A randomized, double-blind, placebo-controlled, cross-over pilot study to investigate the efficacy of Rest-ZZZ formula in healthy participants with occasional sleeplessness

The purpose of this study was to investigate the safety and efficacy of Rest-ZZZ, a natural sleep supplement, in healthy adults without a diagnosed sleep disorder. This randomized, double-blind, placebo-controlled, cross-over study consisted of three 7-day supplementation periods with either Rest-ZZZ, Diphenhydramine (DPH), or Placebo, with a 7-day washout. Twenty-seven participants were randomized to one of three intervention sequences and the Healthy People Sleep Quality Index (HPSQI), Quality of Life (QoL), and Profile of Mood States (POMS) questionnaires were assessed at the beginning and end of each supplementation period. Rest-ZZZ and Placebo showed improvements in sleep-related QoL (p ≤ 0.044) and total mood disturbance (TMD) (p =  ≤ 0.028). Fatigue–Inertia was reduced by all study products (p ≤ 0.031). DPH did not result in any significant improvements on sleep quality parameters. A subgroup analysis of participants ≤ 45 years found enhanced efficacy of Rest-ZZZ and improvement in sleep-related QoL vs. Placebo (p = 0.007), as well as improvements in sleep duration (p = 0.007), sleep debt (p = 0.011), and sleep-related QoL (p = 0.033). DPH supplementation resulted in significant improvement in only sleep debt (p = 0.038). Rest-ZZZ had a safe hematology and chemistry profile. Rest-ZZZ resulted in restful sleep that generated corresponding improvements in sleep-related QoL and overall mood. Rest-ZZZ is an efficacious sleep supplement with a favorable safety profile, particularly in those aged 25–45 years.