How does the contraceptive injection given every three months work
The contraceptive injection given every three months contains a hormone similar to one your own body makes, and works mainly by stopping the release of an egg. It is very effective when given on time, suits women who want private protection without a daily pill, and often makes periods irregular, lighter or absent.
What is the contraceptive injection, and how does it work?
The contraceptive injection is a small injection given into a muscle, usually in the upper arm or the buttock, once every three months. It contains a hormone similar to one your own body makes, released slowly over three months. It protects you in three ways. Mainly, it stops your ovaries from releasing an egg each month, so there is no egg to be fertilised. It also thickens the mucus at the neck of the womb, making it hard for sperm to pass through, and it keeps the lining of the womb thin. When each injection is given on time, it is a very effective method of contraception. If the first injection is given at the start of a period, it usually protects you straight away; at other times you may need to use condoms for a short while, and we will tell you exactly what to do.
Who is the injection a good choice for?
The injection suits many women, and some especially well. It may be right for you if you find a daily pill hard to remember, or you have ever spent anxious days after a missed pill. It suits women who want their contraception to be completely private, because there is nothing to keep at home, nothing to carry and nothing for anyone else to find. It can suit women who have been advised to avoid the combined pill, and it is often suitable while breastfeeding, with your doctor advising when to start. Some women also find that their periods become lighter and less painful on it. Before the first injection, the doctor asks about your health and any medicines you take, checks your blood pressure, and makes sure you are not pregnant, so that it is a safe choice for you.
Who might prefer a different method?
The injection is not right for everyone, and it is better to know that at the start. If you hope to become pregnant soon after stopping, another method may suit you more, because after the last injection it can take some months for your fertility to return, and sometimes longer. It does return, but not straight away. When a pregnancy is in your plans, our guide on how to become pregnant may help. It is also worth knowing that, once given, the injection cannot be taken out, so any side effects last until it wears off. Some health conditions make other methods more suitable, which is why we go through your history carefully first. If the injection is not right for you, we will help you choose something that is.
What happens to your periods?
Changes to your periods are the most common effect, and knowing about them in advance takes away a lot of worry. In the first months, you may have spotting, or bleeding at unexpected times, sometimes for longer than usual. Over time, periods often become lighter and less frequent, and for many women they stop altogether while they continue the injections. This is expected and is not harmful. The blood is not building up inside you; the lining of the womb is simply staying thin. Your periods return after you stop. Some women also notice a little weight gain, headaches or changes in mood. If any change troubles you, please tell us. You do not have to put up with it; we can talk through what can be done, or whether another method would suit you better.
Is it safe to use for a long time?
For most women, yes, with regular review. If the injection is used for many years, it can cause a small reduction in bone strength, which usually recovers after stopping. For this reason we review the method with you from time to time, and talk about whether it is still the right choice as your life and plans change. Staying active and eating a balanced diet support healthy bones in any case. It is also important to know what the injection does not do: it does not protect against sexually transmitted infections. Condoms do, so you may want to use them as well, especially with a new partner. Each injection is given in person at the hospital in Goa, with a fresh single-use syringe and needle opened just for you.
What if I am late for my next injection?
Coming back on time is the most important part of using the injection well. Each time, we tell you the date of your next injection. Save it in your phone with a reminder a few days ahead. If you realise you are late, please do not simply carry on as if nothing has happened, and do not guess. Call or message us. Depending on how late you are, we may need to check that you are not pregnant before giving the next injection, and we will tell you whether to use condoms until you are protected again. If you have had intercourse while late and you are worried, contact us promptly so we can advise you. A short call is always better than days of worry, and you will not be judged for being late.
Will my visit stay private?
Yes. Contraception is a private matter, and we treat it that way. Married or unmarried, you are welcome, and you are treated with the same respect and discretion. Nothing about your visit is shared with your family or anyone else, and there is no packet at home to explain. We do not send injections or any medicines by post; each injection is given in person, so that we can check you are well and keep your timing on track. If you want to compare the injection with other options, such as the pill, an implant or an intrauterine device, we can go through them together, and our guide to preventing an unplanned pregnancy may also help. This guide is by Dr Mayur Pai, MBBS, MS in Obstetrics & Gynaecology.
Getting started
If you would like to find out whether the contraceptive injection given every three months is right for you, call or message us. We will talk it through with you privately, answer your questions, and arrange a visit to the hospital in Goa for your first injection. Free patient transport is available from across Goa and nearby areas, and you can also reach us through our contact page. This article is for education only and is not personal medical advice; please consult your doctor about your own situation.
How often do I need the contraceptive injection?
Every three months. We give you the date of your next injection each time. If you are late, call us before carrying on, as you may need a pregnancy check and condoms until you are protected again.
Is it normal for my periods to stop on the injection?
Yes. Periods often become irregular at first and may then become lighter or stop altogether. This is expected and not harmful, and your periods return after you stop the injection.
How soon can I get pregnant after stopping the injection?
It can take some months for fertility to return after the last injection, and sometimes longer. It does return. If you plan a pregnancy soon, tell us, and we can suggest a different method.
Or call +91 75582 52088 · 0832 251 3641
This page is for general education and is not personal medical advice. Treatment depends on your own examination and reports, so please speak to a doctor about your situation. We do not carry out or offer sex determination of any kind.