Oral Contraceptive Preparation

**Semantic type:** Chemical Viewed Functionally

**Definition:** Orally administered synthetic sex hormones with contraceptive activity. The oral contraceptive preparation contains a combination of an estrogen, such as ethinyl estradiol, and a progestagen, such as levonorgestrel or norethidrone. The oral contraceptive prevents pregnancy by preventing ovulation and by inducing endometrial and cervical changes undesirable for fertilization and implantation.

**Synonyms:** - birth control pill - oral contraceptive pill