Emergency Contraception

Emergency contraception (EC) is a special dose of synthetic hormones taken within 72 hours (may be helpful up to 120 hours) after sexual intercourse to prevent pregnancy. EC is also called the “morning-after pill.”

There are two types of EC. One type contains only progestin; the other type contains estrogen and progestin. These are the same synthetic hormones that are in many birth control pills, but not all birth control pills can be used as emergency contraception. Be sure to consult a clinician before using birth control pills as emergency contraception.

If taken within 24 hours after unprotected sexual intercourse, progestin-only EC reduces the risk of pregnancy by up to 95%. Effectiveness drops to 89% if taken between 24 and 72 hours afterwards. EC that contains both estrogen and progestin reduces the risk of pregnancy by about 75%. EC reduces the chance of pregnancy if taken up to 120 hours later, but its effectiveness decreases as time passes.

Getting EC

Community Pharmacy
341 State St. | 608-251-4454

Walgreens (many locations)
Locations with a 24-hour pharmacy
606 South Whitney Way | 608-274-1311 | Located across from the west transfer point.
3710 E Washington Ave | 608-242-9483

Reasons to consider EC

If intercourse occurred within the past 120 hours and no birth control was used or the birth control failed, EC can reduce the risk of pregnancy. Reasons to consider using EC include:

sexual assault
no birth control used
condom breaking or slipping
missed 2 or more daily birth control pills or started a new pill cycle late
late inserting a new ring, replacing a patch, or getting a contraceptive injection
dislodged diaphragm or cervical cap
natural family planning miscalculation
withdrawal or failed withdrawal

EC is often chosen by women who have been sexually assaulted as a way to reduce the risk of pregnancy. We strongly encourage victims of assault to talk with a clinician about preventive treatment of sexually transmitted infections and options available for counseling and other support.

How EC works

When used as emergency contraception, synthetic hormones disrupt the natural hormone patterns necessary for pregnancy. They work similarly to other hormonal methods of contraception by primarily preventing or delaying ovulation and also by preventing fertilization of an egg or by preventing implantation of a fertilized egg.

Emergency contraceptive pills will not work if already pregnant, nor do they harm an already established pregnancy or cause an abortion.

How to use EC

EC should be used as soon as possible within 120 hours after unprotected sexual intercourse. To prevent nausea, eat a snack such as a sandwich and milk, yogurt, or a regular meal before taking the pills.

Because EC is much more effective if used within the first 24 hours, consider purchasing EC to have on hand before it is actually needed.

Progestin-only pills (Plan B):
Progestin-only pills (Plan B) may be swallowed as one dose of two pills. Plan B is generally well-tolerated and produces no side effects except for mild nausea in some women. Plan B is currently available without a prescription at many, but not all, pharmacies.

Combination oral contraceptives:
Multiple doses of birth control pills containing estrogen and levonorgestrel (synthetic progestin) can be prescribed as EC. These pills are swallowed as two doses taken exactly 12 hours apart and, while effective, may have more side effects, such as:

nausea, ranging from mild to severe, with possible vomiting
breast tenderness
irregular bleeding
fluid retention
headaches

These symptoms generally taper off and resolve within 24 to 48 hours after the second dose of medication.

Warning signs associated with estrogen-containing EC

Although estrogen-containing EC is safe for most women, they hormone medications can increase the risk of blood clots. See a clinician immediately if any of the following symptoms develop:

pain in the calf or thigh
chest pain or shortness of breath
severe headaches, dizziness, weakness, or numbness
blurred vision, loss of vision, or trouble speaking
severe abdominal pain

EC and the menstrual cycle

The next period may be earlier or later than usual and the flow may be heavier, lighter, or spottier.

EC substantially reduces the risk of pregnancy but it is not 100% effective. If a period does not start within three weeks after taking the pills, a pregnancy test is recommended. Urine pregnancy testing is available at UHS during regular clinic hours, without an appointment.

After taking EC

EC does not reduce the risk of pregnancy for any future episodes of intercourse. It can be safely taken in the future should another episode of unprotected intercourse occur.

Although prescriptions are no longer necessary to obtain EC, an appointment is generally recommended to discuss birth control options and to screen for sexually transmitted infections. EC does not protect against sexually transmitted infections. To protect against HIV, other sexually transmitted diseases, and pregnancy, use condoms with every sexual encounter.

Use condoms, spermicide, or other methods of contraception consistently to protect against pregnancy. If interested in starting a prescription method of birth control, discuss the options with a clinician. It may be possible to start a hormonal method, such as birth control pills, skin patch, or vaginal ring, immediately after taking EC.

Other resources:
For more information on emergency contraception that includes a listing of birth control pills that can be used as EC, visit ec.princeton.edu or call the Emergency Contraception Hotline toll-free at 1-888-NOT-2-LATE.