Orlistat is the stuff that allows the fat you eat to pass straight through your system, isn't it? I can't remember its common name.
I was prescribed it in the 1990s, when it first came out. I can't remember whether it helped me lose weight or not, which would suggest it didn't suit me. The one thing I do remember, is that if you eat anything fatty at all (1 piece of quiche was my problem) you get horrible, yellow, oily diarrhoea. If you want to stick with it, you really have to watch your fat intake like a hawk, or suffer the consequences. I gave up on it.
Later on I tried Atkins - exactly the reverse, low carbs, high protein and fat - and discovered that it suited me much better. I'm back on it now, and it certainly keeps my BGs both low and stable. My diet is a sticky thread on the Low-carb Diet Forum - Viv's Modified Atkins Diet.
Viv 8)