Would You Say That 2.5mg dutasteride Is More Effective Than 0.5mg dutasteride

[Michael1986]

2.5mg dutasteride was shown to grow more hair than 0.5mg dutasteride in the Glaxo phase 2 trial. After six months of treatment, the mean hair count compared to baseline was 109.8 for 2.5mg, while it was 95.5 for 0.5mg.

However, hair counts peaked earlier, and levelled off earlier, at the higher dose, as shown by the mean hair counts after three months in the same study (100.4 for 2.5mg, 71.9 for 0.5mg). The increase in hair counts between 3 months and 6 months was much greater for 0.5mg than for 2.5mg.

Dutasteride has a five-week half-life, and so the drug would have built up in the system much quicker at the 2.5mg dose than the 0.5mg dose, and this could be the reason why hair counts on 2.5mg were shown to be greater in this study. It might be that 2.5mg is actually not more effective than 0.5mg, but rather that it just builds up in the system quicker and therefore causes hair counts to peak earlier. After all, there is essentially no difference in the level of inhibition of the DHT from 5ar type 2 between these two doses once they have built up to a steady state in the bloodstream. They both inhibit essentially 100% of this DHT. The only difference is that 2.5mg inhibits a lot more of the DHT from 5ar type 1, and the DHT from this enzyme is believed not to play much of a role at all in hair loss.

If this trial had gone on longer, my assumption is that the hair count difference between these two dosages would have got less over time.

So, this being said, would you say that 2.5mg dutasteride is actually a more effective treatment than 0.5mg? Is there much point in increasing your dutasteride dosage above 0.5mg in an attempt to get better results?

 

[Who Farted]

It tells you right there that there isn’t evidence to support the assertion that the higher dose is objectively better. If what is written here accurately reflects the study then your assumption is correct and the gap would have closed given more time.

Assuming that you are a responding to .5mg upping it wouldn’t buy you anything except reaching peak hair growth slightly faster and subjecting you to a much greater chance of side effects.

It would also decrease the amount of time the medication would work for you. If you start at .5mg you can adjust the dosage upward more times to negate your body adjusting to it then you could if you start at 2.5mg. Getting slightly more hair slightly faster isn’t worth sacrificing years of longevity.

 

[Michael1986]

It tells you right there that there isn’t evidence to support the assertion that the higher dose is objectively better. If what is written here accurately reflects the study then your assumption is correct and the gap would have closed given more time.

Assuming that you are a responding to .5mg upping it wouldn’t buy you anything except reaching peak hair growth slightly faster and subjecting you to a much greater chance of side effects.

It would also decrease the amount of time the medication would work for you. If you start at .5mg you can adjust the dosage upward more times to negate your body adjusting to it then you could if you start at 2.5mg. Getting slightly more hair slightly faster isn’t worth sacrificing years of longevity.

Thank you for your response.

Yeah I think it is fairly obvious that the gap would have closed had the study gone on longer. You say that the 2.5mg dose would have a much higher chance of side-effects than 0.5mg. That would be because the higher dose removes significantly more DHT from 5ar type 1, right?

Has it been indicated in studies that a higher dose of dutasteride will work for a shorter period of time than a lower dose will? Assuming there is such a thing as your body adjusting to the dose over time, and that this adjustment takes place more quickly at higher doses, I'm just trying to work out how this might be in view of the fact that it is presumably not the dosage of dutasteride itself but rather the resultant amount of DHT inhibition which determines the speed of this adjustment process, and there is only a very small difference in the overall amount of DHT inhibition between 0.5mg and 2.5mg of dutasteride. According to a study that was done, it is about 94% inhibition of total serum DHT at 0.5mg, and about 97% at 2.5mg.

 

[Who Farted]

I think it comes down to how sensitive you are to DHT; a lower sensitivity would allow the lower dose to work, high sensitivity requires a higher dose to do the same thing, but the ceiling of the effect is the same for both.

When I say ceiling, I mean the point at which all of your follicles are protected from a given DHT sensitivity. That is the end result of treatment and there is no way to improve on it.

In other words, once you reach a dose that stabilizes your hair there is no reason to take anymore as you will have achieved the best possible result.

I’m honestly not sure this has been studied or confirmed to be the case with dutasteride, but it seems likely that it is given that it shares the same result ceiling as finasteride.