Independent Research
References & Evidence Sources
Primary product, policy and independent health sources used across Yu Sleep Research.
- Yu Sleep — current vendor sales page (pricing, package presentation, guarantee and vendor claims; checked September 2026).
- Yu Sleep refund policy (current 60-day policy and return instructions).
- Yu Sleep shipping policy (delivery and shipping information; wording should be rechecked at checkout because vendor pages contain inconsistent shipping-fee statements).
- NCCIH: Melatonin — What You Need to Know.
- NCCIH: Sleep Disorders and Complementary Health Approaches.
- NIH Office of Dietary Supplements: Dietary Supplement Fact Sheets.
Last updated September 9, 2026