--- title: Does sleep duration and sleep timing affect reproductive hormones and ovulation? description: Yes, but the effects are modest. For every extra hour of sleep, estradiol increased 3.9% and progesterone increased 9.4%. Less than 7 hours of sleep was linke url: https://niyora.com/research/papers/the-influences-of-sleep-duration-chronotype-and-nightwork-on-the-ovarian-cycle-2020/ --- - [Niyora](https://niyora.com/) - [Research](https://niyora.com/research/) - [Library](https://niyora.com/research/library/) - Does sleep duration and sleep timing affect reproductive hormones and ovulation? Cohort study, 2020 # Does sleep duration and sleep timing affect reproductive hormones and ovulation? Yes, but the effects are modest. For every extra hour of sleep, estradiol increased 3.9% and progesterone increased 9.4%. Less than 7 hours of sleep was linked to earlier hormone peaks, and shift work was linked to lower testosterone. Moderate study design 259 regularly menstruating women, including 77 working night or shift work ## What they did A prospective cohort study (BioCycle Study, 2005-2007) of 259 women followed across 1-2 menstrual cycles. Blood hormone levels were measured up to 8 times per cycle. Women kept sleep diaries recording daily sleep and completed questionnaires about chronotype (morning or evening person) and shift work. ## What they found For every extra hour of daily sleep, mean estradiol increased by 3.9% (95% CI 2.0, 5.9%) and luteal phase progesterone increased by 9.4% (CI 4.0, 15.2%). Less than 7 hours of sleep per day was linked to earlier peaks in several hormones. Women working night or shift work (n=77) had 9.9% lower testosterone than day workers. Women with morning chronotypes (n=47) had earlier estradiol peaks. Sleep duration showed a possible but imprecise protective effect against failure to ovulate. ## What it means for you Sleep affects reproductive hormones, with longer sleep linked to higher estradiol and progesterone. However, these hormonal changes appear small and may not significantly affect ovulation in healthy women. The study only tracked hormone levels, not whether women experienced symptoms. 259 Women followed across cycles 3.9% Estradiol increase per hour of sleep 9.4% Luteal progesterone increase per hour ## About the study Original title The influences of sleep duration, chronotype, and nightwork on the ovarian cycle Authors Michels KA, Mendola P, Schliep KC et al. Journal Chronobiology international Year 2020 Study design Cohort study Participants 77 Open access Yes Read the paper [doi.org/10.1080/07420528.2019.1694938](https://doi.org/10.1080/07420528.2019.1694938) Original abstract Despite research indicating that sleep disorders influence reproductive health, the effects of sleep on reproductive hormone concentrations are poorly characterized. We prospectively followed 259 regularly menstruating women across one to two menstrual cycles (the BioCycle Study, 2005-2007), measuring fasting serum hormone concentrations up to eight times per cycle. Women provided information about daily sleep in diaries and chronotype and night/shift work on a baseline questionnaire. We evaluated percent differences in mean hormone concentrations, the magnitude of shifts in the timing and amplitude of hormone peaks, and the risk for sporadic anovulation associated with self-reported sleep patterns and night/shift work. We estimated chronotype scores - categorizing women below and above the interquartile range (IQR) as "morning" and "evening" chronotypes, respectively. For every hour increase in daily sleep duration, mean estradiol concentrations increased by 3.9% (95% confidence interval [CI] 2.0, 5.9%) and luteal phase progesterone by 9.4% (CI 4.0, 15.2%). Receiving less than 7 hours of sleep per day was associated with slightly earlier rises in peak levels for several hormones. Women reporting night/shift work (n = 77) had lower testosterone relative to women employed without night/shift work (percent difference: -9.9%, CI -18.4, -0.4%). Women with morning chronotypes (n = 47) had earlier rises in estradiol during their cycles and potentially an earlier rise in luteinizing hormone. Compared to those who had intermediate chronotypes, women with evening chronotypes (n = 42) had a later luteinizing hormone peak of borderline statistical significance. A reduced risk for sporadic anovulation was suggested, but imprecise, for increasing hours of daily sleep leading up to ovulation (risk ratio 0.79, CI 0.59, 1.06), while an imprecise increased risk was observed for women with morning chronotypes (risk ratio 2.50, CI 0.93, 6.77). Sleep-related hormonal changes may not greatly alter ovarian function in healthy women, but have the potential to influence gynecologic health. Reproduced under CC-BY. ## Topics [Sleep and insomnia](https://niyora.com/research/topics/symptom-sleep/)[Cognition, concentration and memory](https://niyora.com/research/topics/symptom-cognition/)[Work and productivity](https://niyora.com/research/topics/life-area-work/) Research tells you what helps on average. Niyora helps on the day it hits. Calm down, see it another way, and decide what to say, with a PMS and PMDD app built by a doctor. ## Related studies Survey study, 2025 What behavioral symptoms of premenstrual syndrome are most common? 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