5-HTP vs Probiotics

for mood

Stronger evidence: tie

Stronger effect: Probiotics

Safety: 5-HTP carries a serious interaction; Probiotics has none recorded.

For mood, the two are evidence-matched; the difference is in effect and safety.

5-HTP

grade C low certainty

preliminary antidepressant signal; small, lower-quality studies

Probiotics

grade C low certainty

small effects on mood/anxiety in some "psychobiotic" trials; strain-specific, heterogeneous

strain-dependent, adults
sources: PMID:00000035 · PMID:42221774