I'm not sure if rubbing oestrogen into the breasts is a good idea. Breast cancer is often stimulated by oestrogen and rubbing it directly onto the breasts might increase the risks.
There is no medical evidence that rubbing Oestrogel directly into the breast causes cancer. I have my blood and lipids checked every 6 months, I have had a mammogram and all is clear with me. I have been rubbing gel into my breasts for 10 years now and it has definitely aided my breast growth. My doctor monitors me closely as I have had a DVT in the past. Is the reason I don't take my script orally.