Anastrozole and Propecia

Hi doc! Thank you for your excellent and informative blog! I’ve been hearing things recently about using the very potent aromatase inhibitor anastrozole to prevent the ‘estrogenic’ side effects of finasteride. Anastrozole drastically reduces estrogen levels in men and, unsurprisingly, raises free testosterone as well. Would you be comfortable with one of your patients adding anastrozole (‘Arimidex’) to his propecia regimen, or would you see this is opening up a whole other ‘can of worms’, and potentially serious side effects?

Arimidex (anastrozole) is a anti-breast cancer medication for post menopausal women. There are no clinical trials in men. You would basically be experimenting with your body without any knowledge of the consequences. I would recommend against this. Especially since I’ve seen the complaints/worries people have about side effects from Propecia, you would be just adding fuel to the fire.

According to the Arimidex website, some of the most common side effects seen with the drug include, “hot flashes, joint symptoms (including arthritis and arthralgia), weakness, mood changes, pain, back pain, sore throat, nausea and vomiting, rash, depression, high blood pressure, osteoporosis, fractures, swelling of arms/legs, insomnia, and headache”. Also, a less common side effect of Arimidex is hair loss.