How Long Does It Take for Birth Control to Work?

There are lots of different factors that come into play when choosing the birth control method that works best for you. How much does it cost? How easy is it to access? What are the side effects? And one of the most important: How long does it take for birth control to work?

The answer varies depending on the type of birth control you’re considering. Some methods, such as condoms, work immediately. However, birth control methods that work by preventing ovulation, such as the pill, can take some pre-planning, since their efficacy takes a little while to kick in.

Here are the must-know stats on the different methods of birth control, how long it takes for the birth control to work and which fits in best with your lifestyle and preferences (like how often you want to take a pill or re-insert a ring, for example).

Illustrations of the different types of hormonal birth control, including pills and shots.

Hormonal Birth Control

How long hormonal birth control takes to work varies based on the type of hormonal contraceptive you use and the time of the month you start taking it. With any hormonal birth control, if you’re not sure if you’ve waited long enough for it to be effective, you should either use a back-up form of contraceptive or abstain from having sex until you believe you’ve waited long enough for it to be effective.

Injection or “Shot”

The most commonly known brand of this type of birth control is the Depo Provera shot. It uses progestin to stop your body from releasing an egg from your ovaries and is administered by a doctor.

How long does it take to work?
This depends on when in your cycle you get your first shot. If it’s within five days of the first day of your period, you will be fully protected within 24 hours. If, however, your shot is outside that timeframe, you’ll need to use a backup method for seven days before the hormones take effect to prevent pregnancy.

Things to remember:

  • You need to get a follow-up shot every 12 weeks to maintain efficacy.
  • If you wait more than 14 weeks to get your follow-up shot, you’ll need to use a backup method for seven days.

Combined Oral Contraceptives

Combined oral contraceptives, such as Aviane, Levora, Ortho Tri-Cyclen, and Yaz contain estrogen and progestin, which suppress ovulation.

How long does this birth control take to work?
This type of pill begins to work immediately if you take it on the first day of your period. However, if you don’t take the first pill at the start of your period, you’ll need to wait seven days before having unprotected sex to prevent pregnancy.

Things to remember:

  • Though the combo pill is one of the most widely used forms of birth control, approximately 10% of women will become pregnant while using it.
  • You must take a pill every day, preferably at the same time of day, to maximize its effectiveness.

Progestin-only Pill

The progestin-only pill, or “mini-pill,” works by making it more difficult for sperm to move and for an egg to attach to your uterine lining. These pills are sold under the names Camila, Errin, Jolivette and Micronor, among others.

How long does this birth control take to work?
If you choose to take the mini-pill, you should avoid having unprotected sex for two days after starting the pills.

Things to remember:

  • The progestin-only pill needs to be taken at the same time each day.
  • If you miss a dose, use a backup method for two days after you begin taking the pill again.

Hormonal Vaginal Contraceptive Ring

The NuvaRing is a popular brand of vaginal contraceptive ring, and it contains the same hormones as combo pills. It’s a flexible ring that must be prescribed by a doctor, but you will insert it each month yourself.

How long does this birth control take to work?
If you insert the vaginal ring on the day you start your period, you’re immediately protected from pregnancy. If you begin using it at any other time of the month, you’ll need to use a back-up method for seven days.

Things to remember:

  • The ring is worn for three weeks each month and removed for one week.
  • You must insert the ring on time each month to ensure you’re protected against pregnancy.
  • With typical use, the ring is 91% effective.


The best-known brand of birth control patch is Ortho Evra. The patch is just what it sounds like: a sticky patch that is placed on your skin, which contains estrogen and progestin to prevent fertilization.

How long does this birth control take to work?
 Once you apply the first patch, there is a seven-day wait before you are fully protected against pregnancy. If you choose to have sex during that window, use a secondary form of birth control.

Things to remember:

  • You need to put on a new patch every week for three weeks, then take a week off, during which you’ll get your period.
  • The patch must be applied to clean, dry skin on your upper arms, stomach, butt or shoulder.

Illustrations of different types of barrier method birth control, including condoms and the sponge.

Barrier Methods

Barrier methods of birth control are physical barriers to sperm, which need to be used every time you have sex in order to prevent pregnancy. These methods typically begin to work immediately.

Diaphragms and Cervical Caps

A diaphragm is a small saucer-shaped piece of silicone that is inserted inside your vagina prior to intercourse. A cervical cap is similar to a diaphragm, but is shaped differently and fits more tightly against your cervix. Both methods work by covering your cervix to prevent sperm from entering your uterus.

How long does this birth control take to work?
Diaphragms and cervical caps start working right away. To be most effective, these forms of birth control need to be used properly and fit well. Work with your doctor to understand how to insert them and ensure they’ll properly protect you.

Things to remember:

  • These forms of birth control need to be used in conjunction with spermicide.
  • If you have a baby, you will need to be refitted for your diaphragm or cervical cap.


The only brand of contraceptive sponge currently sold in the United States is the Today Sponge. It contains spermicide and is placed in the vagina, where it fits over the cervix.

How long does this birth control take to work?
The sponge starts working right away and is effective for up to 24 hours.

Things to remember:

  • The sponge must be left in the vagina for at least 6 hours after the last act of intercourse.
  • Like diaphragms and cervical caps, sponges need to be used properly and fit well to be most effective.

External Condom

External (or “male”) condoms, such as Trojan and Durex, are typically made of latex. To be most successful, they must be used correctly. This means putting the condom on before any skin-to-skin contact or penetration. After ejaculation, while holding the condom at the base of the penis, remove the condom from the penis and dispose of it in the garbage.

How long does this birth control take to work?
The external condom is effective at preventing pregnancy with immediate use.

Things to remember:

  • You must use a new condom each time you have sex to prevent pregnancy.
  • This is the only type of birth control that is also effective in preventing STDs/STIs.

Internal Condom

Internal (or “female”) condoms such as Femidom and Dominique are latex pouches with a ring at each end that are inserted into the vagina prior to intercourse. Like external condoms, they must be used correctly to be most effective. You will insert the top ring inside your vagina and keep the lower ring on the exterior. Right after intercourse and before standing up, squeeze the exterior ring and twist it to contain the semen inside, then dispose of the condom in the trash.

How long does this birth control take to work?
The internal condom works to prevent pregnancy immediately upon insertion.

Things to remember:

  • Internal condoms are 75-82% effective with normal use.
    They are not thought to be as effective at protecting against STDs/STIs as male condoms.


Vaginal spermicides come in many forms: foam, cream, gel, suppository and film. The spermicide is inserted inside the vagina and uses chemicals to prevent the sperm from reaching the egg.

How long does this birth control take to work?
Different types of spermicide take different amounts of time to become effective, so you should always check the directions on the package.

Things to remember:

  • You’ll need to add more spermicide each time you have sex.
  • Spermicide is not very effective when used on its own, so it’s best paired with another form of birth control, such as a condom or diaphragm.
  • Using a spermicide multiple times per day can irritate your vaginal lining, which can increase your risk of contracting an STD or STI.

Illustration of the IUD and birth control implant

IUDs and Implants

IUDs and implants are the longest-lasting forms of birth control, aside from sterilization. The amount of time these methods of birth control take to work varies depending on the type you decide to use.


The contraceptive implant is sold in the United States under the name Nexplanon. It is a small plastic rod inserted under the skin of the upper arm by a doctor.

How long does this birth control take to work?
If inserted within five days of your period starting, it begins protecting against pregnancy immediately. If it’s inserted at any other time of the month, you won’t be fully protected against pregnancy until after the first seven days, and you will need to use a back-up barrier method.

Things to remember:

  • The implant is effective for up to three years.
  • Implants are one of the most effective methods of preventing pregnancy.

Intrauterine Devices (IUDs)

An intrauterine device (IUD) is a small device inserted into the vagina by a doctor. There are two types: hormonal (Mirena, Liletta, Skyla) or non-hormonal (ParaGard). Most gynecologists will wait to insert a hormonal IUD until the week of your expected period.

How long does this birth control take to work?
If a hormonal IUD is inserted within seven days of the beginning of your period, you’re immediately protected against pregnancy. If your IUD is inserted at any other time of the month, you should use a back-up barrier method for the next seven days.

ParaGard, specifically, can be inserted at any time during your menstrual cycle and is effective immediately.

Things to remember:

  • IUDs are effective anywhere from 3-10 years, depending on the type used.
  • They can be removed by your doctor at any time to resume fertility.
  • ParaGard can also be used as emergency contraception. If inserted within five days of unprotected sex, it is almost 100% effective.

So, how long does it take for birth control to work? The answer is that it varies. Although that can be frustrating, the time it takes to be effective is definitely something to be aware of when you’re researching the best options for you.

It’s also important to keep in mind that most forms of birth control are only effective for preventing pregnancy and do not protect against STDs/STIs. If you suspect that you’ve been exposed to an infection, you should get STD tested as soon as possible.