Contraception: three-month injection (depot injection)

The three-month injection contains the hormone progestin as a contraceptive. Principle: It is injected into the gluteal muscle or a muscle on the upper arm every three months

Three-month injection: Rather for the exceptional case (also shown in the picture: contraceptive ring, pill)

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There is also that sometimes: A woman can hardly tolerate any of the common contraceptive methods or cannot cope with them, but does not wish to have a child in the near future. Then the three-month or depot injection is an option.

When is the three-month injection an option?

Doctors usually only prescribe the contraceptive in exceptional cases. The three-month injection contains a high dose of progestin. It is injected into the muscle. The active ingredient is slowly released from the depot.

The method is primarily suitable for women who cannot tolerate other contraceptives or who cannot use contraceptive pills, for example because of a chronic gastrointestinal disease. The products currently available contain either the progestin medroxyprogesterone or the progestogen norethisterone acetate.

Carefully weigh the benefits and risks of a method of contraception: Find out exactly what you're doing

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Important: consultation with a doctor and examination

The doctor will carefully weigh the reasons and wishes in favor of a depot injection. In a conversation with the woman and on the basis of a thorough gynecological examination, he checks whether the health requirements are met or whether there are any possible contraindications. For example, the woman must have a normal cycle. A general medical examination is also recommended before the first use of the contraceptive tip.

Pregnancy excludes the use of the syringe, as the high dose of hormones can harm the unborn child.

In principle, the hormone depot is injected into a muscle in the upper arm or buttocks every twelve weeks. The first time this happens during the first five days of the monthly cycle. If the injection takes place at a different time, the doctor must first make sure that the person concerned is not pregnant.

Two to three months after the first injection, the doctor will check with the woman whether the method can be continued.

The half-yearly appointments with the doctor (gynecologist, general practitioner) suggested in the following period should also be observed by the woman so that she can recognize side effects early and react to them. In particular, because of the possible risk of osteoporosis, he will check the bone density regularly (see below).

Only if other contraceptive methods continue to be ruled out and there are no contraindications or restrictions will the doctor generally consider using the hormone injection for more than two years.

How does the three-month injection work?

The progestin contained in it inhibits ovulation and suppresses the build-up of the uterine lining so that an egg cell that may have been fertilized cannot implant itself. The hormone also makes the mucus in the cervix thicker. As a result, the sperm capitulate: They can practically no longer penetrate the uterus.

Advantages of the three-month injection

The three-month injection is considered a contraceptive with good contraceptive reliability. The users "only" have to have an injection every three months. The method is suitable for women who want long-term contraception or whose family planning has already been completed. But: It is only an alternative in the event that other methods, including contraceptive pills, are not an option.

On the positive side, it should be noted that menstrual pain can subside and that there are no errors in taking, as can be the case with the pill.

If the right time for the next injection is missed, there is still a few days left, namely the 13th week.

Disadvantages of the three-month injection

If the last injection was more than 13 weeks ago, the contraceptive protection is no longer safe. It is best that the woman then consults her doctor.

If the administration of the depot syringe is stopped, it can take over a year before the normal cycle is restored. Therefore, the method is not suitable for women who are planning a pregnancy in the foreseeable future.

Some medications, for example certain antibiotics, can affect the way the progestin works. Other interactions are also known. You should also inform the attending physician and your pharmacy about this.

Side effects of the three-month injection

The three-month injection interferes with the hormonal balance of women and can cause various side effects in this direction. High doses of progestin appear in the body, especially at the beginning. Often the period becomes irregular as a result. Spotting and intermenstrual bleeding are possible, and the menstrual period may not occur at all.In addition, there are often feelings of tension and pain in the breasts, sexual desire can decrease (changes in libido), mood swings and even depression can occur.
Note: For the technical and user information on hormonal contraceptives (hormonal contraceptives, here: the three-month injection), warning notices are provided (or have already been included) that draw attention to an increased risk of suicide as a possible consequence of depression. Women who experience mood swings and symptoms of depression while using a contraceptive should seek medical advice promptly from their doctor, even if the agent was recently used for the first time.

Possible side effects also include headaches, abdominal pain, back pain, acne, retention of fluids, weight gain, liver disorders, jaundice, pigment spots on the skin (more on this in the article "The Pill").

The hormone injection also reduces bone density and increases the risk of osteoporosis. This is due to the fact that the body's own estrogen drops significantly under the syringe. But it is needed for bone building. Since the body creates the bulk of the bones at a young age, gynecologists are particularly reluctant to use hormone injections in young women.

However, the doctor will advise an appropriately contraceptive woman on how best to meet her calcium and vitamin D needs. Both are especially important for the bones.

Finally, the body may experience allergic reactions to ingredients in the syringe, as well as inflammation or bleeding at the injection site.

The user and her gynecologist will decide when the therapy should be stopped and therefore not further hormone injections, be it for medical or other reasons.

Contraindications to the three-month injection

The most important contraindications to the three-month injection include unexplained bleeding from the vagina, existing phlebitis or vein thrombosis. A thrombosis is a vascular occlusion caused by a blood clot, for example in a leg vein.

Diseases such as breast cancer or uterine cancer, severe liver diseases, metabolic diseases such as porphyria, which can affect the blood or liver, and osteoporosis also exclude the use. The same applies to a known allergy to components of the drug.

When is particular caution necessary?

For smokers who use hormones for contraception, the risk of arterial vascular diseases such as heart attacks and strokes increases significantly from the age of 35 and with the number of cigarettes consumed daily.

High blood pressure and metabolic disorders, such as sugar and fat metabolism, are also among the situations in which caution is required when using hormonal contraception.

The doctor will work with the woman to find out whether an alternative method of contraception is an option if all of these risks cannot be adequately controlled.


The three-month injection can protect against unwanted pregnancies, but not against sexually transmitted diseases such as HIV / AIDS.

Pearl index: 0.3 to 0.88