Yes, orlistat is available over the counter in the United States under the brand name Alli at a 60 mg dose. The FDA approved it for OTC sale in 2007 for weight loss in overweight adults 18 and older. A stronger 120 mg version, sold as Xenical, still requires a prescription.
OTC vs. Prescription: What’s Different
The OTC version (Alli) contains 60 mg of orlistat per capsule, taken three times a day with meals that contain fat. The prescription version (Xenical) is exactly the same drug at double the dose, 120 mg three times a day. At the prescription strength, orlistat blocks roughly 30% of the fat you eat from being absorbed. The OTC dose blocks a smaller percentage, though the exact figure varies by person.
Both versions work the same way: orlistat disables the enzyme in your gut that breaks down dietary fat. Without that enzyme doing its full job, undigested fat passes through your system instead of being stored. This means the drug only works on the fat in the meals you take it with. If you skip a meal or eat something fat-free, you skip that dose.
Who Can Buy It
The Alli label specifies that it’s intended for overweight adults 18 and older. The packaging includes a height-and-weight chart so you can check whether you meet the minimum weight threshold for your height. The label explicitly states: “Do not use if you are not overweight.” You don’t need a prescription or a pharmacist’s approval to purchase it in the U.S., but it’s meant to be paired with a reduced-calorie, low-fat diet rather than used on its own.
Digestive Side Effects and How to Manage Them
The most common side effects are digestive: oily or fatty stools, oily spotting on underwear, gas with discharge, frequent or hard-to-control bowel movements, and stomach pain. These aren’t signs that something is going wrong. They’re a direct result of unabsorbed fat moving through your system, and they’re more intense when a meal contains too much fat.
Keeping each meal at or below 30% of calories from fat is the single most effective way to minimize these effects. On a 1,500-calorie daily diet, that works out to about 50 grams of fat spread across three meals, roughly 15 to 17 grams per meal. At 2,000 calories, the limit is about 67 grams per day. Distributing fat evenly across meals matters too. Loading most of your fat into one meal while keeping the others lean will concentrate the side effects after that heavy meal.
For most people, these symptoms are worst during the first few weeks and taper off as eating habits adjust. Many users report that the side effects actually serve as a built-in feedback loop: eat too much fat, and your body lets you know quickly.
Take a Multivitamin
Because orlistat blocks fat absorption, it also reduces absorption of fat-soluble vitamins: A, D, E, K, and beta-carotene. You should take a daily multivitamin containing all of these, but timing matters. Take it at least two hours before or two hours after your orlistat dose, or simply take it at bedtime. If you take the vitamin at the same time as the drug, orlistat will block some of that vitamin absorption too.
Drug Interactions to Watch For
Orlistat can interfere with how your body absorbs several medications because it changes fat processing in the gut. The interactions that matter most include blood thinners (warfarin), anti-seizure medications, cyclosporine (an immune-suppressing drug used after organ transplants), and thyroid hormone replacement. If you take levothyroxine for an underactive thyroid, orlistat can reduce how much of the medication your body absorbs. Spacing the two drugs at least four hours apart and monitoring thyroid levels can help, but this is something to discuss with your prescriber before starting Alli on your own.
The fact that orlistat is available without a prescription doesn’t mean it’s free of meaningful drug interactions. If you take any ongoing medications, checking for interactions before your first dose is worth the effort.
What to Realistically Expect
Orlistat is not a dramatic weight-loss drug. At the OTC dose, most users lose a few extra pounds beyond what dieting alone would achieve. The prescription dose, which blocks about 30% of dietary fat, produces modestly better results. In either case, the drug is designed as an add-on to a low-fat, reduced-calorie diet, not a replacement for one. If your diet is already low in fat, there’s less fat for orlistat to block, and the benefit shrinks accordingly.
You take one capsule with each main meal containing fat, up to three times a day. If you miss a meal or eat something with no fat, you skip that dose. There’s no benefit to taking extra capsules, as the drug works locally in your gut and only acts on the fat present in that specific meal.