Types of Birth Control Shots

Depo-Provera Shots

Depo-Provera (also known as DMPA or a Depo shot) is the brand name for medroxyprogesterone acetate. It belongs to a group of drugs called progestins, which are synthetic versions of the hormone progesterone.

Depo-Provera is 99% effective at preventing pregnancy if taken as directed, but its real-world efficacy is around 94%.

Each Depo-Provera injection lasts for around 12 weeks, so you'll need another shot every three months.

There are two versions currently available in the U.S.:

• Depo-Provera: The standard formulation given by an injection into a large muscle of the shoulder or buttocks
• Depo-SubQ Provera: A newer formulation given by injection under the skin of the abdomen or thigh

In addition to preventing pregnancy, Depo-SubQ Provera is approved to treat endometriosis.

Medroxyprogesterone acetate is also available as a pill under the name Provera. It is approved to treat secondary amenorrhea (abnormal cessation of menstruation), abnormal uterine bleeding due to a hormonal imbalance (not due to fibroids or uterine cancer), and endometrial hyperplasia (thickening of the uterine lining).

Depo-Provera shots carry a boxed warning-the most severe label warning issued by the FDA—telling consumers about the risk of significant and often irreversible bone mineral loss with long-term use.

Depo-Provera shots are also associated with an increased risk of breast cancer and should not be used in people with known or suspected breast malignancy.

Noristerat

Noristerat is the brand name for norethisterone enanthate, also known as norethindrone enanthate. It is another progestin-only injectable contraceptive and was introduced shortly before Depo-Provera in 1957.

Norethisterone enanthate is also sold under the brand names Doryxas, Norigest, Nur-Isterate, Syngestal, and Unidepo.

Noristerat is included on the World Health Organization's List of Essential Medicines. While it is not available in the United States, Noristerat is widely used in the United Kingdom, Latin America, Africa, and parts of Europe.

Noristerat is considered safe and has similar efficacy and side effects as Depo-Provera shots. Noristerat is also given by injection into the muscle of the shoulder or buttocks.

Noristrat only provides pregnancy protection for about eight weeks. This means that you need to have a shot every two months, making it less convenient than other injectables.

However, a possible benefit of the shorter protection period is that people who use Noristrat are able to return to fertility faster once they stop treatment, often within three months.

Combined Injectable Contraceptives

Combined injectable contraceptives (CICs) have both progestin and a synthetic form of estrogen called estradiol in them. These are the same hormones that are used in combination birth control pills, the birth control patch, and the NuvaRing.

CICs are not approved in the United States. They are mainly available in Africa, Asia, and Latin America under different brand names, including:

• Cyclofem
• Feminena
• Lunella
• Lunelle (This was the first and only CIC approved for use by the U.S. Food and Drug Administration in 2000, but it was voluntarily recalled and discontinued three years later because there were concerns about its effectiveness. Since then, no CIC has been submitted for approval in the United States.)
• Mesigyna
• Novafem

CICs are given every 28 to 30 days into the buttock or shoulder.

These shots are said to be 99% effective. However, research has shown that because they only provide protection for 30 days and are, therefore, less convenient, people often miss a shot. This lowers effectiveness.

CICs also contain less progestin than Depo-Provera or Noristerat, so people are more likely to have monthly cycles with this type of birth control.