Progestogens — progesterone derivatives
ATC code: G03DA04 (Progesterone, micronized)
Brand names
Prometrium, Crinone, Endometrin
Bio-identical analogue of endogenous progesterone. Binds progesterone receptors in endometrium, myometrium, breast, and CNS. Suppresses endometrial proliferation and stimulates secretory transformation. Through the hepatic metabolite allopregnanolone, exerts anxiolytic and sedative effects — hence oral capsules are taken at bedtime. Oral capsules (Utrogestan, Prajisan) and vaginal forms exist; the vaginal route is often preferable for bioavailability and tolerability.
First line
First-line for endometrial protection during estrogen MHT per NAMS 2022, IMS 2016, BMS 2024. A progestogen is mandatory in women with an intact uterus. Compared with synthetic progestins, micronized progesterone has a more favorable profile for breast cancer risk and thromboembolism. Dose 100–200 mg at bedtime, cyclically (12–14 days per month) or continuously.
First line
Standard for luteal phase support in ART per 2019. Vaginal forms 200 mg three times daily from embryo transfer day until 8–12 weeks of pregnancy. Cochrane meta-analyses favor the vaginal route over oral and find it comparable to IM injectable.
First line
In women with an intact uterus on MHT, micronized progesterone provides endometrial protection and offers mild anxiolytic and sleep-promoting effects, often welcomed by patients. French E3N and EPIC data suggest lower breast cancer risk with micronized progesterone in MHT versus synthetic progestins.
As part of MHT combined with estrogens, in women with a uterus.
Individual decision
Progesterone for threatened miscarriage in patients with confirmed fetal heartbeat is debated. The PRISM trial (NEJM 2019, over 4,100 patients) in women with threatened miscarriage and recurrent loss showed a small benefit of vaginal progesterone 400 mg twice daily – a 3 % absolute increase in live birth (70 % → 73 %). No significant effect in patients without recurrent loss. NG126 2021 supports use in this narrow subgroup. In most patients, the cause is embryonic chromosomal abnormality, and progesterone does not help in that scenario.
The drug is promoted for these uses outside international guidelines. Each entry below is analyzed against AEMPS, FDA, EMA, Cochrane and major RCTs.
Not recommended
Micronised progesterone is a form of the hormone used in reproductive medicine for well-defined indications, such as luteal-phase support during IVF. In alternative and off-protocol approaches it gets promoted more broadly – as a remedy for any infertility, for anti-ageing, or for general hormonal balancing. No convincing benefit has been shown for these expanded uses, and there is no solid evidence behind them. For a specific problem with conception or the menstrual cycle, the right approach is worked out with a gynaecologist after assessment, not through a one-size-fits-all regimen.
Opens the checker prefilled with this drug. Pick the second one from your regimen.
Use in pregnancy (luteal support in ART, prevention of preterm birth with short cervix) is evidence-based. Routine progesterone use in pregnancy without specific indication is not recommended.
An endogenous hormone present in milk in small amounts. Compatible with breastfeeding.
Reference information, not a clinical decision. Discuss feeding pauses or changes with your physician or an IBCLC.
Progesterone, micronized is evaluated for the following indications with varying evidence strength: Endometrial protection during estrogen MHT (evidence tier A), Luteal phase support in ART (evidence tier A), Menopausal symptoms (evidence tier A). See the full indication matrix with dosing and citations above on this page.
Common side effects of Progesterone, micronized (≥ 1 in 100): Drowsiness, dizziness (after oral capsules), Breast tenderness, Mood swings, Nausea, Bloating, Menstrual disturbance. See the Safety section for uncommon and serious reactions.
FDA category B. Use in pregnancy (luteal support in ART, prevention of preterm birth with short cervix) is evidence-based. Routine progesterone use in pregnancy without specific indication is not recommended.
An endogenous hormone present in milk in small amounts. Compatible with breastfeeding.
Progesterone, micronized is contraindicated in: Hypersensitivity; Undiagnosed vaginal bleeding; Severe hepatic impairment; Thrombophlebitis, thromboembolic conditions; Hormone-dependent tumors (relative). Full list in the Safety section.