Glycine vs Saffron

for sleep

Stronger evidence: tie

Stronger effect: tie

Safety: No notable interactions recorded for either.

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

grade C low certainty

small trials suggest improved subjective sleep quality and reduced next-day fatigue

3 g before bed, adults

grade C low certainty

small RCTs suggest improved sleep quality

30 mg/day, adults

sources: PMID:10000002 · PMID:41901246