Well, it'll make you lose a little weight very temporarily. The main ingredient in "detox tea" is senna.Senna is a potent herbal laxative (it's what's in most commercial laxatives anyway, so if you have access to an herb shop, picking up some senna pods directly can usually save you some money). Senna is very powerful as far as laxatives go and very good for occasional constipation. The issue with this comes with the everyday consumption. It can do very serious damage to your GI Tract if consumed on a regular basis. The only "detox" you'll be getting is from your colon, and it will be highly unpleasant. It will also be very temporary, as you're just going to eat again and gain it back. So basically, yes, this is scam and potentially very dangerous. It is a sad testament to the idiocy of fat people that they think tea of any variety can make a meaningful dent in weight loss.