Birth control pills are highly effective at preventing pregnancy; when used properly, it is up to 99% effective. However, like all medications, the pill can take some time before it starts working as intended.
While the pill is meant to prevent pregnancy in sexually active women, there are other benefits that come with taking hormonal birth control. For example, the pill can make your period more regular, lighter and less painful. It can also help manage hormonal acne.
Depending on what you are taking the contraceptive pill for, you’ll need to wait a certain amount of time before the hormones in the pill you’re taking start to work.
How does the pill work?
Regardless of what you’re using the pill for, it’s helpful to understand how the pill works to understand why it may take some time before you start seeing its effects.
There are two types of oral contraceptive pills: the combined pill and the mini pill. The combined pill has a combination of estrogen and progestogen hormones in it while the mini pill only has progestogen hormones. Depending on your medical history and your needs, your doctor might prescribe you one pill over another.
The combined pill prevents pregnancy in a few different ways; it stops your ovaries from releasing eggs so there is no egg for sperm to fertilise, thickens your cervical mucus to make it harder for sperm to travel into your uterus and thins the uterine lining to make it more difficult for fertilised eggs to implant into the uterine wall.
The mini pill prevents pregnancy by thickening your cervical mucus to keep sperm from entering the uterus and thins the uterine lining to prevent implantation. For some women, the mini pill also prevents the ovaries from releasing eggs.
How does birth control affect your period?
Both the combined pill and mini pill have been shown to have positive benefits on menstrual cycles. Your period on the pill isn’t exactly the same as a normal period; it’s called withdrawal bleeding because your body is withdrawing from the hormones you’re taking every other day of the month.
Both the combined pill and the mini pill thin your uterine lining, so there’s less buildup for your body to shed during your monthly cycle. That means your “period” on the pill is usually lighter or shorter than when you’re not on the pill. The daily doses of hormones and 28 day pill packs also help regulate when you get your period each month. The pill can also help reduce pain and cramps by decreasing the amount of prostaglandin chemicals that your body produces that cause your uterus to contract. With fewer contractions, there is less pain and cramping.
These positive side effects of the pill make it a popular option for teens and women who aren’t necessarily sexually active or looking to use the pill as their only form of birth control.
The contraceptive pill for acne
The contraceptive pill is also helpful for managing hormonal acne. Hormonal acne is caused by an increase in androgens, or male sex hormones like testosterone, in your body. All women have small amounts of androgens in their bodies; they contribute to things like your strength, energy levels and fitness, as well as sebum production. This increase in androgens often happens around a woman’s period, leading to an overproduction of sebum which, in turn, causes breakouts and pimples.
When you take the contraceptive pill for acne, you’re taking female sex hormones daily, which helps lower the circulation of androgens in your body. However, it’s important to note that only the combined pill which has both estrogen and progestogen in it will help with acne, and only certain combinations will have an effect. The mini pill with just progestogen doesn’t improve acne. If you want to use the pill for acne, talk to your doctor.
So how long does it take for the pill to work?
There are a variety of factors that can affect how long it takes for the pill to work, from the time of your period to the type of birth control pill you use.
How long does it take for the combined pill to work?
To help prevent pregnancy, it depends on when you start taking the combined pill for it to be effective.
If you start taking combined birth control within five days from the start of your period, it will begin working immediately to prevent pregnancy. However, it’s still a good idea to use condoms or another backup form of birth control for at least a week after you start using the pill just to be safe and avoid getting pregnant.
If you start taking combined birth control more than five days after the start of your period or at another time during your menstrual cycle, you should use a backup form of contraception for a week to avoid becoming pregnant.
After seven days, the combined pill can be up to 99% effective when used properly and taken at the exact same time every day. However, “normal” use (the way most women use it in real life) reduces the effectiveness down to about 92%.
If you’re taking the pill to help manage your hormonal acne, it will take at least two to three months before you start to notice results.
If you’re taking the combined pill to help manage your period, you could start to see results during the first period you get on the pill. However, it’s important to note that you may experience spotting or breakthrough bleeding as your body gets used to the hormone, and it may take two to three months for your period to fully regulate.
How long does it take for the mini pill to work?
To help prevent pregnancy, the progestogen-only mini pill takes about 3 days to start providing protection. It’s recommended to use a secondary form of birth control during these first 3 days to be safe. It doesn’t matter when you start the mini pill in relation to your period.
Because the mini pill is progestogen only, it does not have any effect on managing hormonal acne.
The mini pill is not typically prescribed to help manage your period. You may experience irregular bleeding for the first few months. Irregular bleeding may include more or less frequent periods, lighter bleeding or spotting in between cycles. Some women might stop getting their periods altogether. Unlike the combined pill, the mini pill does not regulate your period. This means that you might experience no periods or unpredictable cycles while you’re on the mini pill.
Like any medication, it will take a little bit of time before it starts to work. For preventing pregnancy, always use a secondary form of birth control like condoms at the beginning to be safe. On the combined pill, it’s recommended to use backup contraception for 7 days. On the mini pill, it’s recommended to use backup contraception for 3 days. It may take 2 to 3 months on the combined pill to start seeing results with acne. You can start seeing effects on your period during the first month with the combined pill, and any side effects and irregularities typically subside after 3 to 4 months. Always talk to your doctor if you have any questions or concerns about your treatment and side effects, and follow your doctor’s instructions on how to take the pill for your needs.
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- Australian Family Physician (October 2017) - The management of irregular bleeding in women using contraception
- National Museum of Australia (April 2020) - The Pill
- Cleveland Clinic (July 2020) - Birth Control: The Pill