That's what we're looking at today – caffeine. Not from a coffee-drinking viewpoint, but from a topically-applied, hair-growing viewpoint.
Caffeine-laden shampoos have actually been on the market for quite a while - all promising to boost hair growth, but is it just marketing hype?
Can caffeine make hair grow?
If you ask science, the answer is something like:
'documentation from laboratory tests show multiple indicators that topically applied caffeine has the ability to encourage hair growth'.
(that's science-speak for 'yeah, it looks that way')