L-Phenylalanine
Phenylalanine is an essential amino acid that comes from food and is the starting material for tyrosine.
Can it improve mood?
A 1979 study compared DL-phenylalanine, 150–200 mg daily, with imipramine for 30 days in 40 people with depression; 27 completed treatment. Overall depression ratings did not differ significantly. With no placebo group and substantial dropout, this does not prove equivalence or establish an antidepressant effect of L-phenylalanine. 1
The historical signal concerns the DL mixture, not a confirmed benefit of L-phenylalanine. 1
Effects by health goal
Open an effect to see the studies behind its rating. Bars show the size of the effect; the letter grades the evidence.
Cognition4 effects
No study is linked to this rating.
No study is linked to this rating.
Stress & Mood2 effects
No study is linked to this rating.