You will need supplemental estrogen and progesterone medications to prepare your uterine lining for the FET. You will also continue these medications after the FET. Estrogen is often given in the form of injections on every third day. You may also need progesterone injections or vaginal suppositories every day as instructed after the lining sonogram check. If you are unable to tolerate injectable medications, you can discuss with your physician alternative forms of these medications.