I believe that caffeine could cause hair loss. I am writing in this forum about hair loss because I saw an ad for Pura d'Or Shampoo on here and I have to tell everyone here, and especially people with hair loss issues/regrowth issues, this shampoo is the very best ever. I have bought hundreds of shampoos and this is the only one I will use now. It is pure, has organic ingredients, a scientific formulation, has argan oil, and best of all it makes my hair so incredibly shiny. I was having thyroid issues and my once very thick hair was falling out and looked wispy and was unruly and getting thinner by the day. I started with nutritional needs concurrently using this shampoo, the formulation was the one for hair loss (they have several) and I was totally amazed at how my scraggly hair appeared much better. As time has gone on, I have figured many things out, but in the meantime this shampoo nourishes the scalp, hair, and lets you feel better about yourself with better LOOKING hair while you are figuring out what is wrong nutritionally. Hope this helps someone!