It may be possible, but I dont think that it's permanent.
This is my deduction...some people who dont have the expressive gene for MPB or who have a low affinity for the 5 alpha-reductase enzyme will not have their testosterone metabolized into DHT, which can minituarize the hair follicle and shaft, creating a thinner hair in diameter.
If that person is using a fair dose(500mgs) or d-bol and not using an aromatase inhibitor than a fair amount of test will metabolize into estrogen. This will result in noticeably thicker hair shafts, as seen infemales most have thick hair and smooth skin.
However once exogenous test is eliminated and estrogen levels decline to homeostatis, then I think that the hair texture will return to normal.
Keep me posted as to how long your friend has been off test, including HCG,tamoxifen, and clomid, as these can increase estrogen in certain areas, as well as his hair density a few months down the road.
B32