What is the standard single dose of levonorgestrel used for emergency contraception?

• A. 1.5 mg
• B. 0.5 mg
• C. 2.0 mg
• D. 3.0 mg

Answer: (A)

Levónorgestrel emergency contraception works mainly by delaying ovulation, so delivering a high dose shortly after unprotected intercourse prevents ovulation and the resulting chance of fertilization. The standard single-dose regimen is 1.5 mg taken at once. This dose has been shown to be as effective as regimens that split the dose and is easier to use, which improves adherence and timely use. For best results, take it as soon as possible after unprotected sex—ideally within 24 hours and up to 72 hours afterward—the sooner it's taken, the higher the chance of preventing pregnancy. It is not an abortion medication and will not terminate an established pregnancy; its effectiveness wanes as time passes. Common side effects include nausea or mild abdominal discomfort, and if vomiting occurs shortly after taking the dose, a repeat dose may be needed. The other listed doses are not the standard single-dose recommendations.