The contraceptive injection
The contraceptive injection is a hormonal method you get every few months instead of taking something daily or weekly. In South Africa it is one of the most widely used methods, partly because it is simple once you are on it and no one needs to know you are using it. This page explains how the injection works, how effective it is, what the trade-offs are, and who it tends to suit.
How the injection works
The injection contains a progestogen (a hormone similar to the natural progesterone your body makes). A common example in South Africa is Depo-Provera. Depending on the type, it is given every 2 to 3 months, usually into the muscle of the upper arm or buttock.
Like other hormonal methods, it prevents pregnancy mainly by stopping your ovaries from releasing an egg. It also thickens the mucus at the neck of the womb, which makes it harder for sperm to get through. Because the hormone is stored in your body and released slowly, one injection keeps working for the full 2 to 3 months.
How quickly does it start working?
Timing matters. If the injection is given in the first 5 days of your period, it can protect you against pregnancy within about 24 hours. If it is given at any other point in your cycle, you will usually need to use condoms or another backup method for about 7 days while it takes effect. A doctor or nurse will tell you which applies to you based on when you have it.
How effective is it?
The injection is a very effective method. With correct and on-time use it prevents pregnancy in more than 99 out of 100 women. The main thing that reduces its effectiveness in real life is being late for the next dose, so keeping to the schedule is the one habit that really counts.
One thing worth being clear about: the injection does not protect against sexually transmitted infections. Only condoms do that. If STIs are a concern for you, using condoms alongside the injection covers both bases.
The pros
- Nothing daily or weekly to remember. Once you have had the injection, you are covered for 2 to 3 months with no pill to take and no patch to change.
- Private. There is no packaging at home and nothing to keep in a bag or on a shelf, which suits women who want their contraception kept completely to themselves.
- It does not interrupt sex. Protection is there in the background.
- Oestrogen-free. Because it contains only a progestogen, it can be an option for some women who cannot use methods that contain oestrogen (for example certain migraines, high blood pressure, or smoking over the age of 35). Whether it is right for you is a decision to make with a doctor.
- Often lighter or no periods. Many women find their bleeding gets lighter over time, and some stop having periods altogether, which some see as a benefit.
The cons
- Bleeding changes. Irregular bleeding or spotting is common in the first few months, especially at the start. For some women it settles into no bleeding at all, but the unpredictable phase can be frustrating.
- Return to fertility can take longer. After you stop the injection, it can take several months, sometimes up to a year, for your periods and fertility to return to normal. If you are hoping to fall pregnant in the near future, this is worth thinking about and discussing with your doctor.
- You cannot take it back once given. Unlike a pill you can simply stop, the injection stays in your system for its full duration, so any side effects last until it wears off.
- You have to keep to the schedule. Being late for your next dose can leave you unprotected, so it suits people who can reliably get back for the next appointment.
Some women also notice changes in weight, mood or headaches. These vary a lot from person to person, which is exactly why a proper assessment before starting is useful.
Who might it suit?
The injection tends to work well for women who want reliable contraception without a daily or weekly routine, who value privacy, and who are not planning a pregnancy in the next year or so. It is also worth discussing if you cannot use oestrogen-containing methods and want a progestogen-only option that is not a daily pill.
It may suit you less if you want your fertility to return quickly after stopping, or if unpredictable bleeding in the early months would bother you. There is no single best method, only the one that fits your health, your life and your plans. If you are weighing up your choices, our guide to choosing contraception compares the options side by side, and you can also read more about the pill and the patch.
Where do you get the injection?
The injection has to be given by a trained person, so it is usually done at a clinic or pharmacy rather than at home. Public clinics in South Africa offer it free of charge. Private clinics and many pharmacies offer it too, often with shorter waits and more privacy.
Our online consultation covers the pill and the patch, which you can start and receive without leaving home. The injection needs an in-person visit for the actual jab, so if the injection is what you want, a clinic or pharmacy is the place to go. If you are still deciding between methods, an online consultation is a good way to talk it through with a doctor first.
A quick note on safety
Certain conditions affect which methods are safe for you, which is why a doctor assessment matters before starting any hormonal contraception. In South Africa, minors can access contraception confidentially, and every method carries its own balance of benefits and side effects.
This page is general information, not personal medical advice. Whether the injection is right for you should be decided with an HPCSA-registered doctor who knows your health history.