It depends on the case; there is no single guideline.
Observational study (1,936 Italian adults): higher intake of certain dietary polyphenols was associated with better sleep quality. Cross-sectional association (does not prove cause), consistent with the bidirectional relationship between diet and sleep.
View the study (study) →Diet · Highest evidence: Low · 1 finding
Information, not medical advice. Prescription drugs require a doctor.
Information, not medical advice. Scientific evidence reflects the quality of the studies.