Why would Avodart work better?

[Siberian]

I've always read that Merck dosed finasteride at 1mg per day because they found no significant increase in effectiveness (regarding hair loss) at higher dosages. Supposedly, although we know Proscar, at 5mg, reduced DHT (70%) even more than Propecia at 1mg (55%), Proscar is no better at fighting hair loss than Propecia.

But why then would Avodart work better than Propecia? The only difference is that Avodart lowers DHT (90%) beyond that of even Proscar. But according to Merck, it would seem that lowering DHT beyond Propecia levels just doesn't matter.

So why then is Avodart more effective?

 

[Aplunk1]

I'm going to try to make this as short as possible.

Avodart inhibits both types of 5AR enzymes, whereas Propecia only inhibits Type II. This automatically reduces more DHT in the system than Propecia.

Secondly, the amount of Type II 5AR reduced by Avodart is STILL MUCH GREATER than the amount reduced by Propecia.

Although nobody really knows whether reducing Type I will affect hairloss, the fact that Avodart reduces more of Type II 5AR enzyme basically suggests that it will perform better than Propecia.

I know this is confusing. It's the best way I could put it... semi-under the influence.

 

[Peter2]

Secondly, the amount of Type II 5AR reduced by Avodart is STILL MUCH GREATER than the amount reduced by Propecia.

And this is very important, the type II 5AR enzymes are in large quantities located in the dermal papilla cells and also in the prostate tissue.

 

[Slartibartfast]

...although we know Proscar, at 5mg, reduced DHT (70%) even more than Propecia at 1mg (55%), Proscar is no better at fighting hair loss than Propecia.

I don't think the difference in reduction of serum DHT between a 1mg and 5mg dose of Finasteride is so great. This is from memory, so someone correct me if I'm way out, but isn't it more like 68% for 1mg and 70% for the 5mg dose.

 

[Anderz]

...although we know Proscar, at 5mg, reduced DHT (70%) even more than Propecia at 1mg (55%), Proscar is no better at fighting hair loss than Propecia.

I don't think the difference in reduction of serum DHT between a 1mg and 5mg dose of Finasteride is so great. This is from memory, so someone correct me if I'm way out, but isn't it more like 68% for 1mg and 70% for the 5mg dose.

Agree.

 

[IDOASIS]

...although we know Proscar, at 5mg, reduced DHT (70%) even more than Propecia at 1mg (55%), Proscar is no better at fighting hair loss than Propecia.

I don't think the difference in reduction of serum DHT between a 1mg and 5mg dose of Finasteride is so great. This is from memory, so someone correct me if I'm way out, but isn't it more like 68% for 1mg and 70% for the 5mg dose.

Agree.

Don't agree.
the different between 1 mg finasteride to 5 mg in body DHT will be 68.7% and 69.2% ,but it is not the different between the scalp DHT :!:
Look at the different between the haircount, increase of 77 Vs 95 for one inch circle.

http://www.hairlosstalk.com/download/finmicro.pdf

Another example ,

0.5mg Dutasteride inhibits ~ 92% serum DHT and 55% scalp DHT
2.5mg Dutasteride inhibits ~ 95% serum DHT and 82% scalp DHT
http://hairsite2.com/library/article226.htm

In this case there is a slight different between the the body DHT,but look at the huge different between scalp DHT.

 

[Slartibartfast]

This figure of a .5mg Dutasteride dose resulting in a 55% decrease in scalp DHT appears quite frequently. It tends to go something like this (from July of 05):

Dutasteride levels: 90% serem, 55% scalp
Finasteride equiv: 70% serem, 38% scalp.

I seem to remember Bryan talking about these figures and how another, contradictory study demonstrated that scalp and serum DHT levels decrease by broadly similar amounts - in percentage terms.

Exactly. Those specific numbers Sam quoted don't mean diddly-squat.

Bryan

Perhaps people should read the 55% figure for dutasteride in tandem with the 38% figure for finasteride (quoted above), as they presumably came from the same study. Yet in the case of Finasteride this research is more often quoted:

"The effects of finasteride on scalp skin and serum androgen levels in men with androgenetic alopecia"

University of Oklahoma Health Sciences, Oklahoma City, USA.

...OBJECTIVE: We attempted to determine the effect of finasteride on scalp skin and serum androgens. METHODS: Men with androgenetic alopecia (N = 249) underwent scalp biopsies before and after receiving 0.01, 0.05, 0.2, 1, or 5 mg daily of finasteride or placebo for 42 days. RESULTS: Scalp skin DHT levels declined significantly by 13.0% with placebo and by 14.9%, 61.6%, 56. 5%, 64.1%, and 69.4% with 0.01, 0.05, 0.2, 1, and 5 mg doses of finasteride, respectively. Serum DHT levels declined significantly (P <.001) by 49.5%, 68.6%, 71.4%, and 72.2% in the 0.05, 0.2, 1, and 5 mg finasteride treatment groups, respectively."

It seems illogical to say that .5mg of dutasteride reduces serum DHT by significantly more than finasteride, yet lowers scalp DHT by significantly less than it. This is particularly strange given dutasteride's out-performance of finasteride in hair count studies and so I'll treat the 55% figure with some suspicion.

Slarti