At the center of this is Alpecin, a German-engineered men's shampoo. Beyond its claimed hair benefits, the caffeine in Alpecin has caught attention as a possible performance enhancer for athletes.

As a helpful guide, below are the four most common hair issues men face and what exactly to look for in a shampoo when treating ... including caffeine, biotin, antioxidants, and amino acids ...

We asked the experts. That’s where caffeine shampoo comes in. We’re sure you’ve seen the adverts on TV (and likely written them off) but, despite being around for a long time, they’re ...