Slim Fast 3-2-1 Plan, Ready To Drink Shake was effective in terms of initial weight loss. I dropped one to two pounds for week for about 10 weeks. The problem is that once I went back to eating a regular diet, I put about half of the weight back on within six months. The shakes tasted "ok", but did leave a noticeable aftertaste. I have mixed feelings about this Slim Fast product. I did see the initial results, but I do question how effective this product is for keeping the weight off. I also found that the vanilla flavor left a funny aftertaste and also left a film on my teeth. Overall, I am not super impressed with this Slim Fast product. I would consider trying a different flavor of this product to see if it did not leave an aftertaste. I would also consider using this product over a longer period of time to see if I could keep the weight off. Overall, I do not recommend this specific product but would consider using other Slim Fast products.