Diet pills?

These days, on Instagram and Carrot Market, there are a lot of posts about diet pills and herbal medicine. But when I look at reviews, people say that they are effective even if they don't exercise much and eat everything they want. Sometimes, I wonder if those reviews are real or if they are just part-timers. Some of the diet companies that use celebrities as models end up gaining more weight after the commercials are over, so I wonder if I can really trust them. I'm really worried about whether I should trust herbal medicine diets.