Consumer interest in sleep-enhancing supplements has surged alongside increasing concerns about the side effects of traditional sleep medications. Two comprehensive meta-analyses explore how specific supplements affect subjective sleep quality, a key metric in understanding perceived restfulness and ease of sleep onset.

The first study by Chan and Lo (2021) analyzed 31 randomized controlled trials to assess the effectiveness of supplements such as amino acids, melatonin, and vitamin D. The second, by Bent et al. (2006), focused on valerian root, a popular herbal remedy, and included 16 trials with over 1,000 participants.

In the Chan and Lo (2021) review, amino acids, melatonin, and vitamin D significantly improved subjective sleep quality, with melatonin showing a mean difference (MD) of -1.21 and vitamin D an MD of -1.63. However, the heterogeneity was high for both melatonin (I² = 79%) and vitamin D (I² = 85%), indicating variation in study results. Supplements like magnesium, zinc, and resveratrol showed potential but lacked sufficient data for robust conclusions.

Meanwhile, Bent et al. (2006) reported that valerian nearly doubled the chance of improved sleep (relative risk = 1.8, 95% CI: 1.2–2.9) based on dichotomous sleep quality assessments. Importantly, no consistent adverse effects or hangover symptoms were reported, though methodological issues, such as small sample sizes and inconsistent dosing, temper the strength of these findings.

Despite some limitations, these studies suggest a meaningful role for certain supplements in sleep support. Valerian and melatonin, in particular, offer relatively low-risk options for those seeking non-prescription sleep aids.

However, more consistent methodologies and standardized formulations are needed to verify these benefits reliably and to optimize product formulations in consumer gadgets or health tech.