D, L-Phenylalanine Capsules

  • 500 mg, 100 vegetarian capsules
  • Item # 01671
D, L-Phenylalanine Capsules 500 mg, 100 vegetarian capsules - Life Extension

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Supplement Facts for D, L-Phenylalanine Capsules 500 mg, 100 vegetarian capsules

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D, L-Phenylalanine Capsules

  • 500 mg, 100 vegetarian capsules
  • Item # 01671

Promotes mood & neurotransmitter health

Phenylalanine supplementation helps in the production of healthy neurotransmitters (dopamine, norepinephrine and epinephrine). Clinical trials suggest it may promote positive moods.
Gluten free Non-GMO Vegetarian
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Works well for me.

Reetz, Syracuse NY

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  • This Item: D, L-Phenylalanine Capsules, 500 mg, 100 vegetarian capsules
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D, L-Phenylalanine Capsules

500 mg, 100 vegetarian capsules


$0.14/count | 100 Day Supply

Phenylalanine is an essential amino acid, which means your body can’t produce sufficient amounts and requires it from an external source. It’s converted to L-tyrosine in the liver, which is then converted into dopamine, norepinephrine and epinephrine (adrenaline) hormones that can become depleted for a variety of reasons. Replenishing norepinephrine in the brain can support brain health.

The neurotransmitters produced from phenylalanine supplementation bring a wide range of cognitive health benefits.

D, L-Phenylalanine Benefits

  • Supports production of L-tyrosine, which is used to make dopamine, norepinephrine & epinephrine
  • Helps promote healthy mood & sleep
  • Supports healthy cognitive function
  • Provides protection for brain cells

Essential Nutrient to Support Mood and Cognitive Health

D,L-phenylalanine is a 50/50 mixture of its two stereoisomers that can be converted to L-tyrosine in the liver, which is then used to make dopamine, norepinephrine and epinephrine. In addition to acting as a neurotransmitter that supports healthy mood and sleep, norepinephrine is known to protect brain cells by promoting a healthy inflammatory response, inhibiting oxidative stress and supporting healthy neuronal growth.

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Phenylalanine is an essential amino acid that can be converted to L-tyrosine in the liver. Tyrosine is used in the nervous system to make a class of neurotransmitters called catecholamines: dopamine, norepinephrine and epinephrine. Epinephrine, made from tyrosine in the adrenal medulla, functions as a neurohormone and is known as adrenaline.1

These statements have not been evaluated by the Food and Drug Administration.
These products are not intended to diagnose, treat, cure, or prevent any disease.
  1. J Nutr. 2007;137(6 Suppl 1):1539S-1547S; discussion 1548S.
  2. J Neurochem. 2016;139 Suppl 2:154-178.
  3. Neurosci Biobehav Rev. 2006;30(6):791-807.
  4. Neurosci Biobehav Rev. 2010;34(5):670-7.
  5. Eur J Nucl Med Mol Imaging. 2012;39(9):1462-6.
  6. J Psychiatr Res. 2015;70:50-7.
  7. Biochem Biophys Res Commun. 2012;426(1):148-52.
  8. Biochim Biophys Acta Gen Subj. 2017;1861(12):3142-3153.
  9. Arch Psychiatr Nervenkr (1970). 1979;227(1):49-58.
  10. J Neural Transm. 1977;41(2-3):123-34.

Serving Size 1 vegetarian capsule

Amount Per Serving


500 mg

Other ingredients: vegetable cellulose (capsule), vegetable stearate, microcrystalline cellulose.

Dosage and Use
  • Take one (1) capsule daily on an empty stomach in the morning, or as recommended by a healthcare practitioner. Best utilized if taken with the co-factors vitamins B6 and C.

May cause anxiety, high blood pressure, and headache. Do not use if you have phenylketonuria. Do not use phenylalanine or tyrosine if you have cancer or muscular dystrophy. Because phenylalanine can elevate blood pressure in hypertensives, consult your healthcare practitioner if you have hypertension. Insomnia may occur from overstimulation if taken too close to bedtime.

  • Do not purchase if outer seal is broken or damaged.
  • When using nutritional supplements, please consult with your physician if you are undergoing treatment for a medical condition or if you are pregnant or lactating.

To report a serious adverse event or obtain product information, contact 1-866-280-2852.

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