Progestin-only hormonal methods (mini-pills, implants, and shots)


Oral contraception

Generic Name Brand Name
progestin-only pills Micronor, Nor-QD, Ovrette


Generic Name Brand Name
etonogestrel Implanon


Generic Name Brand Name
medroxyprogesterone acetate Depo-Provera

For information on combination birth control pills, see Birth control pills, patch, or ring.

How It Works

Progestin -only birth control methods, including pills (called "mini-pills"), implants, and shots, prevent the ovaries from releasing an egg (ovulation), thicken mucus at the cervix so sperm cannot enter the uterus, and in rare cases, prevent a fertilized egg from implanting in the uterus.

Birth control mini-pills

Progestin-only mini-pills come in a monthly pack. To be effective, the pills must be taken at the same time each day.

  • If you take a pill more than 3 hours late, use another method of birth control for the next 48 hours to prevent pregnancy. Consider using emergency contraception if you have had sex in the past 3 to 5 days.1
  • If you forget to take a pill for even one day, you must use a second method of birth control until your next period to prevent pregnancy.2 You can't take extra mini-pills (as with combination pills) to make up for a missed day.


The progestin-only implant (Implanon) releases hormones that prevent pregnancy for 3 years. The actual implant is a thin rod about the size of a matchstick. This is inserted under the skin on the inside of the upper arm.

  • The implant is a highly effective method of birth control.
  • The implant must be inserted and removed by a trained health professional.


One injection of Depo-Provera is effective for 12 to 13 weeks.

Why It Is Used

Progestin-only mini-pills, implants, and shots are good choices for women who:

  • Are breast-feeding. The mini-pill is a good choice for breast-feeding mothers. It is very low-dose and does not affect the milk supply. Breast-feeding further reduces the chance of pregnancy.
  • Need short- or long-term birth control that can be stopped at any time. (But it may take from 12 weeks to 18 months to become pregnant after a Depo-Provera injection.)
  • Prefer a form of birth control that does not interfere with sexual spontaneity.
  • Cannot take estrogen, including those who smoke and are older than 35; have long-standing, poorly controlled diabetes; have heart disease; have problems with blood clots; or have high blood pressure.
  • Have migraine headaches with auras, or women whose migraines get worse when taking the estrogen in combination birth control pills.
  • Have heavy, painful menstrual periods. Progestin reduces heavy bleeding and cramping.
  • Have anemia from heavy menstrual bleeding.
  • Have sickle cell disease. Women with sickle cell disease may have fewer problems from their disease when using the Depo-Provera shot.

How Well It Works

Shots and implants are highly effective methods of birth control.

Progestin-only mini-pills are very effective, but combination hormone pills are even more effective. Also, the mini-pill has to be taken at the same time every day to work correctly.

Depo-Provera shot

This method is highly effective, unless you fail to get a shot after 3 months.3

  • Typical use: Among all Depo-Provera users, 3 women out of 100 become pregnant each year.
  • Perfect use: Of women who get their shots on schedule, only 3 out of 1,000 become pregnant each year.

Progestin mini-pill

This method is very effective, but you must take the mini-pill at the same time every day.3

  • Typical use: Among all mini-pill users, 8 women out of 100 become pregnant each year.
  • Perfect use: Of women who take every mini-pill on schedule, only 3 out of 1,000 become pregnant each year.


This method is extremely effective and lasts for 3 years.4

  • Typical use and perfect use are the same for this method, with no reported pregnancies from studies.

Medicines that can interfere with hormonal birth control

Some combinations of medicine may affect the birth control hormones in your body, making them too strong or too weak. This may increase your chance of becoming pregnant. Or a new medicine may be less likely to work because you have birth control hormones in your body. Talk with your doctor or pharmacist to make sure that the medicines you take are not causing problems when you are using hormonal birth control.

Side Effects

Most side effects of the progestin-only birth control methods go away after the first few months of use. Side effects include:

  • Irregular menstrual cycles.
  • Spotting or bleeding between menstrual periods.
  • Sore breasts.
  • Headache.
  • Nausea.
  • Dizziness.
  • Bloating or weight gain, especially with the Depo-Provera shot (to manage this, increase your activity level).4, 1
  • No menstrual periods. Although mini-pill use can stop periods, the shot is most likely to do so. After 1 year, 25% of women taking Depo-Provera shots stop having monthly periods. After 5 years of shots, 80% of women do not have periods.4

Less common progestin side effects include depression and darkening of the skin on the upper lip, under the eyes, or on the forehead (chloasma).

Depo-Provera risks

Bone thinning. Depo-Provera use for 2 or more years can cause bone loss, which may not be fully reversible after stopping the medicine.5

For teens, bone loss from Depo-Provera is a concern. Teens are normally building bone mass as they grow. This is why it is very important for teens to get enough calcium and vitamin D when using Depo-Provera. A small study among teens showed that bone loss from Depo-Provera was reversed after the teens stopped getting the shots.6 Talk to your doctor about your risk if you have been using Depo-Provera for longer than 2 years.

Infection risk. One recent study has shown that Depo-Provera use may make chlamydia or gonorrhea infection more likely if you are exposed to these bacteria.7 If you have any risk of being exposed to sexually transmitted diseases, use condoms.

Progestin risk after having gestational diabetes

Breast-feeding women can use the mini-pill or shot without worrying about effects on their milk supply or the baby. But using progestin-only birth control after having gestational diabetes appears to make it more likely that you will develop diabetes.8, 9 (Combination estrogen-progestin birth control does not appear to increase this diabetes risk.10)

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Progestin-only mini-pills may not be as effective if you are vomiting or have diarrhea. Use another method of birth control for 7 days after vomiting or diarrhea, even if you have not missed any pills.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.



  1. Zieman M, et al. (2007). Managing Contraception for Your Pocket. Tiger, GA: Bridging the Gap Foundation.
  2. Greydanus DE, et al. (2001). Contraception in the adolescent: An update. Pediatrics, 107(3): 562–573.
  3. Trussell J (2004). The essentials of contraception: Efficacy, safety, and personal considerations. In RA Hatcher et al., eds., Contraceptive Technology, 18th ed., pp. 221–252. New York: Ardent Media.
  4. Hatcher RA (2004). Depo-Provera injections, implants, and progestin-only pills (minipills). In RA Hatcher et al., eds., Contraceptive Technology, 18th ed., pp. 461–494. New York: Ardent Media.
  5. U.S. Food and Drug Administration (2004). Black box warning added concerning long-term use of Depo-Provera contraceptive injection. FDA Talk Paper No. T04-50. Available online:
  6. Scholes D, et al. (2005). Change in bone mineral density among adolescent women using and discontinuing depot medroxyprogesterone acetate contraception. Archives of Pediatrics and Adolescent Medicine, 159(2): 139–144.
  7. Morrison CS, et al. (2004). Hormonal contraceptive use, cervical ectopy, and the acquisition of cervical infections. Sexually Transmitted Diseases, 31(9): 561–567.
  8. Kjos SL, et al. (1998). Contraception and the risk of type 2 diabetes mellitus in Latina women with prior gestational diabetes mellitus. JAMA, 280(6): 533–538.
  9. Kahn HS, et al. (2003). Effects of injectable or implantable progestin-only contraceptives on insulin-glucose metabolism and diabetes risk. Diabetes Care, 26(1): 216–225.
  10. Hatcher RA, Nelson A (2004). Combined hormonal contraceptive methods. In RA Hatcher et al., eds., Contraceptive Technology, 18th ed., pp. 391–460. New York: Ardent Media.

Last Updated: May 22, 2008

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