Yes it can harm you, you should be very careful with some of the things you can buy in sex shops or head shops as they usually contain high concentrations of "herbal supplements" that are safe enough in low dose but definetly bad for you in large dose, i've had my good times and bad times on aphrodisiacs and ended up having to go to the ER for some fairly serious Gastro Intestinal problems from some *Namely alot of Damiana concentrate* You can end up severely damageing your Liver especially, and myself i ended up with a swollen and inflamed stomach for weeks, no ones idea of fun i assure you.