The “Yuzpe method” is a regimen for emergency contraception developed in 1977. It consists of 2 doses of 100 ug ethinyl estradiol and 0.5 mg levonorgestrel taken 12 hours apart. Although there are a variety of pills formulated in this manner, it is possible to achieve this dose with 8 low-dose OCPs taken at the same time.
It must be done less than 72 hours after unprotected intercourse. It results in a 75% reduction in pregnancy, and common side effects include nausea and vomiting (sometimes patients are given a prescription for meclizine along with the pills).
Caveat: if a woman doesn’t bleed within 4 weeks of taking emergency contraception, she should be tested for pregnancy.
The Yuzpe method is NOT the same as Plan B, which is levonorgestrel alone (and has a higher efficacy rate). Plan B and the copper IUD are the two most effective forms of emergency contraception.