DrugDigest: Levonorgestrel Emergency Contraception ( Plan B ): Information on dosage, usage, side effects, interactions, and drug comparisons, including generics when available.
MedlinePlus: Progestins For Contraceptive Use (Systemic): Provides information on usage, precautions, side effects and brand names when available. Data provided by government agencies and health-related organizations.
Plan B: About a progestin-only emergency contraceptive available in the U.S. ("If Plan A fails, go to Plan B...")
Plan B - Emergency Contraception: Official Canadian website with information for patients and health professionals.