The research behind
Cooldown Nightcap.
Most sleep supplements pick ingredients first and dose them later. We did it the other way around. Cooldown Nightcap is formulated around five compounds whose effects on sleep quality have been documented in peer-reviewed research — at doses that match what those studies used.
Below is the bibliography. Use it. Send it to your doctor. Cross-reference it. We have nothing to hide behind generic claims.
Glycine
3000 mg per sachetThe most-researched amino acid for sleep quality in adults who run hot. Acts through the suprachiasmatic nucleus to support the small overnight drop in core body temperature your body needs to fall into deep sleep. The studied dose is 3 grams taken before bed — exactly what is in every sachet.
Yamadera, W., Inagawa, K., Chiba, S., Bannai, M., Takahashi, M., & Nakayama, K. (2007). Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes. Sleep and Biological Rhythms, 5(2), 126–131.
doi.org/10.1111/j.1479-8425.2007.00262.xBannai, M., & Kawai, N. (2012). New therapeutic strategy for amino acid medicine: Glycine improves the quality of sleep. Journal of Pharmacological Sciences, 118(2), 145–148. (Open access review.)
jstage.jst.go.jp/article/jphs/118/2/118_11R04FMMagnesium Glycinate
200 mg per sachetThe chelated form of magnesium with the highest bioavailability — bound to glycine for absorption that bypasses the digestive sensitivity associated with magnesium oxide or citrate. Magnesium replenishment is broadly studied for sleep quality and muscle relaxation.
Rao, A. et al. (2024). Magnesium Bisglycinate Supplementation in Healthy Adults Reporting Poor Sleep: A Randomized, Placebo-Controlled Trial. Nutrients.
pmc.ncbi.nlm.nih.gov/articles/PMC12412596L-Theanine
200 mg per sachetA natural amino acid found in green tea. Studied for its ability to promote alpha brain wave activity — the calm, alert state that transitions smoothly into sleep without sedation. The studied dose range is 50–200 mg. Cooldown Nightcap uses the upper end.
Nobre, A. C., Rao, A., & Owen, G. N. (2008). L-theanine, a natural constituent in tea, and its effect on mental state. Asia Pacific Journal of Clinical Nutrition, 17 Suppl 1, 167–168.
pubmed.ncbi.nlm.nih.gov — search L-theanine Nobre 2008(2024 review). L-theanine: From tea leaf to trending supplement — does the science match the hype for brain health and relaxation?
pmc.ncbi.nlm.nih.gov/articles/PMC12892352Affron® Saffron
28 mg per sachetA patented standardized extract of saffron (Crocus sativus), studied at the exact dose used in Cooldown Nightcap. In a 28-day randomized controlled trial, 28 mg taken one hour before bed improved sleep quality ratings and increased evening melatonin levels — without affecting cortisol.
Lopresti, A. L., Smith, S. J., Metse, A. P., & Drummond, P. D. (2021). An investigation into an evening intake of a saffron extract (affron®) on sleep quality, cortisol, and melatonin concentrations in adults with poor sleep: a randomised, double-blind, placebo-controlled, multi-dose study. Sleep Medicine, 86, 7–18.
sciencedirect.com — Lopresti 2021 multi-dose studyLopresti, A. L., Smith, S. J., Metse, A. P., & Drummond, P. D. (2020). Effects of saffron on sleep quality in healthy adults with self-reported poor sleep: a randomized, double-blind, placebo-controlled trial. Journal of Clinical Sleep Medicine, 16(6), 937–947.
pubmed.ncbi.nlm.nih.gov/32056539Apigenin
50 mg per sachetA natural flavonoid found in chamomile. Studied for binding to GABA-A receptor benzodiazepine sites — the same calming pathway pharmaceutical anxiolytics use, without the dependence risk. Helps quiet the racing mind that keeps hot sleepers awake.
Avallone, R., Zanoli, P., Puia, G., Kleinschnitz, M., Schreier, P., & Baraldi, M. (2000). Pharmacological profile of apigenin, a flavonoid isolated from Matricaria chamomilla. Biochemical Pharmacology, 59(11), 1387–1394.
pubmed.ncbi.nlm.nih.gov/10751547Zick, S. M., Wright, B. D., Sen, A., & Arnedt, J. T. (2011). Preliminary examination of the efficacy and safety of a standardized chamomile extract for chronic primary insomnia: A randomized placebo-controlled pilot study. BMC Complementary & Alternative Medicine.
pmc.ncbi.nlm.nih.gov/articles/PMC3198755