Probably not. First, other than in serial coatings, the technical problems inherent in reliably and reproducably distributing a drug inhomogeneously in a tablet are pretty significant. Why bother unless there is some specific reason? In any case, the flat dose-response curve for finasteride (a little works the same as a lot) combined with the strong binding of the drug to type-2 5-AR probably make the issue moot.

Remember, while the blood half-life of finasteride is only a few hours, becasue binding is essentially irreversible, restoration of type-2 5 AR activity after inhibition requires synthesis of new enzyme, a matter of several days. Back in the days before finasteride became available as 1 mg Propecia, some physicians used to prescribe one Proscar tablet every three days or so. By report, this worked reasonably well.. So even it the drug is inhomogeneuoos (which I seriously doubt), it should make no significance difference, as a practical matter..

Peter H. Proctor, PhD,MD
www.drproctor.com

As I explain elswhere, It is not an easy thing to reliably and reproducably distribute a drug in a tablet inhomogeneously. Likewise, because of the strong binding of finasteride to type-2 5-AR, it probably doesn't make much difference anyway. But if anybody is worried about this, just crush proscar tablets and take what looks to be about one-fifth tablet per day. The flat dose-response curve covers a lot of sins.

As for the persistence of Finasteride-- IIRC, the blood half-life is about 8 hours or so. Considering the flat dose-response curve ( a little works about as well as a lot), you get pharmacologically active amounts in blood for a day or so. However, blood levels are really secondary-- finasteride binds in an essentially non-equilibrium manner to type-2 5-alpha-reductase, strongly and non-diffusibly. That is, once it binds it sticks. Thus, as a practical matter restoration of activity likely strongly depends upon synthesis of new enzyme, a matter of several days.

Peter H. Proctor, PhD,MD

from what i understand finasteride is evenly distributed in a proscar tablet; in the manufacturing process the active ingrediant (finasteride) is mixed with the fillers and binders before the actual pills are "pressed." If the active ingrediant is not evenly distributed, then in theory, a random proscar tablet could have 0 mg of finasteride in it; about 2 years ago I did a google on "active ingrediants being evenly distributed in a pill" and the information I seen seemed to confirm this; also i work in manufacturing, and this engineer I knew worked in a pharmaceutical plant and explained the process and told me that as a general rule the active ingrediant in a tablet is evenly distributed; so I think this can be extrapolated to proscar

You know I have been thinking for sometime now if I should use propecia or proscar but to be honest I'm affraid to use them.
I know you have certain results but I understood that you have might experience a low sexual drive or something similar.
That is an area that I don't wanna mess with
I'm really confused...

Yes, fiansteride (propecia) does have some side-effects. The most distressing of these is arguably decreased libido or sex drive. But the incidence of this in males under 40 years old is less that 5%. How much less is open to debate, but in any case low. Matters are different over age 50, where the incidenc of sclinically-significant sexual dysfunctions is 25% or so. But the drug is not generally recommended for people past their early 40's anyway. In any case, these problems seem to reverse within a few weeks of stopping treatment. I have heard anecdotal stories of a few persons in whom libido dicrease, etc. did not reverse. But htis seems to be rare, if it exists at all.

Peter H. Proctor, PhD,MD

Dr. Proctor, is there any side effects to taking 1 mg of finasteride in your 40's and 50's besides greater incidence of sexual side effects? I perhaps have lost all I'm going to lose as far as hair goes, but prefer to take finasteride in the event I still have more to lose and since it is so inexpensive it is one prescription I can afford to take as long as I have health insurance, it costs me $15.00 a year
Thanks

__________________
My hair is a man made disaster.

As far as Proscar goes!
Is the generic version (besides the shape of the pill) any different at all from the brand name? I would think not since I wouldnt be able to be sold but...it caught me off guard when I filled out my prescription. I dont want to bother my doctor because I probably already know the answer but...anyone?

Dr. Proctor,

..."the incidence of this in males under 40 years old is less than 5%"...

I did not know that. That is fantastic news! Thank you for that. I wish I had know that before. Does this same age to % ratio hold true for erectile dysfunction as well? Regarding the anecdotal stories where libido decrease did not reverse, have you heard the same with respect to erectile dysfunction?

Thank you that was a GREAT statistic which encourages me to try it out.

Also, if propecia is not generally recommended for people past their early 40's, then people who have had ht can not just continue use indefinitely. Don't they run the risk of losing a significant amount of hair in their crown when they hit their 40's then? I was always under the impression that if you have a ht the doctor recommends you stay on propecia indefinitely.

Dr Proctor sez: Good questions. Nobody knows the answers. I will prescribe finasteride up to age 50 or so, after advising the patients accordingly, naturally. Over 40 is a "relative contraindication", mostly because the oldest person in the trial was 41. This seems appropriate most of the time because of the general reversibility of any sexual problems.

Over 50, I start to worry. One reason is the significantly increased incidence of sexual dysfunction. The other is that, while finasteride early may retard the development of prostate cancer, it may promote the progression of the last precancerous stage to frank prostate cancer. As a practical matter, this is probably not an issue under age 50, if it is an issue at all.

Peter H. Proctor, PhD,MD