Method	Dosage	Time interval*	Reported efficacy (%)
Combination oral contraceptives	Two doses of 100 mcg of ethinyl estradiol plus 0.5 mg of levonorgestrel (Plan B), taken 12 hours apart	72 hours	75 to 80
Levonorgestrel	Two doses of 0.75 mg, taken 12 hours apart,	72 hours	75 to 80
	or
	One dose of 1.5 mg
Copper intrauterine device (ParaGard)	—	120 hours	99