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D, L-Phenylalanine Capsules

500 mg, 100 vegetarian capsules
Item# 01671


D, L-Phenylalanine Capsules

Promotes mood and neurotransmitter health

500 mg, 100 vegetarian capsules
Item# 01671


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  • D, L-Phenylalanine Capsules
  • 500 mg, 100 vegetarian capsules
  • Item Catalog Number: 01671

L-phenylalanine is an essential amino acid that can be converted to L-tyrosine in the liver. L-tyrosine can be converted in the brain and in the adrenal glands to dopamine, norepinephrine, and epinephrine (adrenaline) hormones that are depleted by stress, overwork and certain drugs. By replenishing norepinephrine in the brain, mental energy levels are enhanced and a feeling of contentment often occurs. The conversion step from L-tyrosine to norepinephrine may be enhanced if the co-factors (vitamins B6 and C) are included.1-7

Cells in the adrenal medulla synthesize and secrete norepinephrine and epinephrine. Since both norepinephrine and epinephrine can cause smooth muscle (arterial) contraction, care with blood pressure should be taken when supplementing with L-phenylalanine.

D,L-phenylalanine is a 50/50 mixture of its two stereoisomers.

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 Psychiatry Neurosci. 2001 May;26(3):247-51.
  2. Acta Paediatr Suppl. 1994 Dec;407:86-8.
  3. Med Sci Sports Exerc. 2001 Dec;33(12):2104-10.
  4. Brain Res Bull. 1999 Jan 15;48(2):203-9.
  5. Pharmacol Biochem Behav. 1976 Jul;5(1):47-53.
  6. Clin Neuropharmacol. 2000 Jul-Aug;23(4):212-5.
  7. Aviat Space Environ Med. 1992 May;63(5):364-9.


Supplement Facts

Serving Size 1 vegetarian capsule

Amount Per Serving


500 mg

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

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.



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