Levonorgestrel

pharmaceutical drug

Levonorgestrel is a hormonal medication which is used in many birth control methods.[1] It is combined with an estrogen to make combination birth control pills.[2] As an emergency birth control, sold under the brand names Plan B One-Step and Julie, among others, it is useful within 72 hours of unprotected sex.[3] The more time that has passed since sex, the less effective the medication becomes, and it does not work after pregnancy (implantation) has happened.

Levonorgestrel works by preventing ovulation or fertilization from happening.[4] It decreases the chances of pregnancy by 57–93%.[5]

References

change
  1. "Progestins (Etonogestrel, Levonorgestrel, Norethindrone)". The American Society of Health-System Pharmacists. Archived from the original on 2015-09-07. Retrieved Aug 21, 2015.
  2. Postgraduate Gynecology. Jaypee Brothers Medical Pub. 2011. p. 159. ISBN 9789350250822. Archived from the original on 2015-09-26.
  3. "Levonorgestrel 1.5 mg Tablet Emergency Contraceptive: New Drug Application 21998, Supplement 5" (PDF). U.S. Food and Drug Administration.
  4. "Now Is the Time to Change Label on Emergency Contraceptives". Relias Media | Online Continuing Medical Education | Relias Media - Continuing Medical Education Publishing. Retrieved 2022-08-16.
  5. Gemzell-Danielsson K (November 2010). "Mechanism of action of emergency contraception". Contraception. 82 (5): 404–409. doi:10.1016/j.contraception.2010.05.004. PMID 20933113.