Orlistat: What it is and how to use it safely

Orlistat is a medicine that helps you lose weight by blocking some of the fat you eat from being absorbed. You might know it as Xenical (prescription) or Alli (over-the-counter). It’s not a miracle pill — it works best when you pair it with a lower-fat diet and regular activity.

Here’s what to expect and how to get the most from it without surprises.

How orlistat works and the usual doses

Orlistat inhibits pancreatic lipase, the enzyme that breaks down fat in your gut. If the fat isn’t broken down, it passes out of your body instead of adding calories. Typical dosing: Alli is 60 mg taken with each main meal that contains fat (up to three times a day). Xenical is 120 mg with each fat-containing meal. Take the pill during or within one hour of the meal.

If you skip a meal or the meal has no fat, skip the dose for that meal. Don’t double up to make up for a missed dose.

Common side effects and how to manage them

The most common side effects are gastrointestinal: oily spotting, gas with discharge, urgent bowel movements, and loose stools. These happen because undigested fat leaves the body. The easiest way to reduce side effects is to lower the fat in each meal—aim for about 15–30 grams of fat per meal rather than high-fat foods.

Other points: orlistat can reduce absorption of fat-soluble vitamins (A, D, E, K). Take a daily multivitamin at bedtime, at least 2 hours after taking orlistat. If you’re on important meds like levothyroxine or ciclosporin, talk to your doctor — timing or monitoring may need adjustment.

Orlistat is not for everyone. Don’t use it if you have chronic malabsorption syndrome, cholestasis, or if you’re pregnant. Tell your provider about all meds and supplements you take. If you develop severe stomach pain, persistent oily stools, or signs of liver trouble (dark urine, yellowing skin), stop and see a doctor.

What results can you expect? Most people see modest extra weight loss when they use orlistat with diet and exercise—think a few kilos over several months. It helps more if you stick to a lower-fat eating plan and keep active.

Practical tips: plan meals with lean protein, whole grains, and vegetables; avoid fried and creamy dishes; carry a small multivitamin to take at bedtime; read food labels for fat content; and set realistic goals—small steady loss is safer and easier to keep off.

If you’re curious whether orlistat fits your plan, ask your doctor or pharmacist. They’ll check your health history, other meds, and help you decide if it’s the right choice. Use it as part of a bigger plan: diet, activity, sleep, and support make the real difference.