Progesterone is a progesterone secreted by the corpus luteum of the ovary and is indicated for diseases caused by progesterone deficiency. For thick endometrium, i.e. endometrial thickening, taking progesterone has certain therapeutic significance, but at the same time, it is easy to have side effects such as gastrointestinal reaction, allergic reaction, dizziness and vaginal bleeding: 1. Gastrointestinal reaction: progesterone is a hormone drug, after taking it, a small percentage of people will stimulate the digestive tract, causing gastrointestinal discomfort and symptoms such as nausea and vomiting; 2. Allergic reaction: a small percentage of patients will have Allergic reactions: a small percentage of patients will have allergic reactions after using the drug, such as skin itching and rash; 3. Dizziness: because of the similarity with adrenal hormones, some patients will experience dizziness after taking the drug; 4. Vaginal bleeding: after stopping the drug, patients may suffer from massive vaginal bleeding due to endothelial shedding, which may cause anemia and other symptoms. So for patients with thickened endothelium, if you take progesterone, you can take it before bedtime to reduce the impact caused by the occurrence of side effects. Pay attention to whether there is abnormal bleeding after stopping the medication, and if so, go to the hospital for treatment in time.