QUOTE
caffeine works by blocking the effects of a chemical known to damage hair follicles. But drinking plenty of coffee may not be the best answer. Scientists estimate up to 60 cups a day would be needed for significant amounts to reach follicles in the scalp. Instead, German cosmetics firm Alpecin has developed a caffeine-rich solution that can be rubbed on the scalp. [...]Dr Tobias Fischer, who carried out the latest research at the University of Jena in Germany.
Oh and for you Daily Mail haters, here's the abstract from the International Journal of Dermatology