Yes. Contrary to the medications used for ovarian stimulation, endometrial preparation protocols are possible with just medications taken orally.
In the case of estrogens, they can be administered orally or via transdermal patches.
As for progesterone, it can be administered orally or with vaginal pessaries. Since the side effects of oral pills are more common, the second option is preferable.
However, in those cases where the patient’s ovaries work but oral contraceptives are not used, GnRH analogues may be necessary, which are administered intravenously (injections) to stop the endogenous hormonal activity.
Suggested for you: Endometrial Preparation for Implantation After IVF Embryo Transfer.