Can family planning injections fail to work?

Monday February 10 2020


By Dr Vincent Karuhanga

I recently had the three-month family planning injection administered. However, I have now tested and I am pregnant. Was the injection fake? Monica

Dear Monica,
Whereas it is true that some drugs on the Ugandan market may be fake, many times not taking drugs as prescribed, may be to blame.

The most common family planning injection used nowadays is Depo-Provera (Injectaplan) which if it is used according to instructions is more than 99 per cent effective. It is, therefore, likely that you never took the injection according to instructions rather than the drug being fake.

Women are advised to take the injection during their normal periods so that they do not take it when they are already pregnant. A urinary pregnancy test may be negative yet a woman is pregnant but the test has not yet started showing it.

The injection starts to work immediately after the first shot if it is taken within the first five days from the first day of your period.

If one gets the first Depo-Provera shot later than five days after the period starts, she may not prevent ovulation and therefore pregnancy, so she should use condoms for the first seven days following the injection to prevent pregnancy.


One must return for other shots every three months and here she is protected immediately after the injection.