Ashwagandha vs Glycine

for sleep

Stronger evidence: tie

Stronger effect: Glycine

Safety: Ashwagandha carries a moderate interaction; Glycine has none recorded.

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

Ashwagandha

grade C low certainty

small, early-stage effect on sleep

Glycine

grade C low certainty

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

3 g before bed, adults
sources: PMID:00000002 · PMID:10000002