Active Ingredient

Levonorgestrel

Levonorgestrel is a type of hormone used in various contraceptive methods. It is commonly used to prevent pregnancy after unprotected intercourse or contraceptive failure.

This ingredient is also found in some long-term birth control options.

Written By Douglas C. Goldberg, MD

Reviewed By Philip Schein, MD

Last Updated 28 Nov 2025

Available Levonorgestrel Brands

Plan B

Strengths 1.5 mg

I-Pill

Strengths 1.5mg

Levonorgestrel Uses

Levonorgestrel is primarily used for contraception. It can be used in different forms depending on the situation.

Emergency contraception after unprotected sex
Long-term birth control in certain devices
Management of heavy menstrual bleeding in some cases
Prevention of pregnancy in planned contraceptive regimens

How Levonorgestrel Works

Levonorgestrel works by preventing ovulation, which means it stops the release of an egg from the ovary. This reduces the chance of fertilization.

It also thickens the cervical mucus, making it more difficult for sperm to reach any egg that may have been released.

In some forms, it alters the lining of the uterus, preventing a fertilized egg from implanting.

Common side effects of Levonorgestrel

Not everyone experiences side effects from Levonorgestrel, and many side effects are mild and temporary.

Nausea
Headache
Dizziness
Breast tenderness
Irregular bleeding or spotting
Fatigue
Abdominal pain

If you experience serious or persistent symptoms, contact your doctor.

Monitor your symptoms and report any severe side effects to your healthcare provider.
Avoid using Levonorgestrel with heavy alcohol consumption as it may affect its efficacy.
Do not use Levonorgestrel if you experience unexplained vaginal bleeding.
Inform your doctor about any other medications you are taking to avoid possible interactions.
Discuss with your healthcare provider if you have any health conditions that may affect the use of Levonorgestrel.

Always consult your doctor for personalized medical advice.

Frequently Asked Questions

How quickly does Levonorgestrel work?

Levonorgestrel can work quickly, especially when used as emergency contraception. It’s most effective when taken as soon as possible after unprotected intercourse.

How long does the effect of Levonorgestrel last?

The immediate effect of Levonorgestrel for emergency contraception is temporary, but its presence in long-term contraceptive devices can provide ongoing prevention of pregnancy.

Is Levonorgestrel safe for everyone?

Levonorgestrel is generally safe for most women, but it’s important to discuss your medical history with a doctor to ensure it’s appropriate for you.

Can Levonorgestrel interact with other medications?

Yes, Levonorgestrel can interact with certain medications, which may affect its effectiveness. Always inform your healthcare provider about all the medications you are taking.

What should I do if I miss a dose of Levonorgestrel?

If you miss a dose, consult your doctor or pharmacist for guidance. They can provide advice based on your specific situation.