There are basically two types of weight loss drug:  over the counter (OTC) and prescription-only.  Alli is the OTC variety and is often seen as a great way of losing weight for those who aren't eligible for prescription drugs.

Alli is simply a weaker version of the prescription-only drug Xenical.  And interestingly, it's the only OTC drug to have been approved by the FDA.  So if you're over 18 years old and only a bit overweight then you might find it works great for you.  However there are some issues that you need to be aware of.

How does it work?

It works by interfering with the way your body digests and absorbs fat from your diet.  If you absorb less fat then you'll lose weight.  However one of the things that's important when taking Alli is that you go on low fat and low calories diet.  Why?  Well, if you don't then you'll end up with some of the side-effects, also known as “treatment effects.”

What are the side-effects?

The side-effects are very off-putting for many people and is the main reason why people often reject it as a weight loss drug.  Loose stools, greasy farts and uncontrollable bowel movements are amongst the problems.  There's also some problems with liver damage.

You see, when your body is prevented from digesting fats, the fat just passes out of your body.  So if you look into the toilet bowl and see an oily substance floating about then that's your undigested fat.  As a result, you're urged to reduce the amount of fat you eat.

There are a couple of ways of thinking about Alli.  Either you could consider it a waste of money because if you're forced to go on a low fat diet you'd lose weight anyway.  Alternatively you could see the “treatment effects” as being a warning sign that you're eating too much fat - the proverbial canary down the mine.

Can anyone take Alli?

No, you should avoid Alli if you fall into any of the following categories:-

• You're not overweight
• You take cyclosporine
• You have food absorption problems
• You've had surgery

If you're currently on meds such as those for thyroid disease, thinning your blood or diabetes then you should always talk to a doctor before taking Alli or any other kind of prescription of OTC weight loss pill for that matter.

Is the weight loss permanent?

No, any kind of weight loss plan is only temporary.  This is regardless of whether you lose weight through dieting, exercise or liposuction.  If you go back to your old habits the weight will just creep back.  This means that if you buy Alli then it should be a long-term commitment.