The drug is called alli, it’s the low-dose version of the prescription drug Xenical, and as I understand it, it works by basically passing a portion of consumed fat through the body undigested. It sounds like the general effect of this is “loose stools” but if you eat a fat-laden meal, look out.

alli/GSK calls this a “treatment effect” rather than a side effect, because it’s what the drug is designed to do, the central purpose. They’ve done a good job of setting expectations, though, which I think is crucial to their success. With their blog, they’re essentially beating critics to the punch by pointing out potential issues upfront, which is both smart and surprisingly transparent for a big pharma company.

Part of the desired outcome is that alli users would start eating more healthfully as well as taking the drug, and it seems like you’d want to do that just to keep the “treatment effects” under control. Still, I think I’m happy enough with my current progress to keep counting the calories in the pizza I’m eating right now rather than choose between avoiding the pizza or dashing for the bathroom.

Despite its downside, it seems like this could be one more useful weapon in the dieter’s arsenal. Are any of you planning on trying it? If so, what kind of weight loss results are you expecting?