Let's take a minute to talk about your medication. This is progesterone. It helps to treat irregular menstrual periods. It also can help to protect the lining of the uterus. Progesterone may have other uses, too. Progesterone is a capsule that is taken by mouth. Make sure to take each dose with a full glass of water. You should take it exactly as your doctor tells you to. You should swallow the capsules whole. If you have trouble swallowing, ask your pharmacist for advice. Most people tolerate this medicine well. Common side effects include headaches, breast pain, and vaginal bleeding or spotting. You may also have an upset stomach, nausea, and feel tired or dizzy. These effects are normal if they are mild and should go away. You should wait until you know how it affects you before you do activities that require you to be alert, like driving. If these or other side effects become reasons you want to stop taking this medicine, please talk to your doctor or pharmacist. As with any medicines, rare but serious side effects can occur. With progesterone, this can include risk of heart attacks, stroke, blood clots, or dementia. It can also increase the risk of breast cancer. You should read the Patient Information Sheet to know which symptoms to watch for and when to report changes to your doctor. Progesterone can interact with other medicines. You should always check with your doctor or pharmacist before taking other medicines. Also, tell your doctor if you are allergic to peanuts before taking this medicine. Women should check with their doctors before becoming pregnant and before breastfeeding. For best results with progesterone, take it exactly as directed, and plan ahead for refills.