Orlistat is a lipase inhibitor medication approved for weight management in adults with a body mass index (BMI) of 30 or greater, or 27 or greater with obesity-related risk factors. It functions by inhibiting the absorption of dietary fats in the intestines, thereby reducing caloric intake. When used as part of a comprehensive weight management program that includes a reduced-calorie diet and exercise, orlistat has demonstrated efficacy in promoting and sustaining weight loss. This product is available in both prescription and over-the-counter formulations, depending on jurisdiction and dosage strength.

Features

• Contains orlistat as the active pharmaceutical ingredient
• Available in 60 mg (OTC) and 120 mg (prescription) strengths per capsule
• Lipase inhibitor class; acts locally in the gastrointestinal tract
• Not systemically absorbed to a significant degree
• Typically supplied in bottles of 90 or 120 capsules
• Requires concomitant reduced-calorie, low-fat diet for optimal efficacy

Benefits

• Supports clinically meaningful weight loss when combined with lifestyle modifications
• Reduces absorption of dietary fat by approximately 30%
• Helps improve obesity-related parameters such as waist circumference and blood pressure
• May aid in delaying the progression to type 2 diabetes in at-risk individuals
• Encourages adherence to a healthier, lower-fat dietary pattern
• Non-systemic mechanism minimizes risk of central nervous system side effects

Common use

Orlistat is indicated for weight management in adults with obesity or overweight with comorbidities. It is used adjunctively to a mildly hypocaloric diet—approximately 30% of calories from fat—and increased physical activity. Treatment is recommended only if a 2.5 kg weight loss has been achieved through diet alone within four weeks prior to initiation. It is not intended for use in pediatric populations or for cosmetic weight loss.

Dosage and direction

The recommended dosage is one 120 mg capsule taken three times daily with each main meal containing fat (or within one hour of completing the meal). If a meal is missed or contains no fat, the dose should be omitted. Daily fat intake should be distributed evenly over three main meals. Doses exceeding 120 mg three times daily have not been shown to provide additional benefit. Treatment beyond two years has not been extensively studied.

Precautions

Use with caution in patients with history of hyperoxaluria or calcium oxalate nephrolithiasis, as orlistat may increase urinary oxalate excretion. Monitor patients for potential decreases in fat-soluble vitamins (A, D, E, K); supplementation may be required. Not recommended for use during pregnancy or breastfeeding. Patients should be advised to follow a nutritionally balanced, reduced-calorie diet. Periodic monitoring of weight loss and BMI is advised to assess continued need.

Contraindications

Chronic malabsorption syndrome, cholestasis, known hypersensitivity to orlistat or any excipient. Concomitant use with cyclosporine is contraindicated due to altered absorption. Not recommended for use in organ transplant recipients or patients with reduced bile salt secretion.

Possible side effect

Common gastrointestinal effects include oily spotting, flatus with discharge, fecal urgency, fatty/oily stool, oily evacuation, increased defecation, and fecal incontinence. These are often dose-dependent and may decrease with continued use. Other side effects may include abdominal pain/discomfort, nausea, infectious diarrhea, headache, anxiety, fatigue, menstrual irregularities, and rare cases of hypersensitivity reactions. Severe hepatic injury has been reported rarely.

Drug interaction

May reduce absorption of fat-soluble vitamins and beta-carotene; separate vitamin supplementation by at least 2 hours. Can affect bioavailability of amiodarone, antiepileptics (e.g., valproate, lamotrigine), levothyroxine, warfarin (monitor INR closely), and oral contraceptives (recommend additional non-hormonal contraception). Avoid concomitant administration with cyclosporine.

Missed dose

If a dose is missed, resume with the next scheduled dose. Do not double the dose to make up for a missed one. Consistency with meals improves gastrointestinal tolerability and efficacy.

Overdose

Cases of overdose have reported increased severity of gastrointestinal effects. There is no specific antidote. Treatment should be symptomatic and supportive. Medical attention should be sought if severe symptoms occur.

Storage

Store at room temperature (15–30°C) in a dry place. Keep in the original container with the cap tightly closed. Protect from moisture and light. Keep out of reach of children and pets.

Disclaimer

This information is for educational purposes and does not replace professional medical advice. Always consult a healthcare provider before starting any new medication or weight management program. Individual results may vary. Use only as directed in conjunction with a reduced-calorie diet and exercise.

Reviews

Clinical studies demonstrate that orlistat, combined with lifestyle intervention, produces significantly greater weight loss than placebo over 1–2 years. In a meta-analysis of randomized trials, orlistat resulted in an average 2.9 kg greater weight loss compared to diet alone. Patient-reported outcomes often note initial gastrointestinal side effects, which frequently diminish with continued use and dietary fat moderation. Long-term users report sustained weight loss and improved metabolic markers when adherence to therapy and lifestyle recommendations is maintained.