Progestin-Only Contraceptives
Reviewed by: HU Medical Review Board | Last reviewed: March 2023
Progestin-only contraceptives are drugs that contain synthetic progesterone. This is a hormone that influences the female reproductive system. They are used to treat:1-4
- Painful periods
- Endometriosis-related pelvic pain
- Menstrual migraines
- PMS (premenstrual syndrome)
- Menstrual cycle irregularities
A laparoscopy is the only method of definitively diagnosing endometriosis. Because of this, some doctors may treat endometriosis-related symptoms empirically. This means they base their treatment decisions on past experiences and other cases they have seen. If a person has clear signs of endometriosis, their doctor may recommend a progestin-only contraceptive for their pain instead of pursuing diagnostic surgery to see if the pain responds. This may reduce symptoms and pain without the need for surgery.5
In some cases, a person may have signs of endometriosis while also wanting to try birth control. Their doctor may recommend a progestin-only contraceptive to address both issues.5
Progestin-only contraceptives include:4
- Progestin-only birth control pills
- Hormonal IUD (intrauterine device, Mirena)
- Birth control arm implant (Nexplanon)
- Progestin injection (also referred to as the birth control shot, Depo-Provera)
What are the ingredients in progestin-only contraceptives?
Each progestin-only contraceptive contains a synthetically created progestin hormone. The exact version may vary between types. However, they all work in similarly and behave like progesterone naturally produced in the body.2-4
How do progestin-only contraceptives work?
These drugs affect the levels of progesterone in the body. While this hormone is synthetically created in these drugs, the body recognizes it in the same manner.
Progestin-only contraceptives decrease the chances of ovulation. This is the process by which the ovaries release an egg each month. Suppressing ovulation helps stabilize natural hormone levels in the body. In turn, this suppresses endometriosis lesion growth. The progestin in these drugs also thickens cervical mucus. This limits sperm mobility and their ability to reach any eggs that may have been released. Progestin-only contraceptives may lighten the menstrual cycle and reduce pain during a person's period.2-4
All of these methods also suppress the growth of endometriosis lesions and shedding in other parts of the body. This reduces endometriosis-related pain.2-4
Progestin-only contraceptives are not as effective in preventing pregnancy as combination contraceptives (which contain both estrogen and progestin). However, progestin-only drugs may be the only hormonal birth control option for people who cannot take estrogen. This includes those who are currently breastfeeding or who have a history of blood clots.2-4
What are the possible side effects of progestin-only contraceptives?
The most common side effects include:4,6,7
- Unexpected bleeding or spotting
- Changes in menstrual bleeding
- Nausea
- Breast tenderness
- Headaches
- Weight changes
- Dizziness
- Abdominal pain
- Anxiety
- Acne
- Changes in sex drive
Progestin-only drugs may increase the risk of developing certain cancers, such as breast cancer.1-4
These are not all the possible side effects of progestin-only contraceptives. Talk to your doctor about what to expect or if you experience any changes that concern you during treatment with progestin-only contraceptives.
Things to know about progestin-only contraceptives
These drugs may increase a person's risk of serious side effects, including:
- Ovarian cysts
- Ectopic pregnancy (pregnancy outside of the womb)
- Blood clots
- Heart problems
- Liver problems
- Breast cancer or other cancers within the female reproductive system.
People taking progestin-only contraceptives may experience a decrease in bone mineral density, especially when using the birth control shot.4,6,7
Before taking progestin-only contraceptives, tell your doctor if you have:4,6,7
- A personal or family history of blood clots
- Liver conditions
- A personal or family history of breast cancer or cancers of the female reproductive system
- Heart conditions
- Are a smoker
- Are allergic to any drugs or ingredients in any drugs
- Could be pregnant
- Have diabetes or are pre-diabetic
Before beginning treatment for endometriosis, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs.