The contraceptive injection or the synthetic progestogen is a means of contraception, injected intramuscularly every three months. It is effective for 12 weeks.

How does the progestin injection work?

The progestin injection is made up of the progestin hormone (medroxyprogesterone acetate). It works in three ways:

  • It blocks ovulation,
  • Thickens the cervical mucus to limit the passage of sperm,
  • Atrophies the uterine lining to prevent nidation
    Intramuscular progestin injections should be given at regular intervals by a doctor, nurse or midwife.

How effective is the progestin injection?

The theoretical effectiveness of the progestin injection is 99.7% (1 in 100 people who use this method of contraception become pregnant each year). However, it is important to add that its practical effectiveness is estimated at 94%, which can be explained mainly by delays in injection due to the hazards of daily life.

What if I am late for my injection?

It is possible to give your progestogen injection 10 weeks after your last injection and at the latest, 15 weeks after. If the 13-week deadline has passed, you should check that you are not pregnant before giving the injection. If you have not received an injection within the above-mentioned period, you will no longer be protected and may be at risk of an unwanted pregnancy. It is then advisable to use another method of contraception, such as a condom, while waiting for the next injection.

Is the progestin injection suitable for all women?

The progestin-only injection can be used by all women. However, it greatly reduces normal oestrogen levels, and consequently decreases bone mineral density.
Therefore, it is not recommended for teenagers, young women, and women with or at risk of osteoporosis (diffuse skeletal disease).

How do I get a progestin-only injection?

The progestin injection is prescribed by a doctor. It is available in pharmacies with a prescription and the price for a quarterly dose is approximately €5.32. The cost is covered up to 65% by Social Security.
The injection can be given by a doctor or a nurse, and requires an appointment. The professional (doctor, gynaecologist, nurse or midwife) injects the medicine into the arm or buttocks. This procedure is painless.

LUNA helps you :

The LUNA AGENDA feature allows you to use your menstrual cycle data to

Predict your period and know the day of ovulation to predict or avoid pregnancy.

Allows you to evaluate your fertility potential according to your age for information purposes, and to follow your fertility period according to your menstrual cycle. You can also record your temperature readings within LUNA.

It is important to respect the dates of the injections in order to have an almost optimal efficiency. For this reason, we advise you to enter your progestin injection in your LUNA diary so that you do not forget it.

What are the advantages of the progestin injection?

The advantages of the progestogen injection are :

  • Its effectiveness
  • Practicality: you only have to remember to take your injection 4 times a year, unlike the pill which has to be taken daily.
  • The injection is discreet, it is not visible.
  • The injection can reduce or even stop the flow of periods. For women with painful or heavy periods or chronic illnesses (e.g. endometriosis), the injection can therefore be beneficial.

What are the disadvantages of the progestin injection?

Although the progestin injection has significant advantages, it also has some disadvantages:
– The injection must take place every 3 months, your appointment must be made in advance. In order for the contraceptive effect to last, your appointments for your next injection must be made in advance, and you must go on the date indicated. If you have a very active life, with many unforeseen events, or live far from a health centre, another method of contraception may be more practical (implant, IUD, etc.).

  • If you want to become pregnant, stopping the progestin injection may delay your ability to become pregnant for up to 10 months.
  • You may experience side effects from the progestin-only shot, as you might from another method of contraception.

What are the side effects of the progestin-only injection?

Every woman is different and may react differently to taking contraception. The progestin injection may cause some side effects that may disappear a few months after the first injections:

  •  More frequent bleeding than usual (small bleeding between periods
  • Absence of periods
  • Nausea
  •  Weight gain
  • Headaches
  • Sore breasts

If you experience any side effects after several months, it is strongly advised that you speak to your doctor or gynaecologist to assess the suitability of your contraceptive method, and/or whether a change in treatment strategy is necessary.

I took my progestin-only injection today. Am I protected?

If the contraceptive injection takes place within the first 5 days of your period, protection is activated immediately. In the case of an injection at another time of your menstrual cycle, or following a change of contraception, it is necessary to use a condom, and to follow your doctor’s recommendations as to the duration during which this mechanical barrier is necessary, while waiting for the contraceptive effect linked to the injection to be active.