How long does the pill take to work?

Medically reviewed by

Last reviewed: 04 Nov 2021

Depending on when you take the pill, it can get to work straight away so you’re protected from pregnancy. There are many different types of contraceptive pills to choose from when trying to prevent pregnancy, and you may be wondering how long the pill takes to work.

Let’s have a look at the difference between the combined pill and mini pill, and how long each takes to work.

Contents

Somebody about to take the contraceptive pill

How long does it take for the pill to work?

How long it takes for the pill to work depends on the type of pill you take. It could take between 1 to 7 days for the pill to take effect, depending on when you begin taking it, as long as you take it daily when you should, and do not miss any.

Combined pill

The combined pill is made of the hormones oestrogen and progesterone. This protects you from pregnancy by preventing the sperm from reaching the egg or by stopping ovulation (the release of the egg) that cycle.

You can start taking the combined pill at any point in your menstrual cycle. When you start taking the pill will determine when it begins to work.

If you start taking the combined pill between the first and fifth day of your period, you will be protected straight away.

But, if you start taking your combined pill after the fifth day of your period, you need to take it for 7 days in a row before you are protected. Use a condom during these 7 days so you do not get pregnant.

Mini pill

The mini pill is a progestogen only pill that prevents pregnancy by making sure that the sperm does not reach the egg.

When starting the mini pill, you should decide what time you want to take your pill, and continue taking it at the same time every day.

Similar to the combined pill, when the mini pill begins working is dependent on when you start taking it.

If you start taking the mini pill during the first 5 days of your period (days 1 to 5 of your menstrual cycle), it will start working right away. You will not need to use additional contraception, like condoms.

You will need to use a condom for the first 2 days of taking the pill if you begin taking the pill on any other day of your cycle, or if your normal period usually lasts less than 5 days.

How effective is the pill?

The contraceptive pill is 99% effective at preventing pregnancy if you take your pill without missing any. This means the pill is just as effective (99%) as the copper intrauterine device (IUD) and the contraceptive implant.

The pill is more effective than female diaphragms, which are only 88% effective, and female condoms that are only 95% effective.

However, the pill is not effective at preventing sexually transmitted infections (STIs), so it’s best to use a male condom when you have sex.

Am I still protected if I miss a pill?

If you miss a pill or start a new pack of pills late, you may be less protected from pregnancy.

The chance of getting pregnant when you miss a pill is dependent on:

how many pills you missed
where on the blister strip you missed the pill (either the beginning or end)
which contraceptive pill you are taking

You should read the patient information leaflet that comes with your pack of pills, or speak to a doctor for advice if you miss a pill.

	Is your risk of pregnancy increased?	What to do now?
You forgot 2 or more pills after your pill-free interval (9 or more days have passed since the last active pill)	Yes	take the most recent missed pill as soon as you remember continue with your regular schedule use extra protection (like condoms) for the next 7 days talk to your GP about emergency contraception if you’ve had unprotected sex during or after the pill-free interval
You forgot 1 pill in week 1 of your current month (the 1st pill was taken correctly)	No	take the missed pill as soon as you remember continue with your regular schedule you do not need to use extra contraception
You forgot 2-7 pills in week 1 of your current month (the 1st pill was taken correctly)	Yes	take the most recent missed pill as soon as you remember continue with your regular schedule use extra protection (like condoms) for the next 7 days talk to your GP about emergency contraception if you have had unprotected sex during the pill-free interval or week 1
You forgot 1 pill in week 2 or week 3 of your current month (or in any subsequent week if you skip the pill-free interval)	No	take the missed pill as soon as you remember continue with your regular schedule you do not need to use extra contraception
You forgot 2-7 pills in week 2 or week 3 of your current month (or in any subsequent week if you skip the pill-free interval)	Yes	take the most recent missed pill as soon as you remember continue with your regular schedule if you have forgotten to take 2 or more pills before your pill-free interval, pass over the pill-free interval use extra protection (like condoms) for the next 7 days emergency contraception is not necessary
You forgot more than 7 consecutive pills (in any week of the current month)	Yes	if you want to continue taking the pill, you take it as if you’re newly starting it use extra protection (like condoms) for the next 7 days talk to your GP about emergency contraception

Source: https://www.nhs.uk/conditions/contraception/miss-progestogen-only-pill/

Mini pill

If you forget to take the mini pill (progestogen only pill), you may not be protected depending on how long it has been since you forgot to take it. There are 2 types of mini pills, and they either need to be taken within the same 3 hour period or 12 hour period, each day.

	Is your risk of pregnancy increased?	What to do now?
You forgot 1 pill and remember within the window for taking it (3 or 12 hours depending on the exact brand)	No	take the missed pill as soon as you remember continue with your regular schedule you do not need to use extra contraception
You forgot 1 pill and notice after the window for taking it (3 or 12 hours depending on the exact brand)	Yes	take the missed pill as soon as you remember continue with your regular schedule use extra protection (like condoms) for the next 2 days talk to your GP about emergency contraception if you’ve had unprotected sex within 48 hours after missing your pill

Source: https://www.nhs.uk/conditions/contraception/miss-progestogen-only-pill/

Medically reviewed by:
Dr Kathryn Basford

Dr Kathryn Basford is a qualified GP who works as a GP in London, as well as with ZAVA. She graduated from the University of Manchester and completed her GP training through Whipps Cross Hospital in London.

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Article created: 04 Nov 2021

Last reviewed: 04 Nov 2021

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Sources

NHS combined contraceptive pill [July 2020] [accessed October 2021]
NHS miss combined pill [February 2019] [accessed October 2021]
NHS the progestogen-only pill [February 2021] [accessed October 2021]

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