Birth control pill vs. vaginal ring: which is better for your bones?
NCT ID NCT02367846
First seen Jul 06, 2026 · Last updated Jul 07, 2026 · Updated 1 time
Summary
This study compares the effects of oral contraceptive pills and a contraceptive vaginal ring on bone turnover in young, exercising women aged 18-25. Using a special calcium tracer, researchers measure how each method changes bone calcium balance over 49 days. The goal is to understand whether the route of hormone delivery influences bone health, which could guide contraceptive choices for active women.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- ethinyl estradiol (combined oral contraceptive and contraceptive vaginal ring)
- What this could lead to
- If it works, this could help women choose a contraceptive method that minimizes bone loss, especially for those at risk of osteoporosis.
- What could go wrong
- This is a very small early-phase study with only 6 participants, so results may not apply to all women. The intervention is short-term, and long-term bone effects remain unknown.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
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Phase 4
Runs after approval, following long-term safety and how well the treatment works in everyday use.
- Participants
-
6 people
The number who actually took part.
- Started
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Jan 2015
- Expected to finish
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Dec 2028
An estimate. End dates often move.
- Lead sponsor
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Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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18 to 25 years
- Sex
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Female participants only
- Healthy volunteers
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Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: 1. Female 2. Age 18-25 yrs 3. BMI 18-29 kg/m2 4. Non-smoking 5. Willing to refrain from using hormonal contraceptives for the equilibration + baseline period of the study (\~150 days) 6. Availability to frequently visit the laboratory in the next 12 months 7. Not currently pregnant nor intending to become pregnant in the next 12 months 8. Not lactating 9. No apparent metabolic, endocrine, musculoskeletal, or severe psychiatric disease 10. Willing to maintain consistent exercise (aerobic, weight-bearing) and dietary habits during pre-intervention and intervention periods 11. Willing to refrain from supplements other than those provided by study staff in the next 12 months 12. Variable physical activity acceptable, but mode must be primarily weight bearing 13. At least 9 menses in the past 12 months Exclusion Criteria: 1. Non-weight bearing exercise as primary mode of physical activity 2. Resistance exercise training (≥ 2 times 30 minutes per week of resistance exercise) 3. Complete seasonal change of impact mode of physical activity 4. Known or suspected metabolic or endocrine disease 5. Smoking 6. Pregnant 7. Currently consuming large amounts of soy products 8. Current clinical eating disorder or other axis 1 psychiatric disorder or bipolar disorders 9. Oral or hormonal contraceptive use in the last 6 months 10. Hyperparathyroidism 11. Liver or renal disease 12. Evidence of malabsorption or skeletal disorder 13. Thyroid abnormalities (controlled hypothyroidism acceptable) 14. Chronic use of non-steroidal anti-inflammatory drugs (NSAIDS) 15. Taking medications known to have interactions with oral or vaginal contraceptive therapy 16. Other Exclusion Criteria proposed by the World Health Organization COC Contraindications (Grossman et al., 2011).
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Genom att skicka in godkänner du våra Användarvillkor
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
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Women's Health and Exercise Laboratories, The Pennsylvania State University
University Park, Pennsylvania, 16802, United States