Progestogens

Progestogens bind progesterone receptors, nuclear receptors that switch on progesterone-responsive genes. They turn estrogen-primed endometrium from proliferative to secretory and thin it over time, thicken cervical mucus so sperm cannot pass, and at higher or depot doses suppress LH so ovulation stops. Given with estrogen in HRT they protect the endometrium.

• LevonorgestrelThe same molecule serves daily pills, a single-dose emergency pill and intrauterine systems that last for years.
• MedroxyprogesteroneIts long-acting depot form explains both its convenience and the slow return of fertility after stopping.

• Contraception (pills, intrauterine systems, injections)
• Emergency contraception
• Heavy or abnormal menstrual bleeding
• Endometriosis pain
• Protecting the endometrium during estrogen HRT

• Irregular bleeding, spotting or no periodsKnown for
• Bone density loss with the depot injectionKnown forSerious
• Weight gain
• Headache
• Breast tenderness
• Mood changes and depression
• Acne
• Ectopic pregnancy if pregnancy occursSerious
• Blood clotsSerious
• Nausea

What the class has in common. Each drug's card has its own, and Known for marks what an exam expects you to know.

• Depot injection: bone loss grows with length of use, so its use beyond 2 years needs review.
• Avoid with current or past breast cancer, unexplained vaginal bleeding or severe liver disease.
• Enzyme inducers such as rifampicin, efavirenz and some antiepileptics can make levonorgestrel fail.
• If pregnancy occurs on a progestogen-only method, rule out ectopic pregnancy.

Written for biofideX in plain words, after checking these references:

• Levonorgestrel intrauterine system (8-year): label (DailyMed)
• Medroxyprogesterone acetate injection: label (DailyMed)
• Medroxyprogesterone acetate tablets: label (DailyMed)
• Levonorgestrel (NCI Thesaurus)
• Emergency contraception (WHO)
• Side effects and risks of the contraceptive injection (NHS)

For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.