Yosmin is chemically known as drospirenone ethinyl estradiol tablets; the difference between drospirenone ethinyl estradiol tablets 28 and 21 is the difference in the dosage of drospirenone and ethinyl estradiol per tablet and the different ways of using them. Drospirenone ethinyl estradiol 21 tablets contain 3 mg of drospirenone and 0.03 mg of ethinyl estradiol per tablet, while drospirenone ethinyl estradiol 28 tablets contain 24 tablets containing 0.02 mg of ethinyl estradiol and 3 mg of drospirenone, and 4 tablets do not contain a hormone control tablet. Drospirenone Ethinyl Estradiol 21 Tablets are usually used from the first day of menstruation for 21 days, and menstruation occurs after the drug is discontinued. Drospirenone Ethinyl Estradiol 28 Tablets generally need to be taken from the 1st day of menstruation without stopping the drug in between, and the final negative tablet is a placebo. It is contraindicated in patients with hepatic impairment, in women with severe liver disease; in patients with renal impairment, in women with severe renal insufficiency or acute renal failure. Therefore, if you need to apply the contraceptive pill, it is recommended that it is best to go to the hospital and use the drug under the guidance of a doctor to avoid causing serious adverse reactions.