How body clocks in young women coordinate across sleep, activity, heart, gut, and menstrual cycles

Confluence of Sleep, Circadian Rhythms, and the Menstrual Cycle on Injury Risk in Women

Observational Stanford University · NCT07459764

This study will try to see how sleep, movement, heart rate, oxygen, gut signals, light exposure, and the menstrual cycle line up in healthy women aged 18–30 over 28 days.

Quick facts

Study typeObservational
Enrollment20 (estimated)
Ages18 Years to 30 Years
SexFemale
SponsorStanford University Academic / other
Locations1 site (Stanford, California)
Trial IDNCT07459764 on ClinicalTrials.gov

What this trial studies

Over 28 days participants wear multiple sensors that continuously record ambient light, sleep, movement, heart rate, oxygen saturation, temperature, lower-limb biomechanics, and gut physiology. Twice during the month participants come to the lab for seven hours of dim-light saliva sampling to measure melatonin, and two blood draws for proteomic profiling are taken during those sessions. Participants also collect daily urine to detect the LH surge and define menstrual phase. The protocol is observational and focuses on correlating peripheral signals with central circadian markers and menstrual timing rather than testing an intervention.

Who should consider this trial

Good fit: Healthy women aged 18–30 with regular 21–35 day menstrual cycles who are not using hormonal birth control and do not have neuromuscular, gut, or circadian sleep disorders are ideal candidates.

Not a fit: People using hormonal birth control, those with irregular cycles, neuromuscular or gut disorders, circadian sleep disorders, or outside the 18–30 age range are unlikely to qualify or benefit directly from the findings.

Why it matters

Potential benefit: If successful, the results could improve understanding of how different body rhythms interact across the menstrual cycle and inform better timing of treatments or lifestyle recommendations for women.

How similar studies have performed: Individual measures such as dim-light melatonin sampling, actigraphy, and proteomics are established methods, but comprehensive continuous multi-sensor mapping across the menstrual cycle is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Regular menstrual cycle (21-35 days)
* 18-30 years old

Exclusion Criteria:

* Neuromuscular or neurodegenerative disease
* Gut disorders
* circadian sleep disorders
* prescription medications affecting sleep
* recovering from physical injury
* taking hormonal birth control

Where this trial is running

Stanford, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Circadian Dysregulationsleepcircadianmenstrualwomen's health
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.