[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-study-detail:100651343":3},{"organization":4,"armGroups":7,"interventions":20,"overallOfficials":31,"centralContacts":37,"locations":44,"responsibleParty":63,"collaborators":26,"id":65,"slug":66,"hasResults":67,"nctId":68,"briefTitle":69,"officialTitle":70,"acronym":71,"eligibilityCriteria":72,"healthyVolunteers":73,"sex":74,"minAge":75,"maxAge":76,"enrollmentInfo":77,"targetDuration":26,"studyType":80,"phases":81,"briefSummary":83,"conditions":84,"keywords":87,"overallStatus":47,"whyStopped":26,"lastUpdateSubmitDate":92,"lastUpdatePostDateStruct":93,"startDateStruct":96,"completionDateStruct":98,"leadSponsor":100,"locationsCount":101},{"fullName":5,"class":6},"McMaster University","OTHER",[8,14],{"label":9,"type":10,"description":11,"interventionNames":12},"Plan B®","EXPERIMENTAL","1.5 mg Levonorgestrel",[13],"Drug: Plan B (Levonorgestrel)",{"label":15,"type":16,"description":17,"interventionNames":18},"Placebo","PLACEBO_COMPARATOR","Gelatin capsule",[19],"Other: Placebo (gelatin capsule)",[21,27],{"type":22,"name":23,"description":24,"armGroupLabels":25,"otherNames":26},"DRUG","Plan B (Levonorgestrel)","1 x dose of 1.5 mg levonorgestrel tablet over encapsulated to mimic placebo.",[9],null,{"type":6,"name":28,"description":29,"armGroupLabels":30,"otherNames":26},"Placebo (gelatin capsule)","Gelatin capsule over encapsulated to mimic Plan B",[15],[32,35],{"name":33,"affiliation":5,"role":34},"Mark Crowther, MD, MSc, LLM, FRCPC, FRSC","PRINCIPAL_INVESTIGATOR",{"name":36,"affiliation":5,"role":34},"Maureen J MacDonald, PhD",[38],{"name":39,"role":40,"phone":41,"phoneExt":42,"email":43},"Jenna C Stone, BSc","CONTACT","905-525-9140","27037","stonej1@mcmaster.ca",[45],{"facility":46,"status":47,"city":48,"state":49,"zip":50,"country":51,"countryCode":52,"cosmosGeoPoint":53,"geoPoint":58,"contacts":59},"Vascular Dynamics Lab","RECRUITING","Hamilton","Ontario","L8S 4L8","Canada","CA",{"type":54,"coordinates":55},"Point",[56,57],-79.84963,43.25011,{"lat":57,"lon":56},[60],{"name":36,"role":40,"phone":41,"phoneExt":61,"email":62},"23580","macdonmj@mcmaster.ca",{"type":64,"investigatorFullName":26,"investigatorTitle":26,"investigatorAffiliation":26,"oldNameTitle":26,"oldOrganization":26},"SPONSOR","100651343","the-influence-of-plan-b-on-cardiovascular-health-100651343",false,"NCT07759635","The Influence of Plan B® on Cardiovascular Health.","The Influence of a Single Dose of Emergency Contraception on Markers of Venous Thrombosis and Vascular Function in Young, Healthy Females.","LEVOH","Inclusion Criteria:\n\n1. Provide written informed consent.\n2. Pre-menopausal female.\n3. 18 - 35 years of age.\n4. Naturally cycling (i.e., not using any form of hormonal contraception for ≥ 3 months).\n5. Eumenorrheic (i.e., experiencing a predictable menstrual cycle lasting 21-45 days).\n6. In the surrounding Hamilton area, or able to visit McMaster for study visits.\n7. Not pregnant.\n\nExclusion Criteria:\n\n1. 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\u002Fexcipient in the placebo capsule.\n2. Known or suspected pregnancy.\n3. At risk of the development of unwanted pregnancy within the past 72 hours.\n4. Known, suspected, or history of cardiovascular, metabolic, or musculoskeletal disease.\n5. Undiagnosed abnormal vaginal bleeding.\n6. Use of anti-HIV drugs, anticonvulsant drugs, antibiotics, rifampicin\u002Frifabutin, 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.\n7. Active or history of migraine.\n8. A condition or factor that would prevent the use of Plan B®.",true,"FEMALE","18 Years","35 Years",{"count":78,"type":79},40,"ESTIMATED","INTERVENTIONAL",[82],"NA","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:\n\n1. What is the short-term affect of Plan B® affect on the venous system?\n2. What is the short-term affect of Plan B® affect on the health of arteries?\n\nResearchers 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.\n\nParticipants will:\n\n1. Undergo baseline measurements of venous thrombosis markers, blood pressure, and measures of arterial function using ultrasound.\n2. Be randomized to either take a Plan B® or placebo pill\n3. 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.",[85,86],"Female","Premenopausal",[88,89,90,91],"Emergency contraceptives","Hormonal contraceptives","Venous thrombosis","Endothelial function","2026-08-06",{"date":94,"type":95},"2026-08-12","ACTUAL",{"date":97,"type":79},"2026-07-22",{"date":99,"type":79},"2027-09-01",{"name":5,"class":6},1]