As they have different mechanisms to promote hair growth, it's difficult to compare them. Minoxidil is a vasodilator used to expand blood vessels and boost blood flow to the scalp in order to stimulate hair growth. Both minoxidil and Redensyl are research-backed treatments, and their effects on hair growth were demonstrated in clinical studies. However, compared to Redensyl, minoxidil is an FDA-approved treatment and has been subjected to more trials.