Taking Half a Propecia (0.5mg Finasteride) Twice Daily?

If the half-life of finasteride is 4 to 5 hours, wouldn’t it be better to split the 1mg propecia pill in two, and take one in the morning, and one in the evening?

The half life of finasteride is 4.5 hours. This means that in 4.5 hours, serum levels of finasteride drop to the half of its original level, but the tissue levels will last longer than the serum levels. Finasteride blocks the effect of the enzyme 5-alpha-reductase, and the effects of the medication due to the blocking of this enzyme is actually much longer and can last up to a few days. On the other hands, the body can eliminate the finasteride, but the pharmacological effects of the medication persist long after.

Considering long lasting pharmacological effects of finasteride, taking it on a more frequent basis probably does not make any difference in its final results.