People mainly take Phenylalanine for mood. Based on 12 first-hand reports and 158 meta-analyses & systematic reviews in the medical literature. Ranked #747 of 1,974 overall.
Of reports that state an outcome, 100% are positive.
Of the people who reported each effect, the share who said it got better.
Systematic reviews and meta-analyses from PubMed, with their published conclusions.
3+ meta-analyses or systematic reviews and 10+ randomized controlled trials in humans. The grade measures how much human research exists — read the conclusions below for what it found.
Conclusion: In studies using high-throughput metabolomics, several blood amino acids appear to be consistently associated with the risk of developing type 2 diabetes.
PubMed 27208380 ↗Conclusion: Significantly enriched metabolic pathways were not identified in the remaining biological samples. Whether these metabolites are in the causal pathways or are biomarkers of fetal nutritional deficiency needs to be explored in large, well-phenotyped cohorts.
PubMed 39528475 ↗Conclusion: Our systematic review of human indispensable amino acid and protein requirement research from January 2000 to May 2024 finds limited studies across the lifecycle, particularly in pregnancy, lactation, infancy, childhood, and adolescence.
PubMed 40610129 ↗Conclusion: Further studies over the long term, assessing a range of appetite-regulating hormones and comparing aspartame with other LCS, would be of value. This study was registered in PROSPERO as CRD42024540781 on April 29, 2024.
PubMed 40381807 ↗As stated by users — not a recommendation. Follow the label or your doctor.
How often each side effect came up across all reports.
Verbatim quotes, shortened only — each links to the original discussion.
“caffeine, theanine, alcohol, Phenylalanine, Tyorisine”
“take the tyrosine (or phenylalanine, my favorite) in the morning-midday”
“Caffeine, tyrosine, phenylalanine.”
“Sometimes I add in phenylalanine and mucuna for a boost.”
“upregulate dopamine and increase stores of dopamine with things like uridine monophosphate tyrosine omega 3 fish oils phenylalanine b complex macuna puriens”
User data from public discussions; research from PubMed. Information only, not medical advice — talk to a doctor before starting, stopping or combining anything. Data updated October 2, 2026. How we rate