Can I take 1/2 proscar every 3-4 days?

The key is how much you take in a week. If you take 1/2 of a 5mg Proscar pill. that is like taking 2.5 mg over how say 3 days, almost a full dose. It’s half life is 4-6 hours in the blood stream, but it imbeds in the hair follicle a few weeks and that is when it does its job.