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Emergency contraception during tirzepatide initiation in an oral contraceptive user — DFSRH MCQ

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HardGLP-1 AgonistsEmergency contraception during tirzepatide initiation in an oral contraceptive userDFSRH

A 31-year-old woman with a BMI of 32 kg/m² has been amenorrhoeic while using a desogestrel 75 microgram progestogen-only pill. She has taken every pill within its permitted window. Eighteen days ago, she switched directly from weekly semaglutide to tirzepatide 2.5 mg weekly for weight management. She was not advised to use additional contraception. She has had no vomiting or diarrhoea. She had condomless intercourse 98 hours ago, with no other intercourse during the preceding 3 weeks. A high-sensitivity urine pregnancy test is negative today. She has low risk of sexually transmitted infection, no contraindication to intrauterine contraception and would accept a copper intrauterine device as ongoing contraception. Which is the most appropriate management plan?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Insert a copper intrauterine device now for emergency and ongoing contraception, then discontinue desogestrel

Explanation lettering: E = shown as A · D = shown as B · B = shown as C · C = shown as D · A = shown as E

Tirzepatide is the GLP-1/GIP agonist for which a clinically important reduction in oral contraceptive bioavailability has been identified. FSRH advises additional barrier contraception or a switch to a non-oral method for 4 weeks after starting tirzepatide, including when switching from another GLP-1 agonist. Correct pill-taking and absence of gastrointestinal symptoms therefore do not remove the pregnancy risk in this case. The copper IUD is the most effective emergency contraceptive, can be inserted within 5 days of this intercourse, is unaffected by body weight, drug interactions or delayed gastric emptying, and immediately supplies her preferred ongoing non-oral contraception. A is incorrect because the intercourse occurred during the 4-week period in which the oral method should not have been relied upon alone. B uses an inadequate levonorgestrel dose for BMI above 26 kg/m² and LNG-EC is unlikely to be effective beyond 96 hours. C corrects the dose for BMI but not the adverse timing at 98 hours; efficacy of double-dose LNG-EC is also unproven. D is the most plausible oral alternative because ulipristal is effective up to 120 hours, but recent progestogen exposure may reduce its effect and the impact of GLP-1 therapy on oral emergency contraception is unknown. It is therefore inferior when an acceptable copper IUD can provide the most effective emergency and ongoing contraception.

Reference: FSRH statement: Glucagon-like peptide-1 agonists and oral contraception (January 2025) — https://www.fsrh.org/Common/Uploaded%20files/documents/CEU-statement-GLP-1-agonists-and-contraception.pdf FSRH Guideline: Emergency Contraception (March 2017, amended April 2026) — https://www.fsrh.org/Common/Uploaded%20files/documents/fsrh-guideline-emergency-contraception03dec2020-amendedjuly2023-11jul.pdf Mounjaro KwikPen 5 mg solution for injection: Summary of Product Characteristics (16 April 2026) — https://www.medicines.org.uk/emc/product/15482/smpc