I've never recommended anything before. But I took my beautician's advice and bought Rapid Brow as I had one very sparse brow and the other one more or less bald (hair caught fire once, burned off eyebrow too, brow never came back). She said: "Honestly, a client told me about it and said she went from thin and sparse to looking like Dennis Healey!" I thought she was exaggerating. Three weeks in and I am not kidding, they're all growing back on both brows, quite long and dark too. I actually plucked my eyebrows this morning! What's in this stuff, can could it be used for thinning hair on the head????