How long does it take birth control to work? A complete guide
Whether you favor mini pills or a copper IUD, every contraceptive varies in its method of action, how it’s administered—and how quickly it can start preventing pregnancy.
But because many popular forms of birth control depend on timing, it’s essential to know when your contraceptive method of choice will start to kick in.
Knowing when and how your birth control will start guarding you against pregnancy, will better ensure your family planning stays on track and on your terms. So how long does it take birth control to become effective? Let's take a look.
Methods and types of birth control
No matter your lifestyle, sexual preferences, or ability to stick to a schedule (no shame in being a free spirit!), there is typically some form of birth control that may fit your needs best. Each birth control method and type also works differently.
Let’s take a look at how popular types of contraceptives work and, most importantly, when.
What are the different kinds of birth control?
There are a host of ways to take control of family planning and prevent pregnancy, from flexible solutions to permanent ones.
One category of birth control recognized by sexual health experts is long-acting reversible contraceptives (LARC). These are designed to put pregnancy out of mind for longer durations (from 3 to 10 years) and may be removed at any time if your family plans change.
There are three main kinds of LARCs:
Hormonal IUDs – Intrauterine devices are small, T-shaped wands inserted into your uterus that can work to prevent pregnancy for typically 3-5 years. While inside you, they mete out small portions of the hormone progestin, which keep sperm from encountering your egg after ovulation. Hormonal IUDs can also stop ovulation altogether, as well as make it more difficult for sperm to reach your egg if you do ovulate. Fewer than 1% of people get pregnant using a hormonal IUD.
Copper IUDs – Copper IUDs look similar to hormonal IUDs. Instead of using hormones to keep sperm away, they use copper (a natural sperm-repeller). This type of IUD typically works to prevent pregnancy for 10 years once inserted and is more than 99% effective at preventing pregnancy. The Copper IUD is also the most effective form of emergency contraception. If you have an oops moment, getting a Copper IUD inserted can help you avoid pregnancy now and for as long as you leave it in place.
Hormonal implants – Hormonal implants work by releasing small pulses of progesterone into the bloodstream. They’re placed under your skin in your upper arm and are typically effective at preventing pregnancy for 3 years. Hormonal implants are more than 99% effective at protecting against pregnancy.
In addition to these three, you may consider opting for short-acting contraceptive methods. These birth control strategies operate on shorter timelines, which means you’ll have to remember to use them regularly for them to be effective.
Short-acting birth control methods include:
Birth control pill – The birth control pill, also referred to as combination birth control or simply “the pill,” is one of the most popular types of oral contraceptives. A combination pill containing two hormones, progestin and estrogen, like Cryselle birth control, is taken each day for 3 weeks, followed by a week of inactive (or inert) pills. The two hormones together work to stop ovulation, thereby protecting against unwanted pregnancy. With perfect use, combination birth control pills are 99% effective. The combination birth control pill can also be used to skip or delay your period, as needed.
The mini pill – The mini pill, or progestin-only pill, is an oral contraceptive that contains a single hormone: progestin. Progestin halts ovulation and makes it more difficult for sperm to merge with an egg after ovulation. The mini pill must be taken every day at the same time to be effective at preventing pregnancy. If taken with perfect use, mini pills are more than 99% effective. The mini pill is safer for people who have a history of blood clots, migraines with aura, or recently had a baby, along with other health conditions.
Birth control patch – A birth control patch, or contraceptive patch, is a topical adhesive placed on the skin’s surface to prevent unwanted pregnancy. It works by releasing small doses of estrogen and progestin into the bloodstream each day, thereby inhibiting both ovulation and fertilization. Each patch can protect against pregnancy for 1 week. Patches are over 99% effective at preventing pregnancy.
Birth control vaginal ring – A vaginal ring, such as NuvaRing or Annovera birth control, is a contraceptive that’s inserted into the vagina. It resembles a small disc and (much like tampons) cannot be felt while inside you. NuvaRing works by releasing estrogen and progestin into the bloodstream to prevent ovulation and fertilization. It won’t interfere with your sex life, but it must be changed monthly to remain effective at preventing pregnancy. NuvaRing is over 99% effective at preventing pregnancy.
Birth control shot – The birth control shot is a kind of injected contraceptive. It administers the hormone progestin, which prevents ovulation from occurring and makes it more difficult for sperm to fertilize an egg. The birth control shot must be taken every 3 months to prevent unwanted pregnancy. With perfect use, shots are more than 99% effective.
Both long-acting and short-acting methods of birth control are hormonal methods of birth control: they deliver hormones to your body to prevent pregnancy from occurring.
If you prefer not to use a hormonal contraceptive, barrier methods of birth control are another effective option. Unlike hormonal contraceptives, barrier methods of birth control keep sperm from fertilizing eggs with structural and/or chemical solutions.
A bonus: some of them also offer a measure of protection against STDs.
There are four kinds of barrier contraceptives:
Condoms – Condoms are a kind of sheath, most often made of latex, that physically prevents semen from entering the vagina. Male condoms may be rolled over the penis to trap sperm inside, while female condoms may be worn inside the vagina to block sperm from entry. Condoms can also be used as backup birth control to the pill or in the instance of a missed pill. It is up to personal preference whether your method of pregnancy prevention should be condoms vs. birth control, like the pill.
Diaphragms – Diaphragms, which look like a small raised dome, prevent pregnancy by using a hybrid of barrier and chemical contraception. They are inserted into the vagina to block the cervix and are combined with spermicide (a solution that kills sperm) to keep fertilization from occuring. Diaphragms must be inserted within 6 hours before sexual intercourse and removed 6-8 hours afterwards to be effective.
Cervical caps – Cervical caps resemble and function like diaphragms, but they have a smaller fit. They are paired with spermicide and inserted into the vagina to deter sperm from entering and fertilizing an egg. Diaphragms should be inserted before having sex and removed no fewer than 6 hours after intercourse.
Sponges – Birth control sponges use a chemical solution (spermicide) to kill sperm and prevent pregnancy from occurring. Before having sex, they are inserted into the vagina to obstruct the cervix and removed 6 hours after sexual activity.
Aside from hormonal and barrier methods of birth control, many individuals elect to use the fertility awareness method (FAM). This is a family planning technique that uses awareness (rather than hormones or physical apparatuses) to gauge when ovulation occurs and abstain from sex during that period. FAM can be effective, but it depends on your capacity to track your reproductive rhythms—and the assumption of their regularity.
Lastly, if you’re certain you do not want to have children, both people assigned male and female at birth may pursue surgical sterilization to permanently prevent pregnancy.
How long does each type of birth control take to work?
Whether you’re in the heat of the moment or are making long-term choices about your reproductive health, it’s vital to know which contraceptives are your go-tos for staying protected.
But how long does it take birth control to work?
To save you some Googling sprees, we’ve whipped up a cheat sheet on when each typically becomes effective:
IUDs – If inserted up to 5 days after intercourse, IUDs are still 99% effective at preventing pregnancy.
Hormonal implants – If correctly implanted within the first 5 days of your menstrual cycle, you’re likely to be protected from pregnancy immediately.
Birth control pill – Combination birth control is likely to prevent pregnancy immediately if taken between days 1 and 5 of your period.
Birth control mini pill – If you take it between days 1 and 5 of your period, the mini pill is likely to work immediately.
Birth control patch – The birth control patch will likely protect against pregnancy immediately if applied between days 1 and 5 of your period.
Birth control vaginal ring – If inserted between days 1 and 5 of your period, vaginal rings start protecting against pregnancy immediately.
Birth control shot – The shot will be effective for preventing pregnancy if you get it within 1 week of the beginning of your menstrual cycle.
While statistically less effective than hormonal birth control, barrier methods (condoms, diaphragms, sponges, and cervical caps) work to prevent pregnancy immediately. Remember, however, that while they can protect against STDs, they’re less effective at preventing pregnancy.
Factors that can affect birth control efficacy
There’s one caveat to keep in mind with contraceptive efficacy rates: their ability to prevent pregnancy is in its prime with perfect use.
In other words, you must use them correctly—and with no extraneous interfering factors—for them to work. There are several circumstances that may render your birth control of choice less effective:
You missed a pill – For combination pills or progestin-only oral contraceptives to work, you need to maintain the levels of estrogen and/or progestin that each of your pills contains during a missed pill. When you miss one, your hormone levels dip, making it more likely you’ll get pregnant if you have sex. While mini pills revolve around a stricter schedule, it’s generally not too difficult to recover if you miss 1 or 2 doses of combination birth control pills. If you skipped a day and are concerned about getting pregnant, use a barrier method during intercourse and adhere to your medication’s instructions to get back on your regular schedule.
You’re taking medication – Certain medications, including ones that affect digestion, may influence the efficacy of oral contraceptives. Because oral contraceptives pass through your digestive system to work, enzyme-inducing drugs and some herbs can interfere with the rate at which the pill is metabolized. For this reason, always consult with your healthcare provider to ensure any medicine you need to take won’t make you vulnerable to pregnancy.
You missed your switch-out date – Certain types of birth control, like vaginal rings, patches, and shots, have an expiration date. While they take longer to stop preventing pregnancy, IUDs also lose their effectiveness after a period of a few years. For this reason, it’s crucial to establish a reminder system to prompt you to switch them out on a regular schedule.
You had sex during your fertile window – Some 14 to 25% of women and people who menstruate are estimated to experience menstrual irregularity, which means predicting ovulation can vary from month to month, or throughout their lives. If you depend on FAM or barrier contraceptives and have sex during your fertile window (the time period following ovulation), you may be slightly more likely to get pregnant.
General side effects and symptoms of birth control
It’s not uncommon for hormonal methods of birth control to yield some side effects—especially if you’re just getting used to them.
There are several common side effects many people experience while on birth control:
Breakthrough bleeding or “spotting”
Fortunately, many of these side effects may dissipate once your body gets used to its new normal. If you experience unusual and irregular bleeding, vaginal discharge, or severe pain, be sure to check with your health care provider to be safe.
The takeaway: why knowing your birth control by heart matters
So: how long does it take birth control to work? The answer depends on which method you’re using—and no matter your timing, there’s bound to be a solution out there for everyone.
Ultimately, birth control isn’t just about keeping babies out of your future (at least for the time being!). It’s about taking control of your physical, mental, and emotional well-being—claiming autonomy over your present, and your future.
By knowing what to expect from each type of birth control—and, most importantly, when it starts having your back—you’ll begin a new chapter of your reproductive healthcare journey with confidence.
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