Can testosterone replacement therapy, such as testosterone gel, cause hair loss?

Yes: Exogenous testosterone can be broken down in the body to a more potent form of the hormone called dihydrotestosterone or dht. Dht can cause hair follicles on the scalp to weaken or shrink causing alopecia (hair loss).

Propecia (finasteride): After Proscar was introduced for benign prostatic hypertrophy, many physicians reported hair regrowth in patients being treated with the drug. The manufacturer later introduced propecia, (finasteride) or Finasteride in a one milligram tablet with an fda approval for male pattern baldness. It works by decreasing testoserone conversion to dht. Ask your doctor to rx. Proscar and quarter the tabs, as it is covered.

Yes: Hair loss is a result of the effects of breakdown products of testosterone notably Dht but the most recent information shows that prostaglandin d2 is the true culprit. Increase circulating testosterone and you get more of the breakown products that cause baldness. Castration which eliminates testosterone prevents baldness in men.

Yes - Check DHT: Before starting testosterone replacement, check your Dht (and estradiol) level. Then whenever you check your testosterone level (you do do that, right?), you can also check your Dht (and estradiol) level and see if it's increased enough to put you at risk for hair loss (and prostate enlargement). Sometimes, just by adjusting your dosing, you can get around this issue w/o taking add'l medication.