The role of 5 alpha redutase inhibitors on Body Hair Transplantation

The pathway that leads to the production of the 3 androgens(DHT, testosterone and Androstenedione, also has a route that leads to theproduction of Estrogen). When you block DHT production by 5AR inhibition, thepath to testosterone and/or estrogen production tends to be upregulated. The degree to which either of these two hormones (testosterone and Estrogen) areaffected by 5AR inhibition should depend on several factors including thepatient’s idiosyncratic predispositions, drug dosage, drug type and actions (egDutasteride blocks both 5AR-1 and 5AR-2 hence leaves less room for DHTproduction via the 5AR1 pathway -the case with finateride) etc.

In healthy individuals, most body hair (relevant to BHT) responds especially totestosterone positively. Hence if DHT blockage results in more testosteroneproduction than estrogen, you may actually end up with a positive effect onbody hair than in premedication periods. If however, more estrogen is producedthan is testosterone, you may well have a slowing of body hair growth and/orbreast enlargement and/or loss of libido etc. If these hormones (Testosteroneand and Estrogen) are raised to the same degree activity-wise, then you mayhave no change in body hair status as the effects of the 2 will balance out (mostpatients on alopecia reduction doses). This is the basis for my previousstatement “Some activities of 5AR inhibitors (dutasteride and finasteride)are not a direct result of DHT or lack of it” found in the post you pastedabove. As you can judge from the aforementioned, some activities of 5ARinhibitors is as a direct result of Testosterone and/or estrogen upregulation,rather than DHT.

A study on chest hair suggests that when slowing of hair growth occurs withfinasteride use, it sustains for about 6 months following which it ceases toaffect it either way as evidenced by observations in months 6 through 12. It isbelieved that even in these cases, the effect of testosterone increases tobalance the intial estrogenic burst that may have occured in the earliermonths. Also these uncommon negative effects tends to reverse with cessation of meds.

Please note: All the studies leading to the aforementioned statements have been based on prostate studies whereby higher doses of 5AR inhibitors are used compared to the standard doses for hair loss indications.

Conclusion:

As stated in an earlier post: I do not generally dissuade my patients fromusing finasteride or dutasteride post-BHT, but certain caveats have applied. Ihave thus far advised caution in the following events:

1. Breast symptoms have occurred and persist.
2. Libido problems have occurred and persist.
3. 5AR inhibitors have been used for less than 6 months.
4. I pay special attention to the use of dutasteride (an effective 5AR-1 and5AR-2 inhibitor), and patients using higher doses (of either meds) than is thestandard recommendation for hair loss treatment.
5. I have also re-emphasized pre-operative wet shaving and the intra-operativeselection of only actively growing body hair for transfer. These would constitute anagen hair that has weathered any real or imagined negative effectsof any agent the patient may have been using.

I find these guidelines prudent to follow pending further evidence thatwarrants refining them.

So to the question, CAN 5AR inhibitors cause reduced body hair…yes. Should this pose a cause for concern as to the future of BHT in MPB? Likely not. The problem may occur in a minority of predisposed men, when it does, it is notsustained pass 6 months.

Incidentally, I have seen challenges from either side of the BHT argument for the other side to point to a study that proves or disproves a point. It just so happens that in the BHT practitioners of today lays the best chance if any of such studies happening. Most branches of medicine will have little incentive tomonitor the effect of finasteride / dutasteride on BHT in healthy men to theextent that would satisfy our scrutiny.