The Plan B pill is emergency contraception that can be used up to 72 hours after a birth control failure or unprotected sex. Plan B is Levonorgestrel taken in two doses 12 hours apart. Women over 18 can purchase Plan B from their pharmacist without a prescription, making it a safe and accessible option when you are concerned about the possibility of pregnancy. Learn the risks of Plan B, the benefits, and how and when to use Plan B.

What is Plan B

Plan B is a contraceptive, not an abortive drug. The hormone in Plan B is a synthetic form of progestin. While the post-coital use of this hormone is fairly new, the drug has been used in birth control pills for decades. Plan B works by preventing ovulation, fertilization and implantation. Like traditional birth control pills, it will not harm an established pregnancy after implantation.

How to use Plan B

If you have had unprotected sex, were raped, had a condom break or missed more than two birth control pills, Plan B may be right for you. Take one pill as soon as possible and the next pill 12 hours later. Plan B will not work if you are already pregnant. The second dose may be taken a bit earlier if necessary without reducing efficacy; however, this can worsen the side effects.

How effective is Plan B

If taken within 72 hours, Plan B reduces your risk of pregnancy by approximately 89 percent. Taken within 24 hours of sex, it can reduce the risk of pregnancy by as much as 95 percent. It does not reduce or prevent the risk of sexually transmitted diseases. Plan B is substantially less effective than using traditional contraceptives, like birth control pills or condoms.

What are the risks of Plan B

Plan B uses a synthetic hormone traditionally used in birth control pills. The dosage is high, but serious side effects are uncommon. Typical and expected side effects include vomiting, nausea, fatigue, diarrhea and menstrual irregularities. If your period is more than seven days late, you may be pregnant even after taking Plan B. Women who cannot take typical birth control pills due to health concerns can typically take Plan B safely, even more than once. Consult a pharmacist or physician if you are taking medications that may conflict with Plan B, including antibiotics.

How often can you take Plan B

You can take Plan B more than once in a cycle if needed, or multiple times a year without worry. There are no health risks to taking this commonly used hormone more than once. The effectiveness may be reduced with multiple uses; however, it is still better to use Plan B than not in case of a contraceptive failure. Plan B is not a cost-effective contraceptive, and is not as effective as many hormonal or barrier methods used consistently or during sex. If you do take Plan B more than once in a cycle, you are more likely to have menstrual irregularities as well as other side effects.

Below is some more info on emergency contraception and the Plan B pill: