I think it would be fine to try these, but if there is too much caffeine and you become irritable, then cut back. If you already drink coffee, I would think it would be too much.
Another one that helps control blood sugar and help your insulin is cinnamon. I do drink coffee, so I have been adding it to my coffee. This is pure cinnamon without sugar.
The Only Way to loose weight is via a lifestyle change and a steady dose Of exorcise. Don't take any short cuts. You will will end up gaining it back and hurting yourself.