The clinical adverse reactions of progesterone are as follows: 1. dizziness may occur after taking progesterone pills, most typically about 1-3 hours after taking progesterone pills, so it is recommended to take them before bedtime. 2. headache, nausea or depressed mood may occur. 3. withdrawal bleeding or spotting-like vaginal bleeding may occur after stopping the drug. Bleeding. There may be localized changes in the discharge from the cervix, and there may be a decrease in libido. These are the clinical reactions to progestin use. Very rarely, fungal infections may occur, but they do occur. It is recommended that the appropriate medication be given under the guidance of a doctor, and that the medication must not be missed during the period of administration, as irregular vaginal bleeding may occur if the medication is missed.