Ask the doctor: Do statins cause hair loss?

Q. My hair's been thinning. Could it be due to simvastatin, which I started taking several months ago?

A. Hair loss, or alopecia, is a very rare side effect of all statin drugs. Widely prescribed in the treatment of high cholesterol, statins work by blocking the action of an enzyme the liver uses to make cholesterol. About 1% of people taking statins report hair loss. This figure hasn't changed since 1987, when statins were introduced. We don't know exactly why statins might cause hair loss. But we do know that cholesterol is an important building block for steroid hormones, which play a role in hair growth.