Phenylalanine
Overview
Phenylalanine (C9H11NO2) is an essential aromatic amino acid converted by phenylalanine hydroxylase to tyrosine, then to dopamine, noradrenaline, melanin, and thyroid hormones. In phenylketonuria (PKU), PAH deficiency causes neurotoxic accumulation. A Cochrane review found tyrosine supplementation in PKU raises tyrosine levels but shows no significant neuropsychological benefit. D,L-phenylalanine (DLPA) inhibits enkephalin degradation (analgesic). Critical: contraindicated with MAO inhibitors (risk of hypertensive crisis). No EFSA-authorized health claims.
Dosage
500 mg · Any time · Can take on empty stomach
Key Interactions
25 verified interactions found
Hohe Phenylalanin-Spiegel reduzieren die Verfügbarkeit von Tryptophan und Tyrosin im Gehirn. Die Synthese von Serotonin und Dopamin kann dadurch beeinträchtigt werden.
Phenylalanin konkurriert mit Tryptophan um denselben Transportmechanismus über die Blut-Hirn-Schranke. Für optimale Tryptophan-Wirkung (z.B. Stimmungsunterstützung) mindestens 2h Abstand zur Phenylalanin-Einnahme einhalten.
View details →Ein erhöhtes Phenylalanin/Tyrosin-Verhältnis weist auf verminderte Phenylalanin-Hydroxylase-Aktivität hin und kann die Tyrosin-abhängige Neurotransmittersynthese beeinträchtigen.
Phenylalanin ist die Vorstufe von Tyrosin; hohe Phenylalanin-Dosen können Tyrosin-Spiegel und -Verfügbarkeit beeinflussen. Bei gezielter Tyrosin-Supplementierung zeitversetzt einnehmen (mindestens 2h Abstand).
View details →Melatonin and phenylalanine show an inverse relationship in blood levels in individuals.
Hohe Phenylalanin-Spiegel können den Melatonin-Spiegel senken. Wer Melatonin zur Schlafregulation einnimmt, sollte auf sehr hohe Phenylalanin-Dosen kurz vor dem Schlafengehen verzichten.
View details →Phenylalanine inhibits HMG-CoA reductase, reducing both cholesterol and CoQ10 synthesis.
Phenylalanin hemmt Enzyme des Mevalonat-Stoffwechsels, über den auch Ubichinon (CoQ10) synthetisiert wird; dies könnte die körpereigene CoQ10-Produktion beeinflussen. Bei gezielter CoQ10-Supplementierung und gleichzeitiger Phenylalanin-Einnahme ist kein akuter Handlungsbedarf gegeben.
View details →High phenylalanine levels may inhibit biotin metabolism, potentially requiring higher biotin supplementation.
Hohe Phenylalanin-Spiegel können die Biotinidase-Aktivität hemmen und die Biotinverfügbarkeit beeinflussen. Bei Phenylketonurie oder sehr hohen Phenylalanin-Dosen empfiehlt sich eine ausreichende Biotin-Versorgung.
View details →Scientific Sources
- Source
- Source
- Acetylcholinesterase activity and biogenic amines in phenylketonuria. (2002)
- The role of tryptophans on the cellular uptake and membrane interaction of argin (2015)
- 5-Hydroxytryptophan during critical postnatal period improves cognitive performa (2011)
- Inhibition byl-phenylalanine of tryptophan transport by synaptosomal plasma memb (2006)
- GGA1 Interacts with the Adaptor Protein AP-1 through a WNSF Sequence in Its Hing (2004)
- Pegylated interferon-&agr;2b treatment in melanoma patients: influence on amino (2004)
- The beta-agonist cimaterol directly enhances chronic protein accretion in skelet (1998)
- Fyn‐dependent phosphorylation of PlexinA1 and PlexinA2 at conserved tyrosines is (2018)
- Post-Translational Incorporation of L-Phenylalanine into the C-Terminus of α-Tub (2016)
- Rate of Phenylalanine Hydroxylation in Healthy School-Aged Children (2011)
- Evaluation of Tetrahydrobiopterin Therapy with Large Neutral Amino Acid Suppleme (2016)
- Exogenous Melatonin Reduces Lignification and Retains Quality of Green Asparagus (2021)
- Inhibition of downy blight and enhancement of resistance in litchi fruit by post (2021)
- Coenzyme Q10 in phenylketonuria and mevalonic aciduria. (2007)
- Ubiquinone-10 content in lymphocytes of phenylketonuric patients. (2002)
- [In vitro metabolism of ubiquinone and ubichromenol in the livers of rats with a (1976)
- Plasma creatine kinase and cardiomyopathy in glycogen storage disease type III (2006)
- NIH Dietary Supplement Label Database (DSLD)
- PubChem Compound 6140
Frequently Asked Questions
What is Phenylalanine used for?
Phenylalanine (C9H11NO2) is an essential aromatic amino acid converted by phenylalanine hydroxylase to tyrosine, then to dopamine, noradrenaline, melanin, and thyroid hormones.
What is the recommended dosage for Phenylalanine?
500 mg. Any time. Can take on empty stomach.
Does Phenylalanine interact with other supplements?
Phenylalanine has 25 verified interactions. Top: Tryptophan, Tyrosine.
When is the best time to take Phenylalanine?
Any time. Can take on empty stomach.
Is Phenylalanine safe to combine with other supplements?
Always check interactions before combining supplements. Use VitalStack to verify your full stack for free.
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Check Your Stack →Not medical advice. VitalStack is not a medical device. For personalized health recommendations, consult a healthcare provider.