Also known as: 5-hydroxytryptophan, griffonia simplicifolia
Latest evidence update: 2026-05-01
Strongest in Consistency (77). Held back by Sample size (18).
Solid mix of RCTs with some methodological gaps.
Some independent replication, statistical precision uneven.
Small combined sample; treat as preliminary.
Studies agree on direction of effect.
Evidence base skews older; field may have moved on.
No per-outcome numbers yet for this one. Each finding's direction and strength is shown in the research below.
Areas where research points to a consistent direction of effect. The strength of evidence is graded; the size of the effect is not quantified.
Recommended: 50-100mg daily
ProtocolEngine provides general health information based on published research. This is not medical advice. Consult a healthcare professional before starting any supplement or health protocol.
May help reduce depression and improve mood in older adults
May improve sleep quality in people with poor sleep patterns
May help reduce body weight and appetite in overweight individuals
May improve motor function and reduce REM sleep behavior symptoms in Parkinson's disease patients
May improve cognitive function in older adults