Almost anyone who takes 5α-reductase inhibitors to reduce dihydrotestosterone levels (and treat hair loss) chooses either:
- Finasteride (1 mg/day; brand name Propecia). Or,
- Dutasteride (0.5mg/day; brand name Avodart).
I have discussed the dosage and efficacy of both Finasteride and Dutasteride in lengthy detail in the past. Most people take either 1mg Finasteride per day or 0.5mg Dutasteride per day to treat their hair loss.
While Dutasteride inhibits all three isoforms of 5α-reductase (types I, II, and III), Finasteride only inhibits the type II and III isoforms of the enzyme. Dutasteride inhibits a significantly greater percentage of dihydrotestosterone (DHT) in comparison to Finasteride.
Taking Both Finasteride and Dutasteride to Treat Hair Loss
A few years ago, one of this blog’s frequent commentators mentioned taking Finasteride for six days a week and the much stronger Dutasteride for one day a week. This would theoretically limit the side effects from taking the much more potent Dutasteride for all seven days of the week.
I blew off this idea as pointless, since Dutasteride by itself has such a long 5-week half-life (Finasteride has a 6-hr or so half-life). So one might as well just take Dutasteride once or twice a week and completely ignore taking Finasteride to keep things simple. In fact I myself have been taking 0.5mg Dutasteride every two days rather than daily for a couple of years now.
However, a short time after the above commentator made the suggestion, another blog reader made the following comment:
DECEMBER 8, 2016 AT 2:58 PM
I have just been advised by a hair transplant surgeon, that if you combine 1mg finasteride daily with 0.5mg dutasteride once a week, you can expect regrowth. He learnt this from a recent conference he attended. A hair specialist presented a paper which showed good results from combining finasteride regularly with just one capsule of dutasteride per week on top. I’m yet to try this, but am willing to give it a go and just stop the dutasteride if there is no change or bad side effects.
And then yet again, someone else made the below comment last year:
FEBRUARY 8, 2018 AT 6:20 AM
I had been on Propecia alone for 15 years. Noticed hair started to thin again in 2016. Added Avodart in Jan 2017 and I can honestly say my hair is better and thicker than all the years on just Propecia. I take Propecia every day and one 0.5 Avodart once a week. Never had any sides at all. I did have a shed when I added the Avodart, but stick with it and within about 4 months I could feel and see new hairs. My hairline is better than I can remember. It has taken one full year of this dosage to fully appreciate just how effective it has been. I will continue until things change and then reassess, but hopefully that won’t be for a very long time.
Combination Therapy: Finasteride and Low-Dose Dutasteride
While doing research for this post, I came across a 2013 study from Australia that found combination treatment on one male patient quite effective. Finasteride by itself was not working for him, but adding 0.5 mg Dutasteride once per week drastically improved the hair growth results. Before and after photos can be seen in the study.