Minoxidil

Minoxidil is one of two FDA-approved treatments for male pattern hair loss (androgenetic alopecia). It was originally designed as an oral pill to treat hypertension. It was quickly abandoned as a primary treatment for hypertension because patients didn’t tolerate the oral (pill) form very well. It is still available in oral form, but it is rarely used. One of the side effects of oral minoxidil was unwanted hair growth. This prompted a study of minoxidil in topical form, which turned out to still have the positive effect of stopping hair loss and in some cases, even regrowing hair that was lost. The topical form is better tolerated and does not have the same effects as when it was taken by mouth.

Rogaine® was the original brand name version of topical minoxidil that was FDA-approved for male pattern hair loss. After several years of Rogaine® being on the market, the FDA approved generic formulations of minoxidil. Rogaine® and generic minoxidil are both available in 2% and 5% strengths as a solution and as a foam. Minoxidil 5% has been found to be more effective in men, while the 2% and 5% are equally effective in women. Both strengths are FDA-approved for use in men and the 2% strength is also FDA-approved for use in women.

The exact mechanism of action of topical minoxidil is not completely understood. It increases the length of the growth phase of hair follicles (a process called ‘anagen’) and increases the size of hair follicles which dictates the thickness/diameter of the hair that comes out of the follicle. Minoxidil relaxes smooth muscle in blood vessel walls causing them to widen, increasing blood flow. This may be one of the ways that minoxidil works to stop or slow hair loss, and, in some cases, regrow hair.

Minoxidil tends to work best on younger men who have been experiencing progressive hair loss for fewer than 5 years. In fact, the earlier the better. However, even if started early, minoxidil is more likely to stop hair loss than to regrow hair. Hair regrowth can occur, but it is more common to stop or slow hair loss than it is to see hair regrowth. Minoxidil was studied and found to be effective at stopping or slowing down hair loss at the crown of the scalp. Interestingly, in the first few months of using minoxidil, loss of fine hairs may occur before they are replaced by thicker, more mature hairs. For some men, it can seem like it is getting a little worse before it improves.

The dose of topical minoxidil varies based on the individual. Below are general use instructions and the most common dosing.

General instructions:

1. You do not need to wash your hair before applying minoxidil; however, if you do wash your hair, your hair and scalp needs to be completely dry before applying minoxidil.

2. Apply the recommended amount to the affected areas of the scalp. Topical minoxidil is usually applied to the scalp twice daily, in the morning and at night.

3. Wash your hands after applying topical minoxidil.

4. Only use minoxidil on your scalp. Do not use on any other part of your body.

How to use topical minoxidil solution: Apply 1 mL topically to the affected area(s) of the scalp twice a day. The dose should not exceed 2 mL per day.

How to use topical minoxidil foam: Apply half a capful topically to the affected area(s) of the scalp twice per day.

Wait 4 hours after applying minoxidil to your scalp before washing your hair. It’s a good idea to develop a routine of washing and drying your hair before applying minoxidil. Wash your hands immediately after applying minoxidil to your scalp.