Plan B and heart health: a look at how a single dose affects veins and arteries in young women

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This is a randomized, double-blind, placebo-controlled trial that evaluates the short-term cardiovascular effects of a single levonorgestrel dose (Plan B®) versus placebo in healthy premenopausal women. Participants will have baseline measurements of venous thrombosis markers, blood pressure, and arterial function via ultrasound, then be assigned to Plan B® or placebo. Measurements will be repeated hourly for 6 hours and again at 24 and 48 hours to assess any transient changes in vascular markers and function. The study is conducted at the Vascular Dynamics Lab in Hamilton, under McMaster University as the lead sponsor.

Why it matters

Who can join: the full rules

Inclusion Criteria:

1. Provide written informed consent.
2. Pre-menopausal female.
3. 18 - 35 years of age.
4. Naturally cycling (i.e., not using any form of hormonal contraception for ≥ 3 months).
5. Eumenorrheic (i.e., experiencing a predictable menstrual cycle lasting 21-45 days).
6. In the surrounding Hamilton area, or able to visit McMaster for study visits.
7. Not pregnant.

Exclusion Criteria:

1. Known hypersensitivity to the active substance levonorgestrel or to any ingredient in this formulation (i.e., levonorgestrel colloidal silicon dioxide, potato starch, magnesium stearate, talc, cornstarch, lactose monohydrate, or any ingredient/excipient in the placebo capsule.
2. Known or suspected pregnancy.
3. At risk of the development of unwanted pregnancy within the past 72 hours.
4. Known, suspected, or history of cardiovascular, metabolic, or musculoskeletal disease.
5. Undiagnosed abnormal vaginal bleeding.
6. Use of anti-HIV drugs, anticonvulsant drugs, antibiotics, rifampicin/rifabutin, ulipristal acetate, Griseofulvin, Hypericum perforatum (St John's wort) or any other drug that may interfere with the normal pharmacokinetic or pharmacodynamic characteristics of the study intervention.
7. Active or history of migraine.
8. A condition or factor that would prevent the use of Plan B®.

Where it's running

• Vascular Dynamics Lab
  Hamilton, Ontario, Canada Recruiting

Study contacts

• Principal investigator: Mark Crowther, MD, MSc, LLM, FRCPC, FRSC — McMaster University
• Study coordinator: Jenna C Stone, BSc
• Email: stonej1@mcmaster.ca
• Phone: 905-525-9140

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Oxytocin in postmenopausal and premenopausal women

  Researchers will test whether cumulative endogenous neurophysin I, a surrogate for oxytocin, differs over a month between premenopausal and postmenopausal women.

  Recruiting University Hospital, Basel, Switzerland · Basel, Canton of Basel-City · NCT07742124

• Probiotic mix to see if it boosts fullness in adults who are overweight or have obesity

  A probiotic supplement is being tested in adults aged 20-70 who are overweight or have obesity to see if it makes them feel fuller and changes gut bacteria harder after 16 weeks, compared with a placebo.

  Recruiting Maastricht University Medical Center · Maastricht, Limburg · NCT07715955

• Fluorocholine PET/MR imaging in breast cancer patients before treatment

  This study tests whether pre-treatment FCH PET/MR imaging markers can help predict breast cancer subtypes and likely outcomes in women.

  Recruiting Taipei Veterans General Hospital, Taiwan · Taipei, Taiwan · NCT07587086

• Age-related facial skin structure in Chinese women measured with line-field confocal OCT

  This project will use a safe, non-invasive imaging method to see how facial skin structure changes with age in Chinese women aged 20 to 70.

  Recruiting ChinaNorm · Shanghai, Shanghai Municipality · NCT07415798

• Transanal versus Transvaginal rectal resection for anterior rectocele

  This project will test two surgical techniques—stapled transanal and stapled transvaginal rectal resection—to see which better relieves obstructed defecation in women with anterior rectocele.

  Recruiting Cairo University · Cairo, Al-Manial, Cairo, Egypt · NCT07375147

• Dostarlimab with cisplatin, etoposide, and radiotherapy for small cell neuroendocrine cervical cancer

  This trial will test whether adding the immunotherapy drug dostarlimab to cisplatin/etoposide chemotherapy plus radiotherapy helps women with small cell neuroendocrine cervical carcinoma stay progression-free longer.

  Recruiting Phase 2 Chang Gung Memorial Hospital · Taoyuan, Taiwan · NCT07336147

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.