Another finasteride graph for you to examine

[Bryan]

About a month or so ago I exchanged a couple of replies with another poster (don't even remember for sure now who it was) who seemed to think that it was a bad idea to take finasteride every other day because if you do, it would make for inconsistent blood levels of the drug and (by logical extension) fluctuating levels of DHT. I tried to explain to him that even when you DO take finasteride on a daily basis, the blood level of the drug still fluctuates over a wide range, but he didn't seem to buy it. I made a mental note to myself to post a scan of a graph from the Gisleskog et al studies on finasteride and dutasteride which shows eactly what I'm talking about, and I finally got around to it just now. The graph is below.

Please note that the scale used in that graph is exponential, so the blood level of finasteride drops even more over a period of 24 hours than it may appear at first glance. Keeping that in mind, everybody can see that there is at least an order of magnitude difference between the peak blood level of finasteride that you get shortly after you take a dose of finasteride (a Proscar dosage, in this case) and the lowest level that you have shortly before you take the next day's dose. So finasteride doesn't build-up in the bloodstream to anywhere nearly the same extent that dutasteride does, which is one of the reasons that dutasteride ends up being considerably more powerful than finasteride, with regular use.

 

[pratc]

Interesting.

Would I be correct in thinking that the reduction in DHT concentration would produce a fairly level graph (using the same x axis as the graph shown) even though the finasteride concentration various considerably over the 24 h period? I ask because it has been said that, for a 1mg dose, 'Finasteride produces a rapid reduction in serum DHT concentration, reaching 65% suppression within 24 hours.' I believe the suppression (eventually) is more than 65% for a 1 mg dose so the word 'reaching' implied it hadn't reached its maximum and therefore it would be a fairly level graph with continued 1 mg doses.
Thanks.

 

[Bryan]

Would I be correct in thinking that the reduction in DHT concentration would produce a fairly level graph (using the same x axis as the graph shown) even though the finasteride concentration various considerably over the 24 h period?

Yes. Absolutely. You may not have seen this earlier graph which I and others have posted many times over the years:

http://www.geocities.com/bryan50001/graph8.htm

It shows that even after various SINGLE doses of finasteride, DHT levels only slowly rise back up over the next few days, despite the fact that finasteride is almost completely out of the system after only a day or two. The reason for that is that the type 2 enzyme which finasteride inhibits only slowly regenerates. So the bottom-line is that finasteride levels in the blood fluctuate wildly up-and-down with daily dosing, but DHT levels still stay relatively level.

 

[pratc]

Bryan,

Thank you for the explanation.