Alli (Orlistat)

Description

Alli is a weight-loss aid for adults aged 18 and older who are overweight. It contains orlistat and should be used with a lower-calorie, low-fat diet and regular physical activity. Unlike many diet products, Alli works in the digestive system rather than affecting the brain or appetite. It prevents the body from absorbing some of the fat eaten at meals, which then passes through the stool. The drug label states that those who take Alli may lose an extra 2 to 3 pounds for every 5 pounds lost through diet alone, with many study participants losing 5 to 10 pounds over six months.

Directions

Take one capsule with each main meal that contains fat, up to three capsules a day. Skip the dose if you skip the meal or if the meal has no fat. Eating lower-fat meals may improve weight-loss results and reduce stomach and bowel side effects.

Start with a healthy eating and exercise plan before using Alli, and ask a healthcare provider before starting a new exercise routine. Take a daily multivitamin at bedtime because Alli can reduce your body's absorption of certain vitamins. Taking it at night keeps it separate from your Alli doses.

Most weight loss happens in the first six months. If you stop taking Alli, continue your diet and activity plan. You may restart it if weight returns. Store it at 68°F to 77°F (20°C to 25°C), away from light, moisture, and heat above 86°F (30°C).

Ingredients

The active ingredient in Alli is orlistat. Inactive ingredients may include edible ink, FDandC Blue No. 2, gelatin, iron oxide, microcrystalline cellulose, povidone, sodium lauryl sulfate, sodium starch glycolate, talc, and titanium dioxide.

Cautions

• Before using this medication, you may want to consult a healthcare provider about the following:
  • Any existing health conditions
  • Any allergies
  • A list of all medications currently being taken
• Check with a healthcare provider first if there is any history of gallbladder trouble, kidney disease or kidney stones, or pancreatitis.
• A number of prescription medications interact with orlistat and may not work as well or need their doses adjusted, including blood thinners, amiodarone, diabetes medications, thyroid replacement, seizure medications, and HIV antiretrovirals.
• A daily multivitamin at bedtime is part of using Alli properly, as the drug can reduce the absorption of fat-soluble vitamins.
• Liver injury has been reported on rare occasions. Itching, yellowing of the eyes or skin, urine that has darkened, or a lost appetite are reasons to stop and see a healthcare provider.
• Kidney injury has also occurred in rare cases. Stop and seek advice for severe back or groin pain, pain on urinating, blood in the urine, swollen legs or feet, or passing less urine than usual.
• Anyone taking seizure medication who finds their seizures becoming more frequent or more severe should stop Alli and speak to a healthcare provider.
• Keep the bottle out of reach of children.

Contraindications

Avoid taking or using this medication if any of the following apply:

• A previous organ transplant, since orlistat may interfere with the medications that keep the body from rejecting a transplanted organ
• Current treatment with cyclosporine
• An allergy to any ingredient in orlistat capsules
• A diagnosis of malabsorption, meaning the gut already has trouble taking up food
• Not being overweight
• Pregnancy or breastfeeding

Side Effects

As unabsorbed fat has to leave the body somehow, most effects of Alli involve the bowels. Reported effects include:

• Gas alongside oily spotting
• Loose stools
• More frequent bowel movements that may be urgent or hard to control
• Oily or fatty stools
• Stomach discomfort

These bowel changes tend to be at their most noticeable in the early weeks and settle as meals get leaner. Stop Alli and speak to a doctor about itching, yellow eyes or skin, dark urine, appetite loss, severe back or groin pain, painful or bloody urination, swollen legs or feet, or reduced urine output. Seek emergency care for a rash, itching, swelling, severe dizziness, or difficulty breathing, which may indicate a serious allergic reaction.

References

Alli Prescribing Information. Warren, NJ: Haleon US Holdings LLC; 2026.

Alli Drug Label Information. Warren, NJ: Haleon US Holdings LLC; 2026.

About Dr. Gerardo Sison (Page Author)

An honors graduate of the University of Florida, Dr. Sison started his pharmacy career in a community setting, extending his services to hospitals and clinics over time. He has also worked in medication therapy management, advising patients on proper medication use for their chronic health conditions. Read More....