Slimming Tea How safe & effective?

[brace]

How safe are those over the counter slimming teas like (kancura, biguerlai, kankunis etc.)? All of them claim that they are safe and made of natural ingredients but how can they assure their customers? I actually tried it but when consumed continuously I think it can cause UTI (urinary tract infection) coz after a few days I really experience pain and also faster heartbeat. Can I really associate it with the tea?

Also, I found out that after a few days of not drinking those I noticed that the stomach goes back to its actual size before.

Pls. advice. Thanks

[eyedoc]

No, not that safe, and not that effective. They mostly promote water loss (through diarrhea).