I tried these several months ago; I took them for about two weeks before I had to stop because they caused my heart rate to be elevated. I looked into it and found several others who reported similar things. I think it has to do with the form of horsetail extract they use. My heart rate returned to normal after I stopped taking them.
I will say that as far as my hair, I had 3/4 of a inch after two weeks (I normally get .5 -.75 inches a month) and even though I ended up discontinuing my use at the end of that period I still got a full inch that month.
I will obviously never take them again but I I do think they are worth trying, just be aware of how your body responds. My mom took the remainder of my mine and didn't have any problems (she didn't have the same results as far as hair growth but she wasn't very consistant in taking them).
3c/b, medium density, medium texture, low-normal porosity.
Cleanse: DevaCurl No-Poo
Hydrate: Giovani Direct Leave-In
Style: Shea Moisture Curling Gel Soufflé
Refresh: an oil blend (no one in particular)
Wash and go 2x per week, henna every 3 weeks.
CG since 3/31/12
Hennahead since 7/2/13
Patiently growing my (unstretched) curls to APL