Avodart question

[antonio666]

now i know that avodart claims to stop 92% DHT but is this the case for everyone,i mean presuming that you take the recomended dose of 0.5 a day,would it defintley lower the dht in everyone who used it by 92%
or just some.Does it defintley lower everyones dht by 92% who takes it

can there be variables like 1 person who takes o.5 a day,stops 92%

and the next person who takes the same dose,stops say 65%

 

[antonio666]

somebody must know?

 

[Pondle]

I think it has far less variance in DHT suppression than finasteride - see the chart.

 

[Bryan]

I think it has far less variance in DHT suppression than finasteride...

Looks to me like it has just about the SAME variance in DHT suppression! :wink: I've always wondered why some people have made that claim.

 

[Pondle]

Seems to be no variance at higher doses - I see no whiskers on the chart.

 

[Bryan]

At doses of the two drugs providing equal levels of DHT suppression (which is the only logical way to compare them), the variance appears to be the same.

 

[Pondle]

You could compare equal doses of finasteride and dutasteride and come to the opposite conclusion. Why is that not logical as well? I've seen the greater consistency of suppression achieved by dutasteride compared to finasteride advocated as a selling point by GSK - or at least quotes attributed to GSK on websites.

 

[Bryan]

You could compare equal doses of finasteride and dutasteride and come to the opposite conclusion. Why is that not logical as well?

You mean LITERALLY equal doses of the drug?? Like 1 mg/day of finasteride, and 1 mg/day of dutasteride? What would be logical about that? To make any sense at all, you need to compare doses of the drugs that provide the same average DHT suppression.

I've seen the greater consistency of suppression achieved by dutasteride compared to finasteride advocated as a selling point by GSK - or at least quotes attributed to GSK on websites.

Yes, so have I. And I've been questioning that for a long time, too. I once had a rather protracted discussion of that very issue with Kevin Davis and others way back on alt.baldspot several years ago. I still question the logic of that claim.

 

[Old Baldy]

Bryan and Pondle: You're both going over my head.

Could either of you explain how someone can tell if there is less or more variance using dutasteride. based on the chart Pondle has posted?

I've seen that chart alot but don't understand how you can tell, either way, what any variance might be?

I mean, how does that chart show some people respond differently to the same dose of, let's say, dutasteride.? Doesn't the chart provide averages?

I'm sorry, but I'm just not understanding this one.

 

[Pondle]

Bryan and Pondle: You're both going over my head.

Could either of you explain how someone can tell if there is less or more variance using dutasteride. based on the chart Pondle has posted?

I've seen that chart alot but don't understand how you can tell, either way, what any variance might be?

I mean, how does that chart show some people respond differently to the same dose of, let's say, dutasteride.? Doesn't the chart provide averages?

I'm sorry, but I'm just not understanding this one.

My interpretation of the chart is that in a sample of men taking 5mg/day finasteride, DHT suppression varies between about 55% and about 85% (see the purple whiskers on the chart) but the mean DHT suppression in the sample is 70% (see where the purple box is).

However, for a sample of men taking taking >0.5mg/day dutasteride, the DHT suppression is always >90% (there are no whiskers around the green boxes representing 0.5mg, 2.5mg or 5mg of dutasteride).

 

[Bryan]

Bryan and Pondle: You're both going over my head.

Could either of you explain how someone can tell if there is less or more variance using dutasteride. based on the chart Pondle has posted?

I've seen that chart alot but don't understand how you can tell, either way, what any variance might be?

I mean, how does that chart show some people respond differently to the same dose of, let's say, dutasteride.? Doesn't the chart provide averages?

The chart provides averages, but it also gives a measure of variance by providing those statistical brackets around the averages at certain points on the graph. For example, the chart show that at a dose of 5 mg/day, finasteride provides an average 70% DHT reduction; however, the purple bracket that extends above and below the 70% figure shows that if you tested it on a whole bunch of people, 95% of those people would be expected to fall within a range that extended from about a little over 50% (the top of the bracket) to what looks like a little over 85% (the bottom of the bracket).

Keep in mind here that I have only a bird's-eye-view of statistics, so I might be off on some of the details. For example, I'm assuming that those brackets signify 95% confidence intervals, but they might be something else (maybe 90% intervals, or whatever). But you get the general idea of what they mean. If there are any statistics experts here who want to correct me or elaborate on what I said, please feel free to do so!

 

[Guest]

For example, I'm assuming that those brackets signify 95% confidence intervals, but they might be something else (maybe 90% intervals, or whatever).

safe assumption. most confidence intervals are calculated at 95% and not 90% or 99.5% or whatever

 

[Bryan]

My interpretation of the chart is that in a sample of men taking 5mg/day finasteride, DHT suppression varies between about 55% and about 85% (see the purple whiskers on the chart) but the mean DHT suppression in the sample is 70% (see where the purple box is).

However, for a sample of men taking taking >0.5mg/day dutasteride, the DHT suppression is always >90% (there are no whiskers around the green boxes representing 0.5mg, 2.5mg or 5mg of dutasteride).

But Pondle, you have to be reasonable about it! If you were to take a huge dose of dutasteride that was sufficient to almost completely suppress DHT, just how much variation would you EXPECT?? Say, for example, that you took 10 mg/day, which (let's say for the sake of argument) would reduce it by an average of 98%. OF COURSE that would produce only a very minimal variation, because that average 98% could only go to 100% for a maximum at the high end, and it's obviously not going to drop by very much at the low end (maybe to 95% or so, at the lowest). But what does THAT tell us? That information isn't anything unexpected, and neither is it useful for anything.

What IS very useful to know is how the two drugs would compare when you adjust the doses to about the same level of DHT suppression. That's the only thing that would make any sense. And we see from the graph that when we use a dose of 0.05 mg/day of dutasteride, both the DHT suppression AND the variance are about the same as what you have when you use 5 mg/day of finasteride (a dose of 0.1 mg/day of dutasteride would be almost exactly the same as the finasteride). In that all-important sense, it looks to me like dutasteride and finasteride have about the same level of variance.

 

[Pondle]

My expectation would be that 0.5mg/day dutasteride might have produced variation between say, 80 and 100% suppression or something, with a mean of 90. Granted the closer the mean comes to 100% the less scope for variation. After all no-one can have >100% suppression!

 

[Bryan]

But you get the main point I'm making, right?

 

[Guest]

Bryan, I thought the number is 98.5% 5ar2 inhibition on 0.5 mg dutasteride. That's what we've always thrown around and not this low 90s number. Or are we talking total percentage of 5ar inhibited, so we're taking 5ar1 into account as well when calculating?

Either way, we should probably be focusing more on 5ar2 since by all indications it's like 50 times more important than 5ar1 when it comes to hair loss. And dutasteride clearly spanks finasteride when it comes to inhibiting 5ar2.

 

[Bryan]

Bryan, I thought the number is 98.5% 5ar2 inhibition on 0.5 mg dutasteride. That's what we've always thrown around and not this low 90s number. Or are we talking total percentage of 5ar inhibited, so we're taking 5ar1 into account as well when calculating?

I was talking total serum DHT.

 

[Pondle]

But you get the main point I'm making, right?

Yep - you're looking at the suppression range achieved for a given mean suppression (by either drug). I'm looking at the suppression range for a given dose.