Phenylalanine supplement for depression

Phenylalanine is an essential amino acid, which means you need it in your diet. Amino acids are the building blocks of protein. Phenylalanine is especially important to young, growing children. Adults need less phenylalanine in their diet. High doses of phenylalanine supplements can lead to insomnia.

L Phenylalanine and cefdinir drug combination
Effect of L-phenylalanine supplementation and a high-protein diet on pharmacokinetics of cefdinir in healthy volunteers: an exploratory study.
J Clin Pharm Ther. 2007 Jun;32(3):277-85. Department of Pharmacology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan.
Upregulation of oligopeptide transport activity by dietary protein, certain dipeptides and amino acids has been reported in the rat intestine and a human intestinal cell line. In this study, the pharmacokinetics of cefdinir were investigated after L-phenylalanine supplementation and a high-protein diet (HPD) in humans to explore changes in the activities of intestinal and renal oligopeptide transporters. A normal-protein diet, NPD + l-phenylalanine (7.5 g/day), or HPD was given to six male healthy volunteers for 12 days followed by a single dose of cefdinir after an overnight fast in a randomized three-way crossover study with a 22-day washout. Plasma concentrations and urinary excretion of the drug did not change throughout the study. Physiological variables and laboratory values did not reveal any differences between the three periods except for serum and urinary nitrogen levels and serum triglyceride. A reason for the unchanged pharmacokinetics of cefdinir may be due to lower doses of L-phenylalanine and protein in humans than in animals when converting animal effective doses to humans. In humans, L-phenylalanine supplementation and HPD do not seem to upregulate intestinal and renal oligopeptide transport in the ranges of duration and dose examined.

Phenylketonuria and phenylalanine
Brain phenylalanine concentrations in phenylketonuria: research and treatment of adults.
Pediatrics. 2003 Dec;112(6 Pt 2):1575-9. Moats RA, Moseley KD, Koch R, Nelson M Jr. Department of Radiology, University of California/Keck School of Medicine at Childrens Hospital Los Angeles, Los Angeles, California 90027, USA.
To assess the effects of 2 pharmacologic interventions (amino acid supplements) on the brain levels of phenylalanine  in adults with phenylketonuria. A prospective study was conducted in an outpatient treatment and follow-up setting. The volunteers who were recruited for the first intervention included 4 subjects with classic phenylketonuria. The second intervention included 3 adults with classic phenylketonuria. The first intervention consisted of dietary supplementation during 1 day with Phlexy 10. Two individuals were given a dose of 0.5 g/kg/d, and 2 were given 1.0 g/kg/d. The second intervention consisted of dietary supplementation with PreKUnil at 0.4 g kg/d over a period of 6 months. Brain phenylalanine was measured by magnetic resonance spectroscopy. The number of the patients involved precluded analysis for significance. The first, shorter intervention resulted in a decrease in brain phenylalanine. The second intervention resulted in a 20% decrease in brain phenylalanine, which was maintained after 6 months of treatment. Dietary supplementation of large neutral amino acids seems to lower the brain phenylalanine in adults who have phenylketonuria and have difficulty following their diet.

Phenylalanine questions
Q. My wife has been taking a supplement with combination of 200mg of L-Tyrosine and 300mg of DL Phenylanaline for over a year with positive results. She recently stopped taking it. What effects, depression for example, are likely if such a treatment is suddenly stopped?
   A. Each person is different, some may experience hardly any withdrawal symptoms while others may find low energy or mood, but human research is lacking in this area so we can't say much more with confidence.

Q. Can DL phenylalanine product be taken with a product that contains St. Johns wort and 5htp?
   A. It is not easy to give such answers because different users can have different reactions and much depends on the dosages of the supplements used and the timing of their use.

Q. My wife has been taking a supplement with combination of 200mg of L-Tyrosine and 300mg of DL Phenylanaline for over a year with positive results. She recently stopped taking it. What effects, depression for example, are likely if such a treatment is suddenly stopped?
   A. Each person is different, some may experience hardly any withdrawal symptoms while others may find low energy or mood, but human research is lacking in this area so we can't say much more with confidence.

Q. Does the phenylalanine in diet sodas convert to tyrosine?
   A. Possibly, but we suspect the amount of phenylalanine in diet sodas is not that high.

back to index yohimbe bark