I'm on week 2, and I've lost 5 pounds, which I'm pleased about. Saxenda binds to the hormone Gherlin (I think that's the name). Less of this hormone available means you get full quicker and stay fuller for longer. One of the side effects is it makes you feel a little seedy, a bit like mild morning sickness.
So the combo of feeling full, staying full and slight nausea makes it much, much easier to stick to low calories (or low fat) diet. I struggle to eat half the amount I normally do, and like others leave crisps and Chocolate in the cupboard uneaten.
I know some (thin) people who just aren't that interested in eating and I sort of feel that way for the first time in my life!
Cost wise, on the lowest dose (0.6mg) 1 pen lasts 17 days. You are supposed to go up to 3mg do one pen (50 odd quid) will last a week.
I agree, it's expensive, but I've came to the conclusion that if I can successfully lose weight, I don't care how much it costs - I go and get my nails and hair done to make me feel and look better but no expensive clothes or make up covers up the fact I need to lose two stone (well, 3 probably).
I've just bought 5 pens to last a month, and plan on sticking to a calorie deficit diet and hope to lose maybe two stone by Christmas.