Calming Amino Acids Compared
Amino acids and related compounds are the second-largest group in our data, led by L-theanine.
| Supplement | Score | Owner comments | Unwanted effects | Calming-effect mentions |
|---|---|---|---|---|
| L-theanine | 4.0 | 330 | 14% | 82 |
| GABA | 3.1 | 40 | 16% | 12 |
| Glycine | 3.0 | 77 | 19% | 17 |
| Taurine | 3.7 | 45 | 7% | 10 |
| NAC (N-acetylcysteine) | 3.2 | 127 | 44% | 4 |
| Inositol | 3.5 | 19 | 0% | 0 |
L-theanine
L-theanine is an amino acid from tea. A 2019 randomized trial gave healthy adults 200 mg a day for 4 weeks and measured stress-related symptoms, and a 2020 review found most studies used 200 to 400 mg a day.[PubMed][PubMed]
GABA
GABA is the brain's main inhibitory neurotransmitter, but it is unclear how much GABA taken by mouth reaches the brain.[PubMed] Owners rate it lower than L-theanine: 3.1 vs 4.0.
NAC
NAC has been studied as an add-on in several psychiatric conditions, including obsessive-compulsive disorder, with mixed results.[PubMed][PubMed] On Reddit it has the highest share of side-effect reports in this group (44%), and 32 rated comments describe feeling flat or numb.
Glycine, taurine and inositol
Glycine studies mostly looked at sleep quality at about 3 g before bed.[PubMed] Taurine research on anxiety is mostly in animals.[PubMed] Inositol trials in panic disorder used large doses of 12 to 18 g a day.[PubMed][PubMed]
Compare: L-theanine vs GABA · glycine vs L-theanine.
You can also compare all rated mood supplements on one page. For quick shortlists by concern, see which calm supplements Reddit owners rate highest. Unsure where to begin? See how to narrow down anxiety supplements.