What are the short-acting oral contraceptives?

Short-acting oral contraceptives mainly include the following types: 1. Norethisterone Tablets (Oral Contraceptive Pills No. 1): Each tablet contains 0.625 mg norethisterone and 0.035 mg ethinylestradiol. It prevents pregnancy by altering the endometrial environment and inhibiting ovulation. 2. Medroxyprogesterone Acetate Tablets (Oral Contraceptive Pills No. 2): Each tablet contains 1 mg medroxyprogesterone acetate and 0.035 mg ethinylestradiol, which also provides effective contraception. 3. Drospirenone-Ethinylestradiol Tablets: A combined preparation primarily composed of drospirenone and ethinylestradiol, it prevents pregnancy by inhibiting ovulation and altering cervical secretions. 4. Ethinylestradiol-Cyproterone Acetate Tablets: Composed of cyproterone acetate and ethinylestradiol, it inhibits ovulation and increases the viscosity of cervical mucus, thereby achieving contraceptive effects. It is important to note that short-acting oral contraceptives must be taken strictly according to medical instructions. Missing doses or arbitrarily changing dosage should be avoided to ensure contraceptive effectiveness.