Taking Propecia for Hair Loss Every Other Day?

Mon 29 Sep 2008

This insightful hair loss information was posted on our hair restoration forum by Dr. Jerry Cooley of Charlotte, NC who is a member of the Coalition of Independent Hair Restoration Physicians.

Propecia is approved by the US FDA for once a day use for hair loss. This does not mean it is the best dosage, only the one that was studied and approved. The average serum “half-life” of finasteride 1mg is about 5 hours in young men and 8 hours in older men. This does not mean that half of the medicine is out of your body in that time period though. The finasteride molecule is distributed throughout the body where it binds to the type II 5-alpha-reductase enzyme, thereby inhibiting conversion of testosterone to dihydrotesterone (DHT). Serum DHT is reduced about 65%, and less DHT means less balding. But several studies show that a single dose of finasteride suppresses serum DHT for 7 days or more (Eur J Drug Metab Pharmacokinet. 1991 Jan-Mar;16(1):15-21, J Clin Endocrinol Metab. 1990 Apr;70(4):1136-41, Prostate. 1989;14(1):45-53). So the finasteride is leaving the bloodstream, entering the tissue throughout the body, and binding to the type II 5AR (5-alpha-reductase) enzyme, resulting in long lasting DHT suppression.

I do not “recommend” my patients take finasteride daily, every other day, twice weekly, etc. Rather I feel it is my duty as their doctor to advise them of the known facts about this medication. Most of my hair loss patients choose to take it on a Mon-Wed-Fri schedule, which is rational from my point of view. Many of my younger patients take it daily ‘just to be sure’ while my older patients are happy to take it two or three times a week. There are no clinical studies showing that less than daily dosing is as effective to treat baldness as daily dosing and for obvious financial reasons, the pharmaceutical company making finasteride has no incentive to fund such a study.

I hope this information is helpful. It is up to each patient to make an informed decision about which dosage is right for them.  

Dr. Jerry Cooley

Associate Publisher of the Hair Transplant Network and the Hair Loss Learning Center
View my Hair Loss Weblog

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6 Comments so far:

  1. timallen45 says:

    Hello, thanks for the informative article!
    I’m wondering if reducing the dosage to a Mon-Wed-Fri schedule removes all side effects? The only way to know is to speak to Dr. Cooley and ask him what his patients are saying?

  2. Tim,

    Lowering the dosage of finasteride doesn’t necessarily guarantee you won’t experience any side effects from Propecia. But I imagine at the very least, they may be reduced. You may want to contact Dr. Jerry Cooley directly for his professional input.

    Best wishes,

    Bill Seemiller
    Managing Publisher of this Community

  3. Arjun says:

    Is it true that usage of 1 mg finasteride has irreversible side-effects? If yes, does this medicine have any replacement, except for minioxil.

  4. Arjun,

    From what I’ve gathered, the side effects (sexual or not) from finasteride/Propecia should subside once you stop taking the medication and the compound is flushed from your system. Although there are alternative medications (like minoxidil), nothing else, to my knowledge, is going to work like finasteride (stopping the conversion of testosterone to dihydrotestosterone – the chemical that causes hair loss)without actually containing finasteride.

    Hope this helps!

    Blake (Future_HT_Doc)

  5. Amandeep says:

    I’ve been experiencing brain fog from propecia. I’ve only been using it for two weeks and was wondering if lowering the dosage would help? Also do sides go away after continued use? In other words does the body adjust to the drug or is it best if I quit while I’m ahead?

  6. David aka - TakingthePlunge says:


    It’s best to have this discussion with your prescribing physician. I’m not a doctor and my comments should not be taken as medical advice. However, I can tell you that some men who experience side effects from Propecia choose to lower their dosage before quitting the drug entirely. This can be done by cutting the tablets or staggering the days that you take the pill.

    It’s also been suggested that starting with a very low dose and then gradually increasing it to 1mg per day may be a good way to get your body used to it.

    Ultimately, you and your physician should agree on how to proceed from here.


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