Happy Head is a liquid that comes with a calibrated dropper. You can line up the dropper directly onto your scalp and apply the solution for an easy, mess-free application. Dr. Behnam chose a liquid due to the problems with both spray and gel solutions for hair growth. In spray formulations, the hair traps the mist and prevents the actual medication from reaching the scalp, thus limiting the result significantly. Also, sprays limit how much you will apply on the scalp.