Orlistat (Xenical): the non-GLP-1 option, and how it actually works

Orlistat (Xenical): the non-GLP-1 option, and how it actually works

Orlistat does not touch your appetite. It works in your gut, blocking some of the fat you eat from being absorbed. It is gentler in effect, and it suits people the injections do not.

LM
LoveMyLife Weight Management team
14 June 2026 6 min read

Orlistat, sold as Xenical, works in a completely different way from the GLP-1 injections. It is not a GLP-1 at all. It does not act on your appetite or your brain. Instead it blocks an enzyme in your gut so that about a third of the fat in your food passes through undigested rather than being absorbed. Fewer calories in, without changing how hungry you feel.

How well it works

Orlistat is the gentlest of the weight medications, and its results are gentler too. Most people lose around 3 to 5% of their body weight over a year, on top of what diet and activity achieve. That is less than the GLP-1s deliver, and we will be straight with you about it. Orlistat works best as part of a genuine effort to eat well, not as a substitute for one.

Who it suits

It comes into its own for people the injectables do not suit: if a GLP-1 is not safe for you, if you cannot tolerate one, or if you simply do not want an injection or a drug that works on your appetite. It is a capsule you take with meals, nothing more complicated than that.

How you take it

You take one capsule with each main meal that contains fat, up to three times a day. If you skip a meal, or eat one with no fat in it, you skip the capsule. Because it reduces how well your body absorbs fat-soluble vitamins, we suggest a daily multivitamin taken at bedtime, away from your doses.

The honest bit: side effects

This is worth knowing before you start. Orlistat's side effects come straight from how it works. The fat it blocks has to go somewhere, so a high-fat meal can mean loose, oily stools and urgent trips to the loo. It eases as you eat less fat, which is rather the point: the medication nudges you toward a lower-fat diet by making the alternative uncomfortable. Keep your meals sensible and most people get on with it fine.

Who should not take it

We will not prescribe Orlistat in pregnancy or breastfeeding, or where you have certain gut, gallbladder, or absorption conditions. It can also change how some other medicines work, so the assessment goes through what you already take before anything is prescribed.

Starting Orlistat

If you have used Orlistat before and know it suits you, you can order it from our pharmacy and we will dispense it after a clinical check. If you are new to it, or not sure it is the right fit, begin with the assessment instead and a doctor will help you decide.

SR
Clinically reviewed
Dr Seth Rankin
MBChB MRCGP, Founder, LoveMyLife

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Ready to start?

If this has helped you think it through, the next step is a short assessment with one of our weight-management doctors. It takes about ten minutes and tells you whether medication is right for you. Begin your assessment.