3 Types of Birth Control Shots

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Updated on October 16, 2020

A birth control shot is a form of hormonal contraception used to prevent pregnancy. As opposed to oral contraceptives, which require daily pill-taking, birth control shots provide pregnancy protection lasting from 30 days to 12 weeks with but a single injection.

There are several options marketed around the world, which vary by the hormones used and how long the protection lasts, but only one (Depo-Provera) is approved for use in the United States.

Depo-Provera

Teenager receiving contraceptive injection. — Peter Dazeley / Getty Images

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 progestin, which are synthetic versions of the female hormone progesterone.

Progestins work by keeping progesterone levels stable. By doing so, the different phases of the menstrual cycle cannot be triggered and ovulation cannot occur.

Depo-Provera is 99% in preventing pregnancy if taken as directed, although it's real-world efficacy is said to be around 94%. In addition to preventing pregnancy, Depo-Provera is approved for use in treating endometriosis and abnormal uterine bleeding.

Each Depo-Provera injection lasts for around 12 weeks. There are two versions currently available in the United States:

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

Medroxyprogesterone acetate is also sold under other brand names, including Curretab, Cycrin, Farlutal, Gestapuran, Perlutex, and Veramix.

The Depo Provera carries a black box warning advising consumers of the risk of significant and often irreversible bone mineral loss with long term use. Depo-Provera is also associated with an increased risk of breast cancer and should not be used in women with a 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 introduced shortly before Depo-Provera in 1957.

Although not approved for use in the United States, Noristerat is considered safe with similar efficacy and side effects as Depo-Provera. Used widely in the United Kingdom, Latin America, Africa, and parts of Europe, Noristerat is included on the World Health Organization's List of Essential Medicines.

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

As with Depo-Provera, Noristerat is delivered by injection into the muscle of the shoulder or buttocks.

Where Noristrat differs from Depo-Provera in its duration of protection, which lasts for only eight weeks. This means that you would have to come in for a shot every two rather than four months, making it far less convenient.

On the flip side, women who used Noristrat are able to return to fertility faster once treatment is stopped, often within three months.

Combined Injectable Contraceptives

Although not available in the United States, there are combined injectable contraceptives (CICs) that contain both progestin and a synthetic form of estrogen called estradiol. These are the same hormones used in combination birth control pills, the birth control patch, and the NuvaRing.

CICs are available mainly in Africa, Asia, and Latin America under various brand names, including:

Cyclofem
Feminena
Lunella
Lunelle
Lunella
Mesigyna
Novafem

Lunelle was the first and only CIC approved for use by the U.S. Food and Drug Administration in 2000 but was voluntarily discontinued three years later due to concerns about its effectiveness. There have since been no CIC submitted for approval in the United States.

CIC shots, given every 28 to 30 days into the buttock or shoulder, are said to be 99% effective. On the downside, because they only provide protection for 30 days, they are less convenient, and women will often miss a shot.

Because CICs also contain less progestin that Depo-Provera or Noristerat, women are more likely to have monthly cycles.

A Word From Verywell

Given that Depo-Provera is the only option available in the United States, speak with your doctor about the pros and cons of use compared to birth control pills or other forms of hormonal contraception.

Despite its convenience, Depo-Provera may cause side effects and pose health risks to certain women. This includes a greater risk of weight gain, mood changes, loss of libido, and osteoporosis compared to its oral counterparts.