[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › Progestogens (progestins)

# Progestogens (progestins)

Progesterone and synthetic relatives. They protect the uterine lining during estrogen therapy, treat bleeding disorders and prevent pregnancy.

Updated Nov 1, 2026

## What they are

Natural progesterone and synthetic progestins (derivatives of progesterone, such as medroxyprogesterone acetate, or of 19-nortestosterone, such as norethisterone and levonorgestrel). They are used in menopausal hormone therapy for women with a uterus, for secondary amenorrhoea, abnormal uterine bleeding and endometriosis, and as contraceptives (pills, injections, implants, intrauterine systems). Some have androgenic, glucocorticoid or antimineralocorticoid side effects depending on the molecule.

## Mechanism of action

They bind the progesterone receptor, a nuclear receptor, in the uterus, breast, cervix and hypothalamus-pituitary. In the endometrium they turn the estrogen-primed proliferative lining into a secretory one and limit its growth, so unopposed estrogen no longer drives hyperplasia or cancer; withdrawal causes a bleed. At the hypothalamus and pituitary they cut LH and FSH secretion and block ovulation, and they thicken cervical mucus.

Target: Progesterone receptor (PGR), a nuclear receptor

## Key points

- A woman with a uterus who takes estrogen needs a progestogen to prevent endometrial hyperplasia and cancer.
- Combined estrogen-progestin therapy raised the risk of breast cancer, stroke, heart attack and venous thromboembolism in the Women's Health Initiative.
- Depot medroxyprogesterone acetate lowers bone mineral density and fertility may take time to return after it is stopped.
- A progestin withdrawal bleed confirms an estrogen-primed endometrium in the work-up of secondary amenorrhoea.
- Oral micronised progesterone capsules contain peanut oil and cause drowsiness, so they are taken at bedtime.

## Drugs in this class

- [**Medroxyprogesterone acetate** A synthetic progestin: a contraceptive injection every three months, and tablets for bleeding disorders and to protect… Progesterone receptor (PR), a nuclear receptor](https://durgical.com/en/pharmacology/medroxyprogesterone-acetate/)
- [**Norethisterone** A 19-nortestosterone progestin used for endometriosis, abnormal bleeding and amenorrhoea, in contraceptive pills and… Progesterone receptor (PR), a nuclear receptor](https://durgical.com/en/pharmacology/norethisterone/)
- [**Progesterone** The natural ovarian hormone, as oral capsules, used with estrogen to protect the uterus after menopause and to bring… Progesterone receptor (PR), a nuclear receptor](https://durgical.com/en/pharmacology/progesterone/)
- [**Megestrol** A synthetic progestogen taken by mouth. It treats some breast and endometrial cancers and stimulates appetite in… Progesterone receptor (PGR); it also has glucocorticoid activity](https://durgical.com/en/pharmacology/megestrol/)

## Others in the class

- Levonorgestrel
- Desogestrel
- Etonogestrel
- Dienogest
- Drospirenone
- Megestrol acetate

## Test yourself

Think of the answer, then tap the question to see it.

## Why is a progestogen added to estrogen in a woman with a uterus?

Estrogen alone stimulates the endometrium and raises the risk of hyperplasia and endometrial cancer; the progestogen makes the lining secretory and limits its growth.

## How do progestin-only contraceptives prevent pregnancy?

They suppress LH and FSH and so ovulation (strongly with the depot injection), thicken cervical mucus and thin the endometrium.

## What bone effect is linked to depot medroxyprogesterone acetate?

Loss of bone mineral density that increases with duration and may not fully recover.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/classes/progestogens/)

[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

[← All of pharmacology](https://durgical.com/en/pharmacology/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [DailyMed - MEDROXYPROGESTERONE ACETATE tablet](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=9eb200b0-db96-4a51-87ea-04db862978c8) (DailyMed (U.S. National Library of Medicine), 2026); [DailyMed - PROGESTERONE capsule](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=7d73f08d-2de7-44b6-9e44-2d488fe02517) (DailyMed (U.S. National Library of Medicine), 2026); [DailyMed - MEDROXYPROGESTERONE ACETATE injection, suspension](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6457d70a-2f25-4935-8511-726d988f7a03) (DailyMed (U.S. National Library of Medicine), 2026).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

---
Source: https://durgical.com/en/pharmacology/classes/progestogens/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/classes/progestogens/