Testosterone Replacement Therapy and Hair Loss

Hello Dr. Rassman,
I am 40 years old, male. I have been on presription testosterone replacement therapy for about 1.5 years, due to chronically low levels of total and free testoserone. My doses are physiological (about 100mg/week). I have always had a very thick head of hair — and no MPB or baldness of any kind on either side of my family as far back as any generation can remember. I never experienced any hair loss or thinning until about 1 month ago, when I started noticing my hair suddenly started falling out in the shower and when I combed it, at the hairline, top of the head. It has become very visibly thinner in the past month. I have had every test my doctor could think of (blood, glands, brain scan, etc.), and he has ruled out pretty much everything he can think of. He started me on .5mg daily of Avodart (yes, I know – off label use, but he has seen great results with it over the last 3 years with his patients), but I have been on it for only a month. My doctor says that as long as I am on Avodart, even if the testosterone is causing the rapid hair thinning and loss, then this will stop it. He suggested that I do not stop TRT. My questions are:

1. Do you think that these testosterone injections can cause hair loss to suddenly occur after almost 2 years with no previous problems; and
2. Do you think that, assuming it is the testosterone that is causing the hair thinning/loss, that I can continue on TRT without further hair loss, provided I stay on Avodart?

Thanks you for your help on this one!

Yes, testosterone replacement therapy can cause hair loss. Some people have the gene for hair loss that has not been expressed for a few generations. Testosterone can precipitate the gene’s expression. Some people believe that testosterone itself can cause you to lose hair.

With regard to your second question, Avodart will help block the effect on DHT receptors, but there is clearly a direct effect of testosterone on the gene as well, particularly if higher levels are achieved. Time will tell you.

I would get immediate mapping of your scalp hair for miniaturization to put some measurement to the process that you are observing. There is no substitute for good measurements to find out what is actually going on.