Month: July 2006

I was prosribed propecia two months ago to have every other day. My hairloss already seems to be beginning to stabilize over this short time. Hopefully I might get some regrowth in the coming months! I was told the 5 alpha reductase reduction with propecia is still just as effective as if I was taking it every day. However I have read elsewhere that you need to take it every day. While I don’t doubt the advice of my medical professional, I have read here, and elsewhere that I need to take it every day to get maximum benefit. Are there two schools of thought as to the appropriate dosage? Or is it that, as the onset of my MBP is very recent my medical advisor is of the view that I would get an effective response on a less frequent dosage. He claims to have many patients who get a good response taking propecial every other day. Thanks for your help

The recommended Propecia dosage is one tablet once a day.

Some doctors may prescribe half a tablet once a day or one tablet every other day, however these are not the official recommended dosages. One reason is that official clinical research has found that the once a day dosing gave the maximum benefit from male pattern hair loss. Another more important reason is that the half life (the time it takes for half of the drug to be eliminated by the body) is only 5 to 6 hours. So theoretically on the days you do not take Propecia, your thinning hair will have no benefit from the drug. You should always follow the advice of your primary doctor and discuss these concerns with him or her, especially before stopping or changing any drug regimen.

A group of experts in the hair restoration field, were polled on the issue of dosing minoxidil and finasteride. What I am quoting below are some unofficial opinions that are not the standard FDA line for these drugs. I present them for the interested readers on this blog. The authors of these thoughts would rather not identify themselves, as these opinions are not in-line with standard treatment recommendations, even for the doctors who believe what is written below…

Comments on minoxidil:

Once a day topical dosing with minoxidil is probably close to, or equivalent to, twice a day. When given orally, minoxidil has a relatively short half like of several hours, but when topically applied, it has a half life of 22 hours in the skin. This makes once a day dosing a very reasonable option which I often suggest to patients.

Comments on finasteride:

Unfortunately, there are no references in the literature, that I am familiar with, concerning the “functional” half like for finasteride.

The serum half life of finasteride is only 4-6 hours. If we assume the worst, 4 hours, then there is far less remaining from a 5 mg dose 48 hours after dosing than there is from a 1 mg dose 24 hours after dosing. Similarly, a 2.5 mg dose does even less well. So, from a simple serum level of finasteride standpoint, every other day 2.5 or 5 would not maintain consistently high enough serum levels.

It gets interesting though when you consider the half life of the finasteride / reductase complex. The half life of this blocked enzyme complex is around 30 days. This is the most likely reason that when you stop taking finasteride (after chronic dosing), it takes 3 months for your DHT levels to return to baseline. This part of the story implies that, once you get up to steady state levels, every other day dosing would surely be enough..

I just think that there might not be enough of the drug around to keep the enzymes saturated using chronic alternate day dosing. These are the reasons that I recommend daily dosing but point out to my patients that it doesn’t matter if you miss a dose now and then.

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