When is birth control effective?

When you start a new method of birth control it is important to know when it will become effective. This is different for each type of birth control.

The combined pill

(sometimes just called the pill)

If you start taking the combined pill in the first 5 days of your cycle (ie on the first day of your period or in the following 4 days) it will be immediately effective and you will be protected from getting pregnant straight away.

If you start taking the combined pill at any other time in your cycle you need to use another method of contraception for 7 days as it is not effective immediately, however once you have been taking it for 7 days you will be protected from getting pregnant.

The progesterone only pill

(sometimes called the mini pill)

If you start taking the mini pill in the first 5 days of your cycle (ie on the first day of your period or in the following 4 days) it will be immediately effective and you will be protected from getting pregnant straight away.

If you start taking the pill at any other time in your cycle you need to use another method of contraception for 2 days as it is not effective immediately, however once you have been taking it for 2 days you will be protected from getting pregnant.

The implant

If you have an implant fitted in the first 5 days of your cycle (ie on the first day of your period or in the following 4 days) it will be immediately effective and you will be protected from getting pregnant straight away.

If you have an implant fitted at any other time in your cycle you need to use another method of contraception for 7 days as it is not effective immediately, however once you have had your implant for 7 days you will be protected from getting pregnant.

Contraceptive injection

If you have a contraceptive injection in the first 5 days of your cycle (ie on the first day of your period or in the following 4 days) it will be immediately effective and you will be protected from getting pregnant straight away.

If you have a contraceptive injection at any other time in your cycle you need to use another method of contraception for 7 days as it is not effective immediately, however from 7 days after your injection you will be protected from getting pregnant.

IUD

(sometimes called the copper coil)

An IUD can be fitted at any time in your menstrual cycle and is effective immediately. You will be protected from getting pregnancy as soon as it is fitted.

IUS

(sometimes called the hormonal coil)

If you have an IUS fitted in the first 7 days of your cycle (ie on the first day of your period or in the following 6 days) it will be immediately effective and you will be protected from getting pregnant straight away.

If you have an IUS fitted at any other time in your cycle you need to use another method of contraception for 7 days as it is not effective immediately, however from 7 days after it is fitted you will be protected from getting pregnant.

Contraceptive patch

If you start using patches in the first 5 days of your cycle (ie on the first day of your period or in the following 4 days) it will be immediately effective and you will be protected from getting pregnant straight away.

If you start using patches at any other time in your cycle you need to use another method of contraception for 7 days as it is not effective immediately, however once you have been using patches for 7 days you will be protected from getting pregnant.

Vaginal ring

If you start using the ring on the first day of your cycle (ie the first day of your period) it will be immediately effective and you will be protected from getting pregnant straight away.

If you start using the ring at any other time in your cycle you need to use another method of contraception for 7 days as it is not effective immediately, however once you have been the ring for 7 days you will be protected from getting pregnant.

Helen Burkitt, Senior Sexual Health Nurse at SH:24
Written by Helen Burkitt. Senior Sexual Health and Contraception Nurse

Last updated at: 10 March 2022