Made famous by old adverts, minoxidil was a blood pressure medication with side effects. The side effect that interested them the most was random hair growth.
After random hair growth was noticed, the original creators of minoxidil decided to begin marketing it as a hair growth medication.
Here's minoxidil explained shortly:
Minoxidil is a vasodilator that causes nutrient supply to be increased. As a result, when minoxidil is applied to the scalp, it causes random hair growth.
Here's the problem with using minoxidil for hair loss.
Minoxidil doesn't stop hair loss. It causes random hair growth. Therefore, for a short period of time, it masks the amount of hair being lost. Eventually, the amount of hair loss caused by male pattern baldness exceeds the amount of hair minoxidil can coerce into growing—and the effects wear off.
Treating hair loss is simple: block DHT, reduce inflammation, stimulate hair growth. Don't half ass it.