MINOXIDIL

Minoxidil is a vasodilator. It is basically a prodrug. It is converted to an active metabolite in the body which is an opener of potassium channels. It causes relaxation of arteriolar smooth muscles with little effect on venous vessels. It increase hair growth by following mechanism:
Alteration of androgen effect on genetically programmed hair follicle
Enhanced microcirculation around hair follicles
stimulation of resting hair follicles
It is applied topically in different strength ( 2 %, 4%). It is indicated in male pattern baldness & alopecia areata. It should be applied for at lest two months for adequate response. Side effects are headache, dizziness, itching & burning sensation.