Hey Natalie!
I'm a pharmacist and I would strongly advise against these pills especially if you are following the slumming world plan.
These tablets work on the principle of binding the fat in the food you eat this is then excreted in the form of oily diarrhoea, you need to ensure that each Neal you eat is limited to a certain amount of fat if you don't the side effects can be very bad: oily stools, flatulence, tummy cramps to name a few! The over the counter tablets are actually half the strength of the ones you get on a prescription and so how much weight you actually loose will vary.