Progestelle is a topical progesterone agent that can have many effects on the body. In order to review your particular case, it is important that you schedule an appointment with your gynecologist or your primary care physician in order for him or her to obtain a complete history, perform a physical examination (including a breast exam) and run any testing that is indicated.
Having said that, the growth of one of your breasts is likely due to the progestelle cream. Side effects of progesterone agents include breast tenderness and/or enlargement, and this is a common finding following its use. Other side effects of these types of medications include stomach upset, appetite changes, weight gain, swelling and edema, headache
, mood changes, and irregular menses and vaginal bleeding, to name a few of the most common effects. Although the area of use on your skin may play a role in which breast undergoes enlargement, this is variable, and using the progestelle on your other breast cannot guarantee that that breast will enlarge as well and provide symmetry. If this symptom is bothersome to you, I would recommend discontinuing the use of progestelle after speaking with your doctor
Again, you should make an appointment to meet with your gynecologist or primary care doctor
in order to review your particular case, including undergoing a breast examination to ensure that there is no mass or other concerning finding. After speaking with your doctor, it may be beneficial to discontinue the use of progestelle and start another agent at his or her discretion, as your symptom of breast enlargement is almost certainly related to your use of this medication.