Orlistat

Orlistat is available in two forms: the prescription-strength brand Xenical and the over-the-counter version Alli. Both contain the same active ingredient but differ in dosage and access.

• Xenical (prescription): 120 mg, taken three times daily with meals containing fat. Blocks approximately 30% of dietary fat absorption.
• Alli (over-the-counter): 60 mg, taken three times daily with meals containing fat. Blocks approximately 25% of dietary fat absorption.
• Timing: Both should be taken with or up to one hour after a meal that contains fat. If a meal has no fat, you can skip the dose.
• Multivitamin recommended: Orlistat can reduce absorption of fat-soluble vitamins A, D, E, and K. A daily multivitamin taken at least two hours before or after the orlistat dose is recommended.

Alli offers a lower barrier to entry — patients can purchase it without a prescription and begin at the lower dose. Xenical requires a prescription but provides more potent fat-blocking at the higher dose. For patients working with a PEAK clinician, we typically prescribe Xenical when orlistat is part of the treatment plan, as the higher dose produces more meaningful results.

Orlistat is FDA-approved for patients with a BMI of 30 or greater, or 27 or greater with weight-related health conditions. It is not the right medication for every patient, and it is not typically our first recommendation. But there are specific clinical scenarios where it fills an important role:

Patients who prefer a non-systemic medication. Because orlistat does not cross the blood-brain barrier and acts locally in the gut, it is an option for patients who want to avoid centrally acting medications.

Step therapy documentation. Some insurance plans require documented trials of lower-cost medications before approving GLP-1s. Orlistat can serve as one of these documented steps.

Patients who cannot take appetite suppressants. Patients with cardiovascular contraindications to phentermine, or who cannot tolerate stimulant-based medications, may be candidates for orlistat as an alternative approach.

Patients willing to follow a reduced-fat diet. Orlistat works best — and its side effects are most manageable — when patients commit to a lower-fat dietary pattern. Compliance with the diet is essential for both efficacy and tolerability.

Patients who want an OTC starting point. The Alli (60 mg) formulation allows patients to begin orlistat without a prescription, which may be appropriate for some patients before they establish care with a clinician.

We believe in being straightforward about every medication we prescribe. Orlistat is one tool among many, and it is not our first choice for most patients. GLP-1 medications and other options typically produce more significant results with a more favorable side effect profile for the majority of patients.

That said, orlistat fills specific niches that other medications do not. It is the only FDA-approved weight loss medication that works entirely outside the central nervous system. It is one of the most affordable options available. And it plays a meaningful role in step therapy pathways that help patients gain access to more effective medications through their insurance.

When we prescribe orlistat, it is always as part of a broader treatment plan — never as a standalone intervention. We set clear expectations about what orlistat can and cannot do, monitor your response, and adjust your plan as needed. If orlistat is a step on the path to a GLP-1, we manage that transition proactively so you are never left without a clear next step.