FemaleLEVOHNCT07759635
The Influence of Plan B® on Cardiovascular Health.
A study testing Plan B (Levonorgestrel) in people with Female and Premenopausal, run by McMaster University at 1 site in Canada.
Trial summary
The goal of this double-blind randomized controlled trial is to learn about the impacts of a single dose of Plan B® on the cardiovascular system in young, health, premenopausal females. The main questions it aims to answer are: 1. What is the short-term affect of Plan B® affect on the venous system? 2. Read more about this study
- Who is it for?
- Ages 18 to 35 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Female, Premenopausal
- What is being tested?
- Plan B (Levonorgestrel)
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 40 participants
- Where
- 1 siteCanada
- Study dates
- 22 Jul 2026to 1 Sep 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 35 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Provide written informed consent.
- Pre-menopausal female.
- 18 - 35 years of age.
- Naturally cycling (i.e., not using any form of hormonal contraception for ≥ 3 months).
- Eumenorrheic (i.e., experiencing a predictable menstrual cycle lasting 21-45 days).
- In the surrounding Hamilton area, or able to visit McMaster for study visits.
- Not pregnant.
Who cannot join
- 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.
- Known or suspected pregnancy.
- At risk of the development of unwanted pregnancy within the past 72 hours.
- Known, suspected, or history of cardiovascular, metabolic, or musculoskeletal disease.
- Undiagnosed abnormal vaginal bleeding.
- 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.
- Active or history of migraine.
- A condition or factor that would prevent the use of Plan B®.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
Vascular Dynamics Lab
Hamilton, Ontario, L8S 4L8
Maureen J MacDonald, PhD, 905-525-9140 ext. 23580, macdonmj@mcmaster.ca
About this study
Official title: The Influence of a Single Dose of Emergency Contraception on Markers of Venous Thrombosis and Vascular Function in Young, Healthy Females.
The goal of this double-blind randomized controlled trial is to learn about the impacts of a single dose of Plan B® on the cardiovascular system in young, health, premenopausal females. The main questions it aims to answer are:
- What is the short-term affect of Plan B® affect on the venous system?
- What is the short-term affect of Plan B® affect on the health of arteries?
Read more
Researchers will compare a single dose of Plan B® (1.5 mg of levonorgestrel) to a placebo to see if Plan B® has unique effects on the cardiovascular system.
Participants will:
- Undergo baseline measurements of venous thrombosis markers, blood pressure, and measures of arterial function using ultrasound.
- Be randomized to either take a Plan B® or placebo pill
- Repeat baseline measurements of venous thrombosis markers, blood pressure, and measures of arterial function using ultrasound each hour, for 6-hours, and then 24- and 48- hours after taking the Plan B® or placebo pill.
- Conditions
- Female, Premenopausal
- Being tested
- Plan B (Levonorgestrel), Placebo (gelatin capsule)
- Keywords
- Emergency contraceptives, Hormonal contraceptives, Venous thrombosis, Endothelial function
- Medical subject headings
- Venous Thrombosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Plan B (Levonorgestrel)Drug
1 x dose of 1.5 mg levonorgestrel tablet over encapsulated to mimic placebo.
Placebo (gelatin capsule)Other
Gelatin capsule over encapsulated to mimic Plan B
| Study group | Role | What they receive |
|---|---|---|
| Plan B® | Experimental | 1.5 mg Levonorgestrel Receives: Drug: Plan B (Levonorgestrel) |
| Placebo | Placebo comparator | Gelatin capsule Receives: Other: Placebo (gelatin capsule) |
What is being measured
The primary outcome is the main question the study is designed to answer.
D-Dimer
Measured in ug/L FEU from platelet poor plasma using the HemosIL® D-Dimer HS 500 assay, a latex immunoturbidimetric assay (LIA) on the ACL TOP analyzer.
Measured: Baseline, 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo
Prothrombin fragment 1+2
Measured in pg/mL from platelet-poor plasma using an enzyme-linked immunosorbent assay (ELISA).
Measured: Baseline, 1-hour, 2-hours, 6-hours, 24-hours, and 48-hours post-ingestion of Plan B/placebo.
Thrombin antithrombin
Measured in pg/mL from platelet-poor plasma using an enzyme-linked immunosorbent assay (ELISA).
Measured: Baseline, 1-hour, 2-hours, 6-hours, 24-hours, and 48-hours post-ingestion of Plan B/placebo.
P-Selectin
Measured in pg/mL from platelet-poor plasma using an enzyme-linked immunosorbent assay (ELISA).
Measured: Baseline, 1-hour, 2-hours, 6-hours, 24-hours, and 48-hours post-ingestion of Plan B/placebo.
Secondary outcomes (9)
Brachial artery flow-mediated dilation
Measured as the percent change in brachial artery diameter from baseline to peak dilation following reactive hyperemia (%FMD).
Measured: Baseline, 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo
Levonorgestrel
Measured in pg/mL from serum using an enzyme-linked immunosorbent assay (ELISA).
Measured: 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo
Systolic blood pressure
Measured in millimeters of mercury (mmHg)
Measured: Baseline, 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo
Diastolic blood pressure
Measured in millimeters of mercury (mmHg)
Measured: Baseline, 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo
Mean arterial pressure
Measured in millimeters of mercury (mmHg)
Measured: Baseline, 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo
Heart rate
Measured in beats per minute (bpm).
Measured: Baseline, 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo
Height
Measured in cm using a standiometer
Measured: Baseline
Weight
Measured in kg using a weight scale
Measured: Baseline
Body mass index
weight (kg) / ( height (m) )^2
Measured: Baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Aug 2026
- Study start22 Jul 2026
- Primary completion1 Jun 2027 (estimated)
- Study completion1 Sep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for FemaleStudies of the same condition, open and under way.
- More trials run by McMaster UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- McMaster University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Mark Crowther, MD, MSc, LLM, FRCPC, FRSC, Principal investigator, McMaster UniversityMaureen J MacDonald, PhD, Principal investigator, McMaster University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07759635
- Sponsor's protocol ID
- LEVOH
- Acronym
- LEVOH
- Status last verified
- May 2026
- First submitted
- 26 May 2026
- Last updated
- 14 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 14 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Influence of a Single Dose of Emergency Contraception on Markers of Venous Thrombosis and Vascular Function in Young, Healthy Females.
- ClinicalTrials.gov ID
- NCT07759635
- Acronym / sponsor ID
- LEVOH / LEVOH
- Conditions
- Female, Premenopausal
- Keywords
- Emergency contraceptives, Hormonal contraceptives, Venous thrombosis, Endothelial function
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- McMaster UniversityUniversity, hospital or other
- Study start
- 22 Jul 2026 (actual)
- Primary completion
- 1 Jun 2027 (estimated)
- Study completion
- 1 Sep 2027 (estimated)
- First posted
- 12 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this double-blind randomized controlled trial is to learn about the impacts of a single dose of Plan B® on the cardiovascular system in young, health, premenopausal females. The main questions it aims to answer are:
- What is the short-term affect of Plan B® affect on the venous system?
- What is the short-term affect of Plan B® affect on the health of arteries?
Researchers will compare a single dose of Plan B® (1.5 mg of levonorgestrel) to a placebo to see if Plan B® has unique effects on the cardiovascular system.
Participants will:
- Undergo baseline measurements of venous thrombosis markers, blood pressure, and measures of arterial function using ultrasound.
- Be randomized to either take a Plan B® or placebo pill
- Repeat baseline measurements of venous thrombosis markers, blood pressure, and measures of arterial function using ultrasound each hour, for 6-hours, and then 24- and 48- hours after taking the Plan B® or placebo pill.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Plan B® | Experimental | Drug: Plan B (Levonorgestrel)1.5 mg Levonorgestrel |
| Placebo | Placebo comparator | Other: Placebo (gelatin capsule)Gelatin capsule |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- Provide written informed consent.
- Pre-menopausal female.
- 18 - 35 years of age.
- Naturally cycling (i.e., not using any form of hormonal contraception for ≥ 3 months).
- Eumenorrheic (i.e., experiencing a predictable menstrual cycle lasting 21-45 days).
Key exclusion criteria (8 listed)
- 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.
- Known or suspected pregnancy.
- At risk of the development of unwanted pregnancy within the past 72 hours.
- Known, suspected, or history of cardiovascular, metabolic, or musculoskeletal disease.
- Undiagnosed abnormal vaginal bleeding.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Plan B (Levonorgestrel)1 x dose of 1.5 mg levonorgestrel tablet over encapsulated to mimic placebo. | Drug | Plan B® |
| Placebo (gelatin capsule)Gelatin capsule over encapsulated to mimic Plan B | Other | Placebo |
Primary outcome
D-Dimer
Time frame: Baseline, 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo
Measured in ug/L FEU from platelet poor plasma using the HemosIL® D-Dimer HS 500 assay, a latex immunoturbidimetric assay (LIA) on the ACL TOP analyzer.
Prothrombin fragment 1+2
Time frame: Baseline, 1-hour, 2-hours, 6-hours, 24-hours, and 48-hours post-ingestion of Plan B/placebo.
Measured in pg/mL from platelet-poor plasma using an enzyme-linked immunosorbent assay (ELISA).
Thrombin antithrombin
Time frame: Baseline, 1-hour, 2-hours, 6-hours, 24-hours, and 48-hours post-ingestion of Plan B/placebo.
Measured in pg/mL from platelet-poor plasma using an enzyme-linked immunosorbent assay (ELISA).
P-Selectin
Time frame: Baseline, 1-hour, 2-hours, 6-hours, 24-hours, and 48-hours post-ingestion of Plan B/placebo.
Measured in pg/mL from platelet-poor plasma using an enzyme-linked immunosorbent assay (ELISA).
9 secondary outcomes
Brachial artery flow-mediated dilation
Time frame: Baseline, 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo
Levonorgestrel
Time frame: 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo
Systolic blood pressure
Time frame: Baseline, 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo
Diastolic blood pressure
Time frame: Baseline, 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo
Mean arterial pressure
Time frame: Baseline, 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo
Heart rate
Time frame: Baseline, 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo
Height
Time frame: Baseline
Weight
Time frame: Baseline
Body mass index
Time frame: Baseline
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Oct 2026.
- Individual participant dataSharing planned: No
Related trials for Female
Recruiting
Methylation Profiling in Self-Samples for Identification of (Epi)Genetic Biomarkers for Gynecological Cancers
Gynaecological Cancers, Ovarian Cancer
RecruitingPhase 1/2
Study of INBRX-106 and INBRX-106 in Combination With Pembrolizumab (Keytruda®) in Subjects With Locally Advanced or Metastatic Solid Tumors (Hexavalent OX40 Agonist)
Solid Tumor, Non-Small Cell Lung Cancer
RecruitingObservational study
Population Pharmacokinetics of Temocillin in Acute Enterobacterial Pyelonephritis in Children
Pyelonephritis
Active, not recruitingPhase 3
A Study of Belzutifan (MK-6482) in Combination With Lenvatinib Versus Cabozantinib for Treatment of Renal Cell Carcinoma (MK-6482-011)
Carcinoma, Renal Cell
Recruiting
Safety and Performance of UCon Patch Electrode
Urinary Incontinence, Urinary Incontinence, Urge
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Mark Crowther, MD, MSc, LLM, FRCPC, FRSC principal investigator
McMaster University
Maureen J MacDonald, PhD principal investigator
McMaster University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Plan B (Levonorgestrel) in people with Female and Premenopausal, run by McMaster University at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 14 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Jenna C Stone, BSc (905-525-9140 ext. 27037, stonej1@mcmaster.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
D-Dimer (time frame: Baseline, 1-hour, 2-hours, 3-hours, 4-hours, 5-hours, 6-hours, 24-hours and 48-hours post-ingestion of Plan B/placebo). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Oct 2026.