营销话术证据 A · 指南级
5-10 mg 褪黑素帮助入睡
真相
0.3 mg 的生理剂量效果相当；5-10 mg 会让受体过载，带来第二天犯困和节律紊乱。
这话术为什么会流行
在美国以大剂量 OTC 出售，迎合“越多越管用”的直觉；多数人不知道有效剂量其实小得多。
机制速览
褪黑素不是把你打晕的安眠药，而是一条消息：天黑了，该准备睡了。平时睡前大约两个小时，脑子深处一个豌豆大的腺体——松果体——开始把它放进血里。
来源（4）
- Brzezinski, A., et al. (2005). Effects of exogenous melatonin on sleep: a meta-analysis. Sleep Medicine Reviews, 9(1), 41–50. 17 studies, 284 subjects: melatonin reduced sleep onset latency by 4.0 min (95% CI 2.5-5.4), increased sleep efficiency by 2.2% (0.2-4.2) and total sleep by 12.8 min (2.9-22.8); in the 15 studies of healthy people or people with insomnia only: 3.9 min, 3.1% and 13.7 min (abstract, PMID 15649737).
- Cajochen, C., Kräuchi, K., & Wirz-Justice, A. (2003). Role of melatonin in the regulation of human circadian rhythms and sleep. Journal of Neuroendocrinology, 15(4), 432-437. Review of endogenous melatonin as the internal signal of biological night: secretion is driven by the suprachiasmatic nucleus and suppressed by light, and the hormone feeds back on the SCN through MT1 and MT2 receptors, with sleep-promoting effects that track its thermoregulatory action rather than a hypnotic one.
- Chang, A. M., Aeschbach, D., Duffy, J. F., & Czeisler, C. A. (2015). Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proceedings of the National Academy of Sciences, 112(4), 1232-1237. In a controlled in-laboratory crossover, reading from a light-emitting eReader for four hours before bed across five consecutive evenings suppressed evening melatonin, delayed circadian timing and sleep onset, reduced REM sleep, and left participants less alert the next morning, compared with reading a printed book. Full text: 12 healthy young adults (6 women), 14-day inpatient randomized crossover; about 4 h of reading before bedtime in otherwise very dim room light on 5 consecutive evenings per condition (the eReader held at 30-50 photopic lux in the angle of gaze; the printed book reflected about 0.9 lux). On night 5 the eReader suppressed evening melatonin by 55.12 ± 20.12% (print book: none); dim-light melatonin onset was more than 1.5 h later (22:31 vs 21:01); sleep latency was nearly 10 min longer (25.65 vs 15.75 min); total sleep time and sleep efficiency did not differ (full text, PMC4313820; abstract, PMID 25535358).
- Lelak, K., Vohra, V., Neuman, M. I., Toce, M. S., & Sethuraman, U. (2022). Pediatric melatonin ingestions — United States, 2012–2021. MMWR Morbidity and Mortality Weekly Report, 71(22), 725–729. National Poison Data System 2012-2021, ages 19 and under: 260,435 pediatric melatonin ingestions, the annual number up 530%; 4.9% of all pediatric ingestions reported in 2021 vs 0.6% in 2012; hospitalizations and serious outcomes rose, mainly from unintentional ingestions in children aged 5 or under; 5 children needed mechanical ventilation and 2 died. US over-the-counter melatonin sales rose from $285 million (2016) to $821 million (2020) (abstract, PMID 35653284).