 70 adults, patients were assigned to standard therapy with prednisolone plus acyclovir with or without pentoxifylline. At six months, more patients in the pentoxifylline group achieved normal function (42.9% vs. 28.6%), with particular benefit among those who began treatment within five days of symptom onset and those with moderate initial deficits.²⁴¹

Nerve Growth Factor

Nerve growth factor is a protein with neurotrophic effects. Like all neurotrophic factors, it is involved in regulating the growth, maintenance, and survival of neurons. Nerve growth factor was the first neurotrophic factor to be discovered and is widely used in China to promote nerve repair and regeneration in a range of neurological conditions, including Bell’s palsy. A meta-analysis of eight clinical trials performed in China found the inclusion of nerve growth factor in Bell’s palsy treatment was likely to improve outcomes. In the clinical trials, nerve growth factor was administered via intramuscular injections in doses of 30 mcg daily for seven days or 4 mcg daily for 7–28 days. Although the analysis of findings suggested favorable effects for nerve growth factor, the researchers were unable to draw a firm conclusion due to low quality and quantity of evidence.¹¹⁹

Low-Arginine/High-Lysine Diet

Since Bell’s palsy may be linked to reactivation of the herpes simplex virus, dietary strategies that inhibit this virus may also prove effective for treating or shortening the duration of Bell’s palsy. Arginine is an amino acid that appears to be particularly important for the replication of herpes simplex virus. Multiple studies have found that depriving herpes simplex virus of arginine can halt its replication.^120,121 On the other hand, the amino acid lysine impairs the virus’ ability to use arginine, thereby slowing viral replication. Avoiding foods such as peanuts, tree nuts, and chocolate, which are high in arginine and low in lysine, may help suppress the herpes virus.¹³

Acupuncture

Acupuncture is a traditional therapy where thin needles are placed at specific points on the body to stimulate healing. Acupuncture treatment is thought to improve blood flow and microcirculation, regulate inflammation, and support nerve repair at least in part by modulating neuroplasticity. In addition, it is widely recognized as a pain-relieving therapy. However, acupuncture treatment methods and protocols differ widely between practitioners and studies, making it difficult to reach firm conclusions about its effects and efficacy. Additionally, few studies have included a placebo group receiving sham acupuncture, a potentially important factor that future studies should attempt to take into account.²⁴²

Nevertheless, over the past two decades, both traditional and modern variations, such as electroacupuncture and laser acupuncture, have been studied for their potential role in recovery.

A systematic review and meta-analysis of 11 randomized controlled trials involving 1,258 patients compared acupuncture with standard drug therapies, including steroids, antivirals, and B vitamins. Patients treated with acupuncture achieved higher cure rates (59.7% vs. 32.5%) and greater overall improvement (96.9% vs. 83%), suggesting a meaningful advantage. The studies included all took place in China, so some degree of cultural bias cannot be ruled out; and study methodologies had multiple shortcomings. As a result, the findings require further confirmation and are not broadly generalizable.¹²² Another study in over 1,500 Chinese patients with Bell’s palsy found that use of acupuncture early in the course of the disease predicted poorer outcomes.²⁴³

One meta-analysis of 23 trials with nearly 2,000 patients found electroacupuncture to be more effective than manual acupuncture and particularly beneficial when combined with other treatments. Improvements were seen not only in facial function, but also in nerve conduction studies, providing physiological support for its effect. A later systematic review of 11 studies also found benefit from electroacupuncture, though results were inconsistent. All of the studies examined in these reviews were conducted in China, so extrapolation to Western patients and the methods used by Western acupuncture practitioners may not be reliable.^126,244

Newer techniques such as laser acupuncture therapy have also been tested. In a double-blind pilot trial of 17 individuals with long-standing Bell’s palsy, laser acupuncture therapy improved facial function scores at three weeks compared with sham treatment, and other outcome measures showed numerically greater, but not statistically significant improvement.²⁴⁵

A single-patient case report of a person with moderate intensity Bell’s palsy found full recovery after 12 sessions of manual acupuncture, electroacupuncture, and deeper penetrating needling over the course of a month.²⁴⁶

Although evidence for the effectiveness of acupuncture, especially outside of East Asia, is mixed, acupuncture is generally well-tolerated and usually has minimal adverse effects.²⁴²

Biofeedback

Biofeedback can help people with incomplete recovery from Bell’s palsy learn to control facial muscles by responding to reinforcement cues. Biofeedback strategies that use mirrors and measurements of muscle activation (electromyography or EMG) to reinforce muscle control have been shown to improve facial symmetry and reduce abnormal muscle movements in patients with long-term consequences from Bell’s palsy.^128-130 One study reported on the effect of mirror biofeedback training combined with botulinum toxin injection therapy in 27 cases of facial synkinesis following facial palsy. Improvement was noted at each of four evaluations, and lasting improvement was attributed to the biofeedback portion of treatment program.¹³¹ Another study with 22 participants found mirror biofeedback enhanced the effectiveness of standard physical rehabilitation.¹³² Other biofeedback techniques involving taping of facial regions to build sensory awareness have also been reported to improve facial muscle control.^133,134

Physical Therapy

Physical therapy may also help people with Bell’s palsy recover muscle function. While facial exercises (eg, practicing emotional expressions) may help improve muscle function and reduce involuntary facial movements in people with Bell’s palsy,¹³⁵ the overall evidence of benefit is sparce.¹³⁶ Physical rehabilitation, consisting of stretching and manual and verbal input, applied at an early stage resulted in overall improvement of the condition of Bell’s palsy patients and accelerated their recovery compared with non-rehabilitated patients.¹³⁷ The overall usefulness of physical rehabilitation therapies in Bell’s palsy is still uncertain.¹³⁸

Nutrients that promote neuronal health, quell inflammation, and inhibit viral activity may confer benefits by targeting mechanisms underlying Bell’s palsy. Other nutrient interventions that may be beneficial are described in the Inflammation and Herpes and Shingles protocols.

Vitamin B12

There is limited evidence that vitamin B12 may provide benefits in the treatment of Bell’s palsy, but it is often mentioned in articles discussing Bell’s palsy treatment given its ubiquity and safety and the biological plausibility for potential benefit. Indeed, case reports dating back to the 1950s reported success with the use of B12 in treating Bell’s palsy, although these older studies often lacked methodological rigor.²⁴⁷ In general, the totality of the available evidence is from small studies that lacked robust designs, so cannot be regarded as conclusive at this time. Nevertheless, vitamin B12 is safe and inexpensive, so there is likely little downside to incorporating it into a treatment regimen.

In an open-label, randomized, single-center trial in Malaysia, 60 subjects who had recently developed Bell’s palsy received either prednisolone alone, vitamin B12 (as methylcobalamin), or B12 plus prednisolone. Vitamin B12 was dosed at 500 mcg intramuscularly three times per week for at least eight weeks or until recovery; the prednisolone dosage was 60 mg/day tapered over three weeks. The primary outcomes were time to complete facial nerve recovery (as assessed by a standardized facial nerve scale) and weekly facial nerve scores, with concomitant symptoms tracked separately. Patients in the B12 groups recovered much faster than those taking steroids alone. Those taking B12 had facial nerve recovery in about two weeks compared with 9.6 weeks in those taking only steroids. Although this study is intriguing, it was not placebo-controlled, had small groups (20 per arm), and short measured follow-up.¹⁴

A meta-analysis that included five studies (344 people with Bell’s palsy) found that B12 plus acupuncture was associated with higher rates of complete recovery than acupuncture alone. However, due to the poor methodological quality of these studies, no meaningful conclusions about the overall efficacy of B12 could be reached; the authors recommended additional, more rigorous studies.¹⁴¹

In a retrospective study of 513 Chinese inpatients with Bell’s palsy, researchers looked for factors associated with recovery at hospital discharge and at final follow-up. Early use of steroids was associated with greater improvement at discharge than no steroids (92.5% vs. 57.3%), while longer delays before treatment, having other illnesses, and early acupuncture were linked with worse discharge outcomes. Subgroup analyses suggested similar benefits associated with starting steroids plus antivirals or steroids plus methylcobalamin. However, antivirals plus methylcobalamin without steroids performed worse than the steroid-containing options. Specific dosages of the interventions used were not reported in this study.²⁴³

Acetyl-L-Carnitine

Acetyl-L-carnitine, a compound found throughout both the central and peripheral nervous systems, plays a role in several processes, including the processing of fatty acids. A randomized placebo-controlled trial in 43 subjects with idiopathic facial palsy found those given 3 grams of oral acetyl-L-carnitine along with 50 mg methylprednisolone daily for 14 days had more rapid functional recovery of the facial nerve compared with those given methylprednisolone plus placebo. After 10 days of treatment, a measure of paralysis was reduced by half in the acetyl-L-carnitine group but unchanged in the placebo group.¹⁵ Additionally supporting the use of acetyl-L-carnitine are studies with the nutrient in other conditions involving nerve damage. Preclinical research showed acetyl-L-carnitine prevented and mitigated nerve pain caused by the chemotherapy drug paclitaxel (Abraxane).¹⁴³ Two clinical studies found acetyl-L-carnitine to be effective for treating various forms of neuropathy, including diabetic and drug-induced neuropathies.¹⁴⁴

Additional Support

Given the relatively benign nature of Bell’s palsy, its typically limited disease course, and good prognosis in most cases, few human clinical trials have examined nutritional interventions. Nevertheless, owing to the inflammation and nerve involvement in Bell’s palsy, several nutrients that promote neuronal health and mitigate inflammation may be helpful.

Niacin. Niacin (vitamin B3) is a vitamin that can cause blood vessels to dilate, which is why it causes flushing in many people. This increased blood flow has been proposed to help speed the healing of the facial nerve. Some evidence suggests niacin, administered orally or via intramuscular injection, may be useful in treating Bell’s palsy, although data are very limited. In an older series of 74 cases treated with 100‒250 mg niacin, all but one case resulted in good facial nerve response within 2‒4 weeks, such that an observer would be unable to point out which side of the face was paralyzed. In 39 of the 74 cases, treatment began within two days of the onset of paralysis and these individuals had complete recovery within 14 days.¹⁴⁵

Omega-3 fatty acids. Omega-3 fatty acids can reduce inflammation in the body. The omega-3 fatty acids commonly obtained from fish, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), inhibit signaling of a pro-inflammatory molecule called nuclear factor-kappa B (NF-ĸB) and reduce levels of other chemicals that trigger inflammation, such as tumor necrosis factor-alpha (TNF-α) and interleukin-6.¹⁴⁶ These fatty acids are also metabolized into compounds called resolvins that protect nerves from inflammatory damage.¹⁴⁷ Some preclinical evidence suggests omega-3 fatty acids may help improve recovery after nerve damage while in healthy people they have been shown to improve motor nerve function.¹⁴⁸ In type 1 diabetics, fish oil supplementation has also been shown to significantly improve nerve growth.¹⁵⁰ While no studies have been carried out in the context of Bell’s palsy, it is reasonable to suggest omega-3 fatty acids may offer some support for inflammatory nerve damage and recovery of function.

Ginkgo. Numerous studies indicate ginkgo (Ginkgo biloba) leaf extract has neuroprotective effects,¹⁵¹ which may make it a helpful therapeutic for Bell’s palsy. For example, ginkgo has been found to inhibit free radical damage to nerve cell membranes, reduce neuroinflammation, improve neuronal mitochondrial function and energy production, and promote nerve growth and formation of neuronal connections.^152-155 In preclinical studies, ginkgo extracts have been found to enhance nerve healing after injury related to trauma, toxin exposure, ischemia (lack of oxygen), and oxidative stress.^156-160 An active component from ginkgo was found to promote regeneration of myelin in part by reducing inflammatory signaling in animal and cellular models of a demyelinating disorder.¹⁵³ A compound from ginkgo has also demonstrated antiviral activity against herpes viruses in the laboratory.¹⁶¹

Curcumin. Curcumin, a carotenoid found in turmeric that has potent anti-inflammatory properties, has been shown to help protect against nerve damage caused by diabetes and alcohol, possibly by protecting neurons from inflammation-induced damage.^18,19 Specifically, curcumin is able to reduce inflammation by increasing the activity of proteins that inhibit the activity of NF-ĸB, a major trigger for inflammation. Curcumin has been shown to protect neurons from damage in preclinical models of stroke, Alzheimer disease, and oxidative stress.^20,162-164

Green tea extract. Green tea contains high amounts of polyphenols known as catechins, including epigallocatechin gallate (EGCG), that scavenge free radicals, inhibit oxidative injury, and lower oxidative stress levels. Preclinical research indicates EGCG may specifically protect neurons by suppressing inflammatory signaling by activated immune cells in the nervous system and promoting release of an important nerve growth factor called brain-derived neurotrophic factor (BDNF).^165,166 Animal research suggests EGCG may also reduce body-wide and nervous system inflammation related to metabolic disorders, which increase the risk of Bell’s palsy.^167,168 Animal models show EGCG may play a role in preventing a range of neurological disorders.^165,169,170

Vitamin E. Vitamin E, comprising tocopherols and tocotrienols, has free radical-scavenging and anti-inflammatory effects. It has particular neuroprotective effects because of its nature as a lipid compound, and has been suggested to be beneficial in a range of neurological disorders.^171-173 Studies in animals have shown vitamin E has the potential to protect against oxidative and inflammation-related nerve damage.^173-175 Other animal research indicates adequate vitamin E levels are needed for an effective immune response to HSV infection.¹⁷⁶

Alpha-lipoic acid. Alpha-lipoic acid, a free radical-scavenging nutrient involved in glucose and fat metabolism,^177,178 is used to treat metabolic disorders like obesity and diabetes, as well as neurological complications such as diabetic neuropathy, dry eyes, and retinopathy.^179-181 Alpha-lipoic acid has been shown to improve nerve function in animal and laboratory models of neurological dysfunction, as well as in some clinical research.¹⁷⁸

Licorice. Licorice (Glycyrrhiza glabra) has been used traditionally to combat viral infections. It contains compounds that exert strong anti-inflammatory effects and have demonstrated antiviral activity against several viruses, including HSV-1 and varicella zoster virus, in preclinical studies.^21,182,183

Zinc. Zinc is an important nutrient for normal nerve function, and deficiency can cause hearing and taste disturbances and contribute to depression and neurological disorders.¹⁸⁴ Zinc supports nerve growth and the formation of new neuronal connections.¹⁸⁵ It also inhibits the replication of HSV-1 and has been effectively used in multiple clinical trials to reduce the duration of herpes outbreaks.^13,186

Lysine. Lysine is an amino acid sometimes used to treat HSV infections.²² A double-blind placebo-controlled trial that included participants with oral-facial or genital herpes found consuming 1 gram L-lysine three times daily for six months reduced the frequency, duration, and severity of herpes outbreaks.²³ Findings from other studies suggest lysine supplementation, particularly at doses higher than 3 grams per day, may reduce frequency, shorten duration, and decrease severity of cold sores due to HSV, but the quality of supportive evidence is low.^29,187 Although lysine has not been evaluated in the context of Bell’s palsy, its possible anti-herpes activity suggests it may be helpful.

Reishi mushroom. Reishi mushroom (Ganoderma lucidum) has been used medicinally for centuries in China, Japan, and Korea.¹⁸⁸ Researchers have identified two different compounds in the reishi mushroom, known as GLPG (Ganoderma lucidum proteoglycan) and APBP (acidic protein bound polysaccharide), that showed strong antiviral activities against both HSV-1 and HSV-2 in the laboratory setting.^189-191 Reishi compounds have also been shown to reduce inflammation, lower oxidative stress, and strengthen immune defenses.¹⁹²

Herbal preparations containing reishi mushroom have shown promising results in uncontrolled clinical trials in subjects with herpes virus outbreaks. A combination of six medicinal herbs, including reishi, was reported to reduce pain caused by shingles in five cases. Other trials reported the same reishi-containing herbal mixture reduced pain and shortened symptom duration in patients with recurrent oral and genital herpes outbreaks.^193-195

Lemon balm. Lemon balm (Melissa officinalis) is a plant in the mint family used traditionally to treat herpes outbreaks and other viral infections.¹⁹⁶ Multiple laboratory experiments have shown lemon balm extracts possess antiviral activities against both HSV-1 and HSV-2.^197-203 Clinical trials have evaluated the efficacy of topical lemon balm preparations and shown positive results. In a double-blind placebo-controlled trial with 66 participants, a lemon balm ointment, applied four times daily for five days, improved symptoms of oral herpes, shortened healing time, and prevented spread of the infection. The authors further suggested lemon balm may increase time between outbreaks.²⁰⁴ Two additional trials involving 115 and 116 patients found topical therapy with lemon balm extract eased oral herpes symptoms and was most effective when used early.²⁰⁵ Lemon balm has also been noted to protect nerves from injury due to inflammation, hypoxia (low oxygen level, such as due to poor circulation), and oxidative stress in laboratory and animal models.^206-209

Propolis. Propolis, a resin-like substance obtained from beehives, has a long history of medicinal use.²¹⁰ It contains a mixture of several compounds, including flavonoids and other polyphenols, that have strong anti-inflammatory and oxidative stress-reducing effects.²¹¹ Some propolis-derived compounds have demonstrated antimicrobial activity, including antiviral activity against HSV-1 and HSV-2.^211-213 Comprehensive reviews have suggested propolis may be beneficial in treating herpes virus-related skin lesions, but available research is not high quality.^214,215 In clinical trials in subjects with herpes lesions on the lips, a 0.5% topical propolis extract solution was more effective than topical use of the antiviral drug acyclovir for shortening time to healing and reducing symptoms such as pain, burning, itching, tension, and swelling.^216,217 With its combination of antiviral and anti-inflammatory properties, propolis has the potential to be beneficial in Bell’s palsy.

Fucoidans. Fucoidans are naturally occurring polysaccharides found in edible brown algae that have been found to promote balanced immune function in preclinical models.²¹⁸ They also strengthen the antiviral immune response and demonstrate direct antiviral actions, including against HSV-1 and HSV-2, in preclinical research.^219-221 Additionally, fucoidans have the capacity to reduce inflammation and oxidative stress.²¹⁸ A report on two case studies noted use of a topical 4% fucoidan cream markedly decreased healing time associated with recurrent oral herpes outbreaks.²²²

Other anti-inflammatory and antiviral nutrients. Several other nutrients with anti-inflammatory, antiviral, and neuroprotective properties may play a role in speeding healing and recovery in patients with Bell’s palsy. These include vitamins A, C, and D.^223-228 Flavonoids such as resveratrol and quercetin, as well as flavonoid-rich elderberry extract, also have these properties and have the potential to help promote Bell’s palsy recovery.^228-230 Probiotics may modulate immune function and support neuronal health and regeneration.²³¹