Xenical and alli contain the same active ingredient, orlistat. They are not interchangeable products, though: different strengths, different labeled users, different labels, and one needs a prescription while the other sits on a store shelf. Here is how the two FDA labels line up.
| Xenical | alli | |
|---|---|---|
| Active ingredient | Orlistat | Orlistat |
| Strength per capsule | 120 mg | 60 mg |
| How you get it | Prescription only | Over the counter |
| Label type | Full prescribing information for clinicians, plus patient information | Drug Facts label written for the consumer |
| Who it is labeled for | Obese patients with an initial BMI of 30 or higher, or 27 or higher with other risk factors such as high blood pressure, diabetes or abnormal blood lipids | Overweight adults 18 and older, used with a reduced-calorie, low-fat diet; a height-and-weight chart on the package helps buyers check |
| Ages | Studied in obese adolescents aged 12 to 16; not known to be safe and effective under 12 | 18 and older |
| Labeled uses | Weight loss and weight maintenance with a reduced-calorie diet; reducing the risk of weight regain after prior weight loss | Weight loss aid |
| Label daily limit | Doses above 120 mg three times a day have not been shown to add benefit | “Do not take more than 3 capsules daily” |
| Pregnancy | Contraindicated | “If pregnant or breast-feeding, do not use” |
| Kidney warning | Oxalate kidney stones and oxalate nephropathy with renal failure (Warnings and Precautions) | Ask a doctor first if you have had kidney disease or kidney stones; stop and ask a doctor for kidney injury symptoms |
| Vitamins | Multivitamin with fat-soluble vitamins, at least 2 hours before or after a dose, such as at bedtime | Multivitamin once a day, at bedtime |
Label figures above describe each product’s approved use. They are not a recommendation for anyone’s own treatment.
One drug, two strengths
Orlistat blocks enzymes in the gut that break down dietary fat, so some of the fat you eat passes out unabsorbed. The Xenical prescribing information says that at the prescription strength, orlistat inhibits dietary fat absorption by approximately 30%. The alli Drug Facts label explains the same mechanism in consumer language: orlistat “works by preventing the absorption of some of the fat you eat.”
The alli capsule holds half the orlistat of a Xenical capsule. Alli is marketed as an FDA-approved nonprescription weight loss aid; Xenical is prescribed after a clinician has assessed weight, other conditions and medicines.
Who each label is written for
Xenical’s indication uses BMI cut-offs: 30 or higher, or 27 or higher with risk factors such as hypertension, diabetes or dyslipidemia. Its label adds that the safety and efficacy have been evaluated in obese adolescents aged 12 to 16, and its patient information says it is not known whether Xenical is safe and effective in children under 12.
The alli label does not mention BMI. It is for “overweight adults, 18 years and older,” and the package includes a chart: if your weight is the same as or more than the figure listed for your height, you “may consider” starting a program with orlistat. The label lists “if you are not overweight” under Do not use. It also says diet and exercise “are the starting points for any weight loss program” and to try those first.
Different labels, different warnings
Because Xenical carries a full prescribing information document, its warnings are more detailed. It is contraindicated in pregnancy, chronic malabsorption syndrome and cholestasis. It describes rare postmarketing reports of severe liver injury, some leading to liver transplant or death, gallstones with substantial weight loss, and changes in blood sugar control in people with diabetes.
The alli label covers similar ground in shorter form. It says do not use after an organ transplant or with cyclosporine, or if you have been diagnosed with problems absorbing food. It asks you to check with a doctor first if you have had gallbladder problems, kidney disease or kidney stones, or pancreatitis, and to ask a doctor or pharmacist if you take blood thinners, amiodarone, diabetes medicine, thyroid medicine, seizure medicine or HIV medicines. It tells you to stop and ask a doctor for itching, yellow eyes or skin, dark urine or loss of appetite, which can signal liver injury.
Both labels warn about bowel changes. In Xenical’s trials, oily spotting affected 26.6% of patients in year 1 against 1.3% on placebo, and fecal urgency 22.1% against 6.7%. The alli label lists gas with oily spotting, loose stools and more frequent stools that may be hard to control. Our article on Xenical side effects explains how these usually change over time.
What results each label describes
Neither label promises dramatic loss. The alli Drug Facts say that “for every 5 pounds you lose from diet alone, orlistat can help you lose 2-3 pounds more,” and that in studies most people lost 5 to 10 pounds over 6 months. It adds that most weight loss occurs in the first 6 months.
Xenical’s label reports pooled data from five clinical trials: after 1 year, mean weight loss was 13.4 pounds with Xenical and 5.8 pounds with placebo, both alongside a diet, and the difference in mean percent weight loss between the groups was 3%. Those numbers come from different study designs and populations, so they cannot be lined up to show how much more a higher strength adds for one person.
Both labels tie bowel effects to fat intake. Xenical’s label says gastrointestinal events may increase with a diet in which more than 30% of daily calories come from fat, and the alli label says a low-fat diet lowers the chance of these changes.
The 2026 kidney warning
On June 10, 2026, the FDA announced in a Drug Safety Communication that it had approved labeling changes for alli to warn about kidney stones and kidney injury. FDA said it identified 12 cases of kidney complications linked to alli; eight people were hospitalized and five needed dialysis. FDA also said the kidney injury risk is now described consistently across labeling for all FDA-approved orlistat products, including Xenical. The current alli label tells you to stop use and ask a doctor if you develop severe pain in the back or groin, painful urination, blood in the urine, swelling of the legs or feet, or are urinating less often than normal.
Our article on orlistat and kidney injury covers what the change means and who is at higher risk.
“Can I take 2 alli instead of 1 Xenical?”
This question comes up because 2 times 60 mg equals 120 mg. The labels themselves give the answer that matters. The alli Drug Facts directions say to take 1 capsule with each meal containing fat and “do not take more than 3 capsules daily.” The Drug Facts directions describe how alli is meant to be used by someone choosing it without a clinician. Taking it in a way the label does not describe moves outside those directions, and it skips the assessment a prescriber does before Xenical: checking BMI and risk factors, kidney and liver history, and interacting medicines such as cyclosporine, levothyroxine, warfarin, amiodarone and seizure drugs.
So the honest answer is that the alli label does not support it, and any change to how orlistat is taken is a question for a prescriber or pharmacist. If alli at its labeled use is not doing enough, that is worth raising at a visit. FDA’s communication makes the same point: if you have side effects or do not respond well to alli, talk to a health care provider about other options. Our page on prescription weight-loss medicines outlines what those conversations can cover.
Both products contain orlistat and work only on fat in the meal. Both labels call for a reduced-calorie diet, a daily multivitamin because orlistat reduces absorption of some vitamins, and caution with the same groups of medicines. Both now describe the kidney injury risk, and neither should be used in pregnancy.
Vitamins and other medicines
Xenical’s label says orlistat reduces absorption of some fat-soluble vitamins and beta-carotene, and asks patients to take a multivitamin containing fat-soluble vitamins at least 2 hours before or after a dose, such as at bedtime. It sets timing rules for cyclosporine (3 hours after Xenical) and levothyroxine (at least 4 hours apart). The alli label keeps it shorter: a multivitamin once a day, at bedtime. Details for specific medicines are in our guide to Xenical, vitamins and other medicines.
Quick questions
Is alli just a weaker Xenical? It has the same active ingredient at half the strength per capsule, but it is a separate product with a separate label written for adults buying it without a prescription.
Can teenagers use alli? The alli label is for adults 18 and older. Xenical’s label includes data in obese adolescents aged 12 to 16, under a prescriber’s care.
Does the kidney warning apply to Xenical too? Yes. Xenical’s label warns about oxalate kidney stones and kidney damage, and FDA said in June 2026 that the risk is now described consistently across all FDA-approved orlistat products.
Sources
- DailyMed: Xenical (orlistat) prescribing information
- DailyMed: alli (orlistat 60 mg) Drug Facts
- FDA Drug Safety Communication, June 10, 2026: alli labeling changes on kidney stones and kidney injury
Evidence checked November 2, 2026. General information only; ask a pharmacist or prescriber before changing how you take any medicine.