The more of these capsules you put on the mouse’s skin, the more hair grew back — and the strongest dose worked better than plain minoxidil.

When applied to mice, these minoxidil capsules made the hair grow back faster and thicker than regular minoxidil, by helping more hair follicles stay in the growing phase.

These capsules can hold a lot of minoxidil — half their weight — and still stay stable in solution, which is hard to do because minoxidil doesn’t dissolve well in water.