2013-cajochen.pdf: “Evidence that the Lunar Cycle Influences Human Sleep”, Christian Cajochen, Songül Altanay-Ekici, Mirjam Münch, Sylvia Frey, Vera Knoblauch, Anna Wirz-Justice
“Lunar cycle effects on sleep and the file drawer problem”, (2014-06-16):
Popular beliefs about the influence of the full moon on humans exist, although no solid evidence has so far confirmed these ideas . Cajochen et al.  recently presented fascinating data on lunar cycle effects on human sleep. However, in a re-analysis of sleep electroencephalography (EEG) data in three large samples, we were unable to replicate their findings. In addition, we identified further mostly unpublished null findings, suggesting that the conflicting results might be an example of a publication bias (ie., the file drawer problem).
“Effects of lunar phase on sleep in men and women in Surrey”, (2015-06-12):
Recently, evidence has emerged that the phases of the moon may modulate subjective sleep quality and polysomnographically assessed sleep structure in humans. We aimed to explore further the putative effects of circa-lunar periodicity (~29.5 days) on subjective and objective parameters of human sleep in a retrospective analysis. The baseline sleep recordings of 205 (91 males and 114 females; mean age = 47.47 years, standard deviation = 19.01; range: 20–84 years) healthy and carefully screened participants who participated in two clinical trials in the Surrey Clinical Research Centre were included in the analyses. Sleep was recorded in windowless sleep laboratories. For each study night, we calculated the distance, in days, to the date of the closest full moon phase and based on this distance, classified sleep records in three lunar classes. Univariate analysis of variance with factors lunar class, age and sex was applied to each of 21 sleep parameters. No statistically-significant main effect for the factor lunar class was observed for any of the objective sleep parameters and subjective sleep quality but some statistically-significant interactions were observed. The interaction between lunar class and sex was statistically-significant for total sleep time, Stage 4 sleep and rapid eye movement (REM) sleep. Separate analyses for men and women indicated that in women total sleep time, Stage 4 sleep and REM sleep were reduced when sleep occurred close to full moon, whereas in men REM duration increased around full moon. These data provide limited evidence for an effect of lunar phase on human sleep.
Various human biological functions adhere to a circadian rhythm that to some extent may be affected by environmental factors, including light and temperature . Recent evidence from Cajochen et al.  indicates that human sleep is influenced by the cycle of the moon, measured in conditions precluding the potential impact of nocturnal lunar illumination Here in a similarly retrospective study of 47 healthy volunteers (mean age 23.3, S.D. ±2.9 years) we demonstrate that total sleep time decreases by 25 minutes and cortical reactivity to environmental stimuli during sleep increases around full moon, and rapid eye movement (REM) sleep latency lengthens by 30 minutes around new moon. The findings strengthen the notion that human sleep is modulated by lunar phase but point to important deviations from the study of Cajochen et al. that need to be addressed, particularly with regard to individual susceptibility.