CaREFREE Study (Calorie Restriction, Environment and Fitness: Reproductive Effects Evaluation Study)
Public ClinicalTrials.gov record NCT02858336. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
Background: Functional hypothalamic amenorrhea (functional HA) is a condition where a woman s period stops for a temporary time. This is due to improper function of the hypothalamus. This is the part of the brain that directs the whole reproductive system. Researchers want to learn more about functional HA. They also want to learn how diet, exercise, and other factors may change women s menstrual cycles. Objective: To better understand functional HA. Eligibility: Healthy women ages 18-28 years old who: * Have regular periods * Exercise no more than 4 hours a week * Had their first period at age 11-14 Design: Participants will be prescreened over the phone. Participants will be screened with: * Blood and urine tests * Medical history * Physical exam. Participants will have 9 or 10 visits over about 3 menstrual cycles. These include: * Repeat of screening tests * Questionnaires * Exercise test * Resting energy expenditure test: Participants fast overnight before the test. They lie on their back under a canopy for a half hour. * Body composition test: This is done with a dual energy x-ray absorptiometry (DXA) scan. * Pelvic ultrasound * For two full-day visits, an IV is inserted into an arm vein. The IV takes a blood sample every 10 minutes for 8 hours. Participants will keep logs: * Menstrual cycle log * Diet log for three 4-day cycles Participants will receive test kits to complete at home: * Daily blood and urine sample * Ovulation Participants will take a daily iron supplement. They will wear a wristband that monitors activity 24 hours a day. Participants will stick to a special diet for two 5-day periods of time. They will complete two 4-day exercise programs.
Study identification
- NCT ID
- NCT02858336
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Not applicable
- Enrollment
- 38 participants
Conditions and interventions
Eligibility (public fields only)
- Age range
- 18 Years to 28 Years
- Sex
- Female
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Jan 11, 2017
- Primary completion
- Jun 28, 2019
- Completion
- Jun 28, 2019
- Last update posted
- Aug 27, 2026
2017 – 2019
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| NIEHS Clinical Research Unit (CRU) | Research Triangle Park | North Carolina | 27709 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT02858336, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Aug 27, 2026 · Synced Sep 6, 2026
Related: full search, browse by condition, browse by drug or therapy, browse by sponsor, browse by U.S. city.
Open the official record
The complete protocol, eligibility criteria, and contact information for NCT02858336 live on ClinicalTrials.gov.