Phenylalanine is an essential amino acid meaning the body needs this ingredient and is unable to produce it naturally.
Phenylalanine (which converts into Phenylethylamine) must be obtained either through supplementation or food sources including meats and milk products, oats, and wheat germ.
In order to make the use of this supplement most effective, the body also needs vitamins B3, B6, C, copper, and iron.
As an amino acid, Phenylalanine helps to make proteins in the body. There are also several different forms of this supplement: L-Phenylalanine, D-Phenylalanine, and DL-Phenylalanine (this last is a combination of the prior two forms).



- Precursor for the production of dopamine
- Supports mood & combats stress
- Boosts energy & mental focus
Phenylalanine Roles in the Body
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This supplement is also critical to the normal functioning of the central nervous system, especially regarding symptoms like depression and chronic pain along with a number of additional diseases that have been linked to a malfunctioning nervous system.
It is also used in the formation and synthesis of a number of different neurotransmitters like epinephrine, dopamine, and norepinephrine. All of these chemicals are vital for the proper functioning of the nervous system.
As a nootropic, Phenylalanine has many different positive effects including mood enhancement, anxiety relief, increased focus and concentration, and improved motivation.
Phenylalanine Effects:
Although the specific mechanisms of action for Phenylalanine are still not fully understood, it is known that this supplement crosses the blood-brain barrier and enters into the central nervous system.
This ‘barrier’ is a protective defense of red blood cells and the glia of the brain which does not allow toxins, bacteria, or viruses to enter into the brain and nervous system. However, this barrier also keeps out many potentially beneficial compounds. The fact that Phenylalanine can cross the blood-brain barrier is integral to its effectiveness as a cognitive enhancement supplement.
One of the most critical ways in which this supplement is thought to work is in the synthesis of neurotransmitters, especially dopamine, norepinephrine, and epinephrine. Recent research also suggests that Phenylalanine aids in the production of melatonin (which is vital for controlling and regulating the sleep and wake cycles).
This supplement is used to form tyrosine, another amino acid. Tyrosine itself is thought to be useful in the treatment of things like anxiety and depression. It is also important to proper metabolic function and can aid in the reduction of body fat.
Phenylalanine Benefits:
There are a number of key benefits to the brain for using Phenylalanine supplementation. This includes helping to improve the memory, enhance overall alertness, and possibly expand learning capacity. The supplement also enables the overall nervous system to operate more efficiently.
Signals which carry information from neuron to neuron are conducted faster and more effectively. Primarily due to these effects, Phenylalanine is currently being used in the treatment of depression, bipolar disorder, hyperactivity, and Parkinson’s disease.
This amino acid is also thought to function as an effective pain reliever. This is particularly true for migraines and other headaches. Phenylalanine also appears to be quite effective for other types of pain including the lower back and neck, arthritis, and menstrual cramps.
There is also evidence suggesting that it is helpful for many types of chronic pain, even those which begin with an injury or accident involving physical trauma. The supplement appears to work through up-regulation of your endogenous analgesia system which actually suppresses nerve transmissions in your pain pathways.
Phenylalanine may also help to improve conditions like anxiety and depression. Many of the neurotransmitters produced by this supplement are effective at improving overall mood and impart a feeling of greater well-being that can help with stress levels, relieve anxiety, and even combat feelings of depression. Using Phenylalanine can put you in a positive state of mind and lead to better emotional balance.
Phenylalanine Dosage:
There seems to be a fairly wide range of effective dosages for Phenylalanine.
Clinical studies and research have used anywhere from 100 mg to 5,000 mg per day. Typical users will stick to the 1,000 to 2,000 mg range per day.
It is also common to stack Phenylalanine supplements with Hordenine which is a compound that prevents the break-down of this nootropic. The result is a greater duration of effects for Phenylalanine and more noticeable improvements in mood.
Phenylalanine Side Effects:
While this supplement is considered to be generally safe and very well-tolerated there are some associated side effects. These include nausea, headaches, and heart burn. This should also not be taken by people currently using anti-psychotic medication and specific anti-depressants (monoamine oxidase inhibitors). Always consult with a doctor or qualified medical professional before adding a new supplement to your regimen.
Phenylalanine Review:
As an essential amino acid, using Phenylalanine supplement does offer a lot of benefits. The Nootropic properties of increased attention, inhibition control, and drive make this an ideal study supplement or productivity pill.
This natural compound can also be used in a stack to alleviate stress and anxiety while putting you in a positive state of mind. Phenylalanine also has medicinal benefits for those suffering with pain issues.
If you are interested in using this supplement, you will typically see its metabolites for sale instead: you can buy Phenylethylamine and Tyrosine more easily than Phenylalanine.
- Tumilty L, Davison G, Beckmann M, Thatcher R. Acute oral administration of a tyrosine and phenylalanine-free amino acid mixture reduces exercise capacity in the heat. Eur J Appl Physiol. 2013
- Bjork JM, Grant SJ, Chen G, Hommer DW. Dietary tyrosine/phenylalanine depletion effects on behavioral and brain signatures of human motivational processing. Neuropsychopharmacology. 2014
- Linssen AM, Riedel WJ, Sambeth A. Effects of tyrosine/phenylalanine depletion on electrophysiological correlates of memory in healthy volunteers. J Psychopharmacol. 2011
- Ramdani C, Carbonnell L, Vidal F, Béranger C, Dagher A, Hasbroucq T. Dopamine precursors depletion impairs impulse control in healthy volunteers. Psychopharmacology (Berl). 2015
- ten Hoedt AE, de Sonneville LM, Francois B, ter Horst NM, Janssen MC, Rubio-Gozalbo ME, Wijburg FA, Hollak CE, Bosch AM. High phenylalanine levels directly affect mood and sustained attention in adults with phenylketonuria: a randomised, double-blind, placebo-controlled, crossover trial. J Inherit Metab Dis. 2011
- Opladen T, Okun JG, Burgard P, Blau N, Hoffmann GF. Phenylalanine loading in pediatric patients with dopa-responsive dystonia: revised test protocol and pediatric cutoff values. J Inherit Metab Dis. 2010
- Sano H, Murakami S, Sasaki S, Al-Mamun M. Effects of dietary energy intake and cold exposure on kinetics of plasma phenylalanine, tyrosine and protein synthesis in sheep. Arch Anim Nutr. 2010
- Kravitz HM, Sabelli HC, Fawcett J. Dietary supplements of phenylalanine and other amino acid precursors of brain neuroamines in the treatment of depressive disorders. J Am Osteopath Assoc. 1984
- Moats RA, Moseley KD, Koch R, Nelson M Jr. Brain phenylalanine concentrations in phenylketonuria: research and treatment of adults. Pediatrics. 2003
- Hardman CA, Herbert VM, Brunstrom JM, Munafò MR, Rogers PJ. Dopamine and food reward: effects of acute tyrosine/phenylalanine depletion on appetite. Physiol Behav. 2012
- Okusaga O, Muravitskaja O, Fuchs D, Ashraf A, Hinman S, Giegling I, Hartmann AM, Konte B, Friedl M, Schiffman J, Hong E, Reeves G, Groer M, Dantzer R, Rujescu D, Postolache TT. Elevated levels of plasma phenylalanine in schizophrenia: a guanosine triphosphate cyclohydrolase-1 metabolic pathway abnormality? PLoS One. 2014
- Wissmann P, Geisler S, Leblhuber F, Fuchs D. Immune activation in patients with Alzheimer's disease is associated with high serum phenylalanine concentrations. J Neurol Sci. 2013
- Akimitsu O, Wada K, Noji T, Taniwaki N, Krejci M, Nakade M, Takeuchi H, Harada T. The relationship between consumption of tyrosine and phenylalanine as precursors of catecholamine at breakfast and the circadian typology and mental health in Japanese infants aged 2 to 5 years. J Physiol Anthropol. 2013
- Vrshek-Schallhorn S, Wahlstrom D, White T, Luciana M. The effect of acute tyrosine phenylalanine depletion on emotion-based decision-making in healthy adults. Pharmacol Biochem Behav. 2013
- Jukić T, Rojc B, Boben-Bardutzky D, Hafner M, Ihan A. The use of a food supplementation with D-phenylalanine, L-glutamine and L-5-hydroxytriptophan in the alleviation of alcohol withdrawal symptoms. Coll Antropol. 2011
- Hildebrand P, Königschulte W, Gaber TJ, Bubenzer-Busch S, Helmbold K, Biskup CS, Langen KJ, Fink GR, Zepf FD. Effects of dietary tryptophan and phenylalanine-tyrosine depletion on phasic alertness in healthy adults - A pilot study. Food Nutr Res. 2015
- Kapatos G, Zigmond M. Dopamine biosynthesis from L-tyrosine and L-phenylalanine in rat brain synaptosomes: preferential use of newly accumulated precursors. J Neurochem. 1977
Article last updated on: March 13th, 2018 by Nootriment
5 Comments
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