There are two main types of EC pills: Progestin only pills containing levonorgestrel, and combined pills, which contain both progestin, and an estrogen.

Both of these types of EC pills are simply a higher dose of regular birth control pills.

EC with progestin only has been found to produce fewer side effects and be somewhat more effective than EC made with a combination of progestin and estrogen. As of 2006, virtually all dedicated brands of EC - packaged specifically for EC use - contain only a progestin called levonorgestrel.

The table below shows the formulation of common EC pills. For more detailed information of products available by country, please consult the ICEC pills database.

EC Pill Formulations

Formulation (per pill) Number of pills Common Brand Names Levonorgestrel 1.5 mg 1 Escapelle, Norlevo 1.5 Levonorgestrel 0.75 mg 2 Levonelle-2, NorLevo, Plan B, Postinor-2, Vikela Levonorgestrel 0.03 mg 50 Microlut, Microval, Norgeston Levonorgestrel 0.0375 mg 40 Ovrette

Note: Many EC pills contain two pills, with instructions to take the second pill 12 hours after the first. However, research has found that levonorgestrel-only EC pills are as effective if taken in a single dose. ICEC therefore recommends taking EC as a single dose, even when using two-pill products. (See our Regimen Policy Statement). Taking the pills in one dose or in two doses 12 hours apart is equally safe and effective; taking both pills at once may be easier.

Many brands of regular combined oral contraceptives can be used to make EC. For information on what regular birth control pills are for EC use and are available in your country, please go to www.Not-2-Late.com.