Xenical (Xenical)
Weight Loss Treatment
Orlistat is used with an individualized low-calorie, low-fat diet and exercise program to help people lose weight. It works by preventing some of the fat in foods eaten from being absorbed in the intestines.
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Xenical Product Information
Orlistat is used with an individualized low-calorie, low-fat diet and exercise program to help people lose weight. It works by preventing some of the fat in foods eaten from being absorbed in the intestines.
Orlistat is in a class of medications called lipase inhibitors. It works by preventing some of the fat in foods eaten from being absorbed in the intestines. This unabsorbed fat is then removed from the body in the stool.
Orlistat is in a class of medications called lipase inhibitors. It works by preventing some of the fat in foods eaten from being absorbed in the intestines. This unabsorbed fat is then removed from the body in the stool.
Orlistat comes as a capsule and a nonprescription capsule to take by mouth. It is usually taken three times a day with each main meal that contains fat. Take orlistat during a meal or up to 1 hour after a meal. If a meal is missed or does not have fat, you may skip your dose.
Not explicitly stated, but it works by preventing fat absorption with each meal.
Not explicitly stated, but it works with each meal.
Xenical Quick View
| Active Ingredient | Orlistat |
|---|---|
| Manufacturer | H2 Pharma (for Xenical 120mg), Roche (original manufacturer of Xenical) |
| Type | Lipase inhibitor |
| Onset | Not explicitly stated, but it works by preventing fat absorption with each meal. |
| Duration | Not explicitly stated, but it works with each meal. |
| Food Interaction | Orlistat works by preventing fat absorption from food. High-fat meals increase side effects. Should take a daily multivitamin with fat-soluble vitamins (A, D, E, K) and beta-carotene, 2 hours before or after Orlistat, or at bedtime. |
| Alcohol | Not explicitly mentioned in this source. |
| Prescription | Available as both prescription (Xenical 120mg) and nonprescription (Alli 60mg). |
Xenical Side Effects
Common Side Effects
- oily spotting on underwear or on clothing
- gas with oily spotting
- urgent need to have a bowel movement
- loose stools
- oily or fatty stools
- increased number of bowel movements
- difficulty controlling bowel movements
- pain or discomfort in the rectum (bottom)
- stomach pain
- irregular menstrual periods
- headache
- anxiety
- back pain
- difficulty with moving
- gas with leaky bowel movements
- inability to hold bowel movement
- increases in bowel movements
- loss of bowel control
- oily bowel movements
- oily spotting of underclothes
- stomach pain or discomfort
Uncommon Side Effects
- chest tightness
- tooth or gum problems
- trouble breathing
- itching of the vagina or genital area
- menstrual changes
- pain during sexual intercourse
- rectal pain or discomfort
- thick, white vaginal discharge with no odor or with a mild odor
Rare Side Effects
- bladder pain
- body aches
- chills
- cough
- diarrhea
- difficulty with breathing
- ear congestion
- fever
- general feeling of discomfort or illness
- headache
- loss of appetite
- loss of voice
- lower back or side pain
- muscle aches and pains
- nasal congestion
- nausea
- runny nose
- shivering
- sneezing
- sore throat
- sweating
- trouble sleeping
- unusual tiredness or weakness
- vomiting
- bloody or cloudy urine
- change in hearing
- contagious diarrhea
- dark urine
- difficult or painful urination
- earache
- fast heartbeat
- frequent urge to urinate
- general tiredness and weakness
- hives
- hoarseness
- irritation
- itching
- joint pain, stiffness, or swelling
- large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
- light-colored stools
- noisy breathing
- rash
- redness of the skin
- skin blisters
- swelling of the eyelids, face, lips, hands, or feet
- trouble swallowing
- upper right abdominal or stomach pain
- yellow eyes and skin
Important Warning: Some people who took orlistat developed severe liver damage. There is not enough information to tell whether the liver damage was caused by orlistat. Talk to your doctor about the risks of taking orlistat.
More Information About Xenical
Storage
Keep in original container, tightly closed, out of reach of children. Store at room temperature, away from excess heat, moisture, and light.
Contraindications
Not explicitly listed as a single section, but from MedlinePlus: organ transplant, cholestasis, malabsorption syndrome, pregnancy, breast-feeding. From Mayo Clinic: Not to be used if you have chronic malabsorption syndrome or cholestasis.
Drug Interactions
From MedlinePlus: cyclosporine (take 3 hours after orlistat), levothyroxine (take at least 4 hours apart from orlistat), fat-soluble vitamins and beta-carotene (take at least 2 hours before or 2 hours after orlistat, or at bedtime). From Mayo Clinic: warfarin, other weight-loss products, amiodarone, antidiabetic agents, fat-soluble vitamins, cyclosporine, levothyroxine.
Xenical FAQs
Orlistat is a lipase inhibitor that works by preventing some of the fat from the food you eat from being absorbed in your intestines. This unabsorbed fat is then passed out of your body in your stool.
You should follow a reduced-calorie, low-fat diet. It's important to evenly divide your daily intake of fat, carbohydrates, and protein over three main meals. Avoid meals with more than 30% of calories from fat to minimize side effects.
Common side effects include changes in bowel habits such as oily spotting, gas with oily discharge, urgent need for bowel movements, loose or oily stools, and increased frequency of bowel movements. These are often more pronounced with high-fat meals.
Orlistat is available in two strengths: a 120mg prescription strength (Xenical) and a 60mg over-the-counter strength (Alli).
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Content last updated: 14 Apr 2026
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