How many days after birth control pill is it effective

For many women, taking the contraceptive pill is an easy and effective way to prevent getting pregnant. It's physically non-invasive, and all you have to do is remember to take the tablet at more or less the same time every day. Then, it's 99% guaranteed you won't get pregnant.

Wondering what happens if you miss a pill? We've got a complete guide for you. And another thought: how long does it actually take before the hormonal effects of the pill kick in when you start taking it?

The pill promises to prevent the release of your egg and therefore your chance of fertilisation. But is there a time frame, after you start taking the pill, where the egg release continues to happen?

We've spoken to two doctors to get the verdict on when your contraceptive pill actually begins to protect you against pregnancy.

Find out exactly how long you'll need to wait until you find yourself in the condom-free safe-zone (where pregnancy is concerned, this is, obviously only have unprotected sex if you're certain your partner is STI free).

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Keep reading.

How long does it take for the pill to work?

According to doctor Dianni Dai, GP at Pulse Light Clinic, it depends when you start taking your contraceptive pill in relation to your cycle. "If you start taking the combination pill on the first day of your period, you’ll be protected against pregnancy right away," she explains.

However, if you start your pill pack after your period has started, you’ll need to wait seven days before having unprotected sex. "If you have sex during this time, be sure to use a condom for at least the first week as you are not protected," she continues.

Houda Ounnas, GP at 25 Harley Street, agrees, further adding that how long it takes for a contraceptive pill to work depends on the type of the pill you are taking, too.

The combined pill

If you are taking the combined oral contraceptive pill—the one most commonly prescribed—then listen up. "The combined pill takes longer to work and only starts to be effective after seven days of continuous use, starting on day one of your next period," she explains.

According to the NHS website, this seven day allowance for it to work only applies if you start taking the pill on day six or later of your menstrual cycle. Your menstrual cycle begins on the first day of your period.

If you start the combined pill between days one to five of your period, the NHS advises that "you will still be protected from pregnancy straight away, unless you have a short menstrual cycle (your period is every 23 days or less)". So, if you have a short menstrual cycle, or you start taking it any later in your cycle than day five, condoms it is.

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The mini pill

If you are taking the mini pill, the rules vary slightly, she explains. "You only need 48 hours of continuous use of the mini pill, not seven days, regardless of where you are in the cycle." You also don’t need to wait for your next period to start.

That means that after only two days of taking this pill, it’s already in your system and registered a reliable form of contraception.

So what's the catch? "It’s important to note that if you miss this pill, or are late in taking it, you don’t have 24 hours to catch up," she explains. "Depending on the particular brand, the window of time during which you need to take it varies from three to twelve hours."

Her advice? Always check the individual brands’ recommendation. "If you miss one of these pills, you will need 48 hours of continuous use for it to become effective again, the same as when you first started it. There is no variation according to the cycle." Got that?

Why aren't you always protected from the day you take the pill?

Because, in short, it can take up to seven days for the pill to become effective and for your body to register the protection.

"During this time, you should use another form of birth control", explains doctor Dianni.

How effective is the pill?

When taken correctly, the pill is over 99% effective at preventing pregnancy, both doctors confirm. "This means that fewer than 1 in 100 who use the combined pill as contraception will get pregnant each year," explains Dr Dianni.

Having said that, it is true that some forms of birth control work better than others.

The kinds of birth control that work the best to prevent pregnancy are:

• the implant
• IUDs, like the coil

They’re also the most convenient to use, and the most foolproof, Dianni shares.

Other birth control methods, like the pill, ring, patch, and shot, are also really good at preventing pregnancy but only if you use them perfectly.

"But people aren’t perfect, and these methods are easier to mess up than implants and IUDs," explains doctor Dianni. You were warned.

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So, pills don't provide instant protection?

Many people assume that the contraceptive pill provides instant protection against pregnancy. "That is certainly not the case with most hormonal-based pills," explains doctor Dianni. The only exception, she explains, is the copper IUD. "This acts as spermicide and therefore provides protection straight away upon insertion."

Another important thing to note here: birth control pills do prevent you against getting pregnant (seven days after taking), but do not protect against STIs. "It is wrong to assume ‘safe sex’ can be achieved with birth control alone. Condoms are important tools for preventing STI transmission," adds Dianni.

Am I protected against pregnancy if I miss one pill?

In short, yes. If you have missed one pill anywhere in the pack or started a new pack one day late, you are still protected against pregnancy. But, there are certain steps you should take to ensure you're in safe hands.

Make sure to:

• Take the last pill you missed now, even if this means taking two pills in one day
• Carry on taking the rest of the pack as normal
• Take your seven day pill-free break as normal, or if you're on an everyday pill, take your dummy (inactive) pills
• You do not need to use extra contraception.

If you have missed two or more pills anywhere in the pack, or if you've started a new pack two or more days late (48 hours or more), your protection against pregnancy may be affected, the doctor shares.

Her advice? "Condoms are your safer sex superhero: they’re the only way to get protection from both pregnancy and STDs during vaginal sex. "

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