The FDA approved updated warning language for the over-the-counter weight-loss drug alli (orlistat 60 mg) on June 10, 2026, highlighting a rare but serious risk of acute kidney injury and kidney stones. The agency identified 12 cases of kidney complications linked to orlistat use between 2007 and 2023, with some patients requiring hospitalization and dialysis. If you take alli or the prescription version Xenical, understanding these warning signs could help you catch a problem early.

What Kidney Symptoms Should Alli Users Watch For?

The FDA's updated label now includes a practical symptom checklist that users should monitor while taking orlistat. These warning signs can indicate kidney injury or kidney stones and warrant immediate medical attention. The agency emphasizes that if any of these symptoms develop, users should stop taking alli and contact a healthcare provider right away.

• Back or Groin Pain: Sharp or persistent pain in the lower back or groin area may signal kidney stones or acute kidney injury.
• Painful Urination: Discomfort or burning during urination can indicate kidney or urinary tract complications.
• Blood in the Urine: Any visible blood or discoloration in urine is a red flag that requires immediate medical evaluation.
• Feet and Leg Swelling: Unexplained swelling in the lower extremities may reflect kidney dysfunction and fluid retention.
• Less Frequent Urination: A noticeable decrease in how often you urinate could signal that your kidneys are not filtering properly.

Among the 12 identified cases, the median patient age was 61 years, with slightly more women (seven) than men (five) affected. The kidney complications included eight cases of acute kidney injury, two cases of acute kidney injury combined with oxalate nephropathy (a condition where oxalate crystals damage kidney tissue), and two cases of hyperoxaluria with calcium oxalate kidney stones.

Who Should Be Extra Cautious Before Starting Alli?

The FDA's label change specifically emphasizes screening for people with a history of kidney disease or kidney stones before they start taking orlistat. If you fall into this category, talking with a healthcare provider before beginning alli is essential so you understand your individual risk and know what warning signs to monitor.

It's important to note that the FDA's analysis suggests orlistat-associated kidney injury may not be dose-dependent, meaning the risk could exist at both the 60 mg over-the-counter dose and the 120 mg prescription dose. Among the 12 cases reviewed, eight patients required hospitalization and five required dialysis, underscoring the severity of some kidney complications.

How to Safely Use Orlistat Products

• Pre-Use Screening: Before starting orlistat (whether over-the-counter alli or prescription Xenical), ask your clinician or pharmacist if you have any history of kidney disease or kidney stones.
• Symptom Awareness: Keep the FDA's symptom checklist handy and watch closely for urinary changes, flank or back pain, groin pain, and any swelling in your feet or legs.
• Immediate Action: If you develop any of the warning symptoms while taking alli, stop the medication immediately and contact your healthcare provider for guidance.
• Prescription Users: If you're taking prescription Xenical and experience symptoms, contact your prescribing clinician promptly and ask about next steps; seek urgent or emergency care if symptoms are severe.

The FDA notes that the risk information is based on postmarketing case reports, which have important limitations. The actual number of kidney complications could be higher because not all side effects get reported to the agency. Additionally, some reports lacked key clinical details such as stone composition and prior medical history, and other factors like obesity, diabetes, high blood pressure, and existing kidney disease may have contributed to the complications in some cases.

The CDC emphasizes that healthy weight loss is best achieved through a plan-based lifestyle approach that includes healthy eating patterns, regular physical activity, adequate sleep, and stress management. If you have questions about weight-loss options or medications, the CDC recommends talking with a healthcare provider to explore what's right for your individual health situation.

This FDA label update reinforces the importance of kidney history screening before starting orlistat and symptom-triggered evaluation for patients already using the medication. While the identified cases represent a small number relative to the millions of people who have used alli since its approval, the severity of some outcomes underscores why awareness and early detection matter.