In cases where lowering the DHT level beyond what finasteride is capable of is indicated, we use Dutasteride instead of increasing the Finasteride dose beyond 0.2mg. At and above 0.2mg, Finasteride does not lower blood DHT levels much above 70%.* A study showed that Dutasteride lowers DHT level as much as 90%.** This is well beyond the capabilities of Finasteride which maxes out around 70%. Oral Dutasteride is ideal for men who want to try something stronger than Finasteride. A study showed that oral Dutasteride both increases hair count and increases hair thickness significantly more than Finasteride***. While Dutasteride will have greater risk of sexual side effects in men over 0.2mg Finasteride, the vast majority of men will not have these side effects and tolerate it very well. In fact, a study showed similar rates of sexual side effects (around 2-3%) in men taking Dutasteride as men taking Finasteride. For this reason, we prefer the use of oral Dutasteride over oral Finasteride for men who want a stronger option than 0.2mg oral Finasteride. Another use of oral Dutasteride is for women. Female pattern hair loss tends to respond better to Dutasteride than Finasteride. A study found that an increase in hair thickness was seen more with women taking Dutasteride than Finasteride.**** The same study also found that Dutasteride performed statistically significantly better than finasteride in the age category below 50 years at the central and vertex sites of the scalp. Another study found no reports of sexual side effects in women taking Dutasteride for hair loss.***** It should be noted that women who are pregnant, breastfeeding, or planning to become pregnant should not be taking Finasteride or Dutasteride as it can cause birth defects in a male fetus. Pre-menopausal women taking these medications should use proper birth control, and stop taking them immediately if becoming pregnant.
* Drake, L et al. “The effects of finasteride on scalp skin and serum androgen levels in men with androgenetic alopecia.” Journal of the American Academy of Dermatology vol. 41,4 (1999): 550-4.
** Olsen, Elise A et al. “The importance of dual 5alpha-reductase inhibition in the treatment of male pattern hair loss: results of a randomized placebo-controlled study of dutasteride versus finasteride.” Journal of the American Academy of Dermatology vol. 55,6 (2006): 1014-23. doi:10.1016/j.jaad.2006.05.007
** Olsen, Elise A et al. “The importance of dual 5alpha-reductase inhibition in the treatment of male pattern hair loss: results of a randomized placebo-controlled study of dutasteride versus finasteride.” Journal of the American Academy of Dermatology vol. 55,6 (2006): 1014-23. doi:10.1016/j.jaad.2006.05.007
*** Gubelin Harcha, Walter et al. “A randomized, active- and placebo-controlled study of the efficacy and safety of different doses of dutasteride versus placebo and finasteride in the treatment of male subjects with androgenetic alopecia.” Journal of the American Academy of Dermatology vol. 70,3 (2014): 489-498.e3. doi:10.1016/j.jaad.2013.10.049
**** Boersma, Ids H et al. “The effectiveness of finasteride and dutasteride used for 3 years in women with androgenetic alopecia.” Indian journal of dermatology, venereology and leprology vol. 80,6 (2014): 521-5. doi:10.4103/0378-6323.144162
***** Seale, Lauren R et al. “Side Effects Related to 5 α-Reductase Inhibitor Treatment of Hair Loss in Women: A Review.” Journal of drugs in dermatology : JDD vol. 15,4 (2016): 414-9.