Orlos vs Orlistat: What’s the Difference Between 60mg and 120mg?

Orlos is a branded version of orlistat 60mg, meaning it contains the same active ingredient as other orlistat medicines. In the UK, pharmacies can sell Orlos 60mg over the counter after a suitability assessment, while the higher-strength orlistat 120mg requires a prescription. The main difference is the dose, not the medicine itself.

If you're considering weight loss medication in the UK, comparing Orlos vs. orlistat can be confusing. This guide explains whether they're the same medicine, how they differ in strength and prescription requirements, and which option may suit your needs.

Key Takeaways: Orlos vs Orlistat

• Orlos is a branded version of orlistat 60mg, not a different medicine.
• The main comparison is 60mg versus 120mg. Orlistat 60mg is available over the counter at registered pharmacies in the UK, while the higher dose is prescription-only.
• Orlos and Alli contain the same active ingredient, orlistat 60mg.
• Orlistat minimizes fat absorption. Unlike GLP-1 weight-loss injections, it doesn't directly suppress appetite.
• Side effects related to the digestive system are common, especially after high-fat meals.
• Ask a pharmacist or prescriber to assess your needs and recommend a treatment that suits you. Clinical guidance suggests reassessing weight loss treatment after three months.

Orlos Is Orlistat 60mg, Not a Different Medicine

Orlos is a generic nonprescription weight-loss medication that contains 60mg of the active ingredient orlistat. It's a branded version of orlistat 60mg supplied in the UK by Crescent Pharma.

Another branded version of orlistat 60mg is Alli. Haleon UK Trading Limited (2023) classifies Alli as a pharmacy medicine and is authorised to market it in the UK as an over-the-counter weight-loss medication.

At the higher strength, Xenical contains orlistat 120mg. Generic 120mg capsules contain the same active ingredient at the same dose as Xenical orlistat.

The NHS (2026) states that Alli, Orlos and Xenical are brands of orlistat. The main difference is their availability. The 60mg formulation is available over the counter after an appropriate assessment, while Xenical 120mg is only available by prescription. The main differences in licensing, access, and dosing come from the strength, not the brand name.

How Orlistat Works to Reduce Fat Absorption

Orlistat is a lipase inhibitor that works inside the digestive system. It inhibits gastric lipase and pancreatic lipase, enzymes responsible for converting dietary fat into an absorbable form in the small intestine. Orlistat prevents these enzymes from working, and unabsorbed fat passes out of the body in the stool.

How much is blocked depends on the dose. According to Haleon UK Trading Limited (2023), orlistat 60mg prevents the absorption of around 25% of dietary fat if you’re taking it three times a day. Orlistat 120mg (prescription) blocks the absorption of about a third of the dietary fat (NHS, 2026).

Unlike GLP-1 medications, orlistat doesn't directly act on appetite signals in the brain. It also doesn't prevent the absorption of carbohydrates or sugar. This explains why it's recommended to take orlistat alongside a calorie-controlled diet.

Orlistat reduces the absorption of some dietary fat, but if you eat more calories than your body needs, you won't lose weight. The two strengths work in exactly the same way but differ in their effects on fat absorption.

Orlistat 60mg vs 120mg: What Changes with the Higher Dose?

The main differences between Orlistat 60mg and Orlistat 120mg are strength, eligibility, and prescription requirements.

Sources: Haleon UK Trading Limited (2023); NHS (2026).

Prescription Requirements and Treatment Duration

Orlistat 60mg is sold over-the-counter without a prescription, but a pharmacist must decide if it's suitable. On the other hand, Orlistat 120mg is a prescription-only medication. It's licensed for adults with a BMI of 30 or higher, or 28 or higher if they have health conditions such as type 2 diabetes and/or high blood pressure.

Both strengths need a controlled-calorie, low-fat diet and regular physical activity. Their product information recommends taking orlistat before, during, or up to one hour after each main meal containing fat. If you miss a meal or have a fat-free meal, skip the dose.

There are also variations in the frequency of treatment reviews. Under official UK/European product licensing (SmPC), over-the-counter orlistat 60mg is licensed for a maximum continuous treatment period of 6 months. If you don't lose weight after 12 weeks, consult a doctor or pharmacist.

Prescribing information for orlistat 120mg recommends discontinuing the medication after 12 weeks if the patient hasn't lost at least 5% of their initial body weight (Neon Healthcare Ltd, 2023; Haleon UK Trading Limited, 2023). Check with a pharmacist or prescriber how you're doing after 12 weeks, and they'll decide if you should continue with treatment.

Check out our orlistat (generic Xenical) page for more information on prescription, treatment details, side effects, and the current price.

Orlos vs Alli: Do Both Orlistat 60mg Brands Work the Same Way?

Orlos and Alli have the same active ingredient and strength. Both are over-the-counter orlistat (60 mg) capsules recommended for weight loss, alongside a lower-fat, reduced-calorie diet. They work through the same mechanism in the digestive tract, so there's no evidence that one brand delivers better weight loss than the other. The main differences are the manufacturers, packaging, prices, and potentially the inactive ingredients used in the capsules.

These details are particularly important if you have a known allergy or sensitivity to an excipient. When choosing a branded version, compare the current price per capsule, availability, and ingredients. Also ask a pharmacist to confirm if either formulation is appropriate based on your medical history and current medications.

What Side Effects Can Orlistat 60mg and 120mg Cause?

Orlistat 120mg and 60mg have similar side effects on the gastrointestinal system, as they both prevent the absorption of some of the dietary fat from the food. The typical side effects include oily or fatty stools, diarrhoea, abdominal pain, fatty spotting with flatus, and urgent or more frequent bowel movements (NHS, 2026).

These symptoms occur because unabsorbed fat passes through the bowel. Many people experience them early in treatment and after eating high-fat meals.

The higher dose blocks more fat, which may increase gastrointestinal discomfort. A 6-month dose-ranging study by Van Gaal et al. (1998) directly compared multiple doses of orlistat (including 60mg and 120mg) alongside placebo. The study found that gastrointestinal side effects were common across treatment groups because of its mechanism of action.

How Can You Reduce Digestive Side Effects?

Both strengths require a well-balanced lower-fat diet. The product information recommends that fat should be only 30% of your total daily calorie intake, distributed across main meals (Neon Healthcare Ltd, 2023; Haleon UK Trading Limited, 2023). Monitoring your fat intake can help you identify meals that trigger digestive problems. Don't eat all of the fat for the day in one meal.

Orlistat may also interfere with the absorption of fat-soluble vitamins A, D, E, and K. The 60mg product information advises taking a multivitamin at bedtime. If you're on the prescription strength, your prescriber should recommend dietary supplements.

Some people also experience rare but serious side effects, such as problems with the liver. If you have any concerning symptoms, seek medical advice. Read our comprehensive guide on orlistat side effects to learn more about managing its symptoms and what to look for as warning signs.

What Do Clinical Trials Show About Orlistat Weight Loss?

Clinical trials show that orlistat can help individuals lose more weight than diet and lifestyle changes alone. But the additional weight loss is generally modest, and outcomes vary between individuals.

Orlistat 60mg Clinical Trials

The European Medicines Agency (2012) reviewed studies on Alli 60mg in adults with a BMI of at least 28. Across two studies, participants taking orlistat 60mg lost an average of 4.8kg after one year, compared with 2.3kg among those taking a placebo. Both groups also followed a controlled-calorie diet.

In those studies, the extra average weight loss was about 2.5kg. A separate study of adults with a BMI range of 25-28 found no clinically significant weight-loss benefit.

Orlistat 120mg Clinical Trials

In a study called XENDOS, 3,305 adults with obesity underwent a four-year prescription-strength orlistat treatment and placebo group, along with lifestyle modifications. After 4 years, those who took orlistat 120mg lost 5.8kg on average, whereas the placebo group lost 3.0kg on average. The research also found a 37.3% relative risk reduction based on its time-to-event analysis for new type 2 diabetes cases. The cumulative incidence was 6.2% with orlistat and 9.0% with placebo (Torgerson et al., 2004).

These results validate the efficacy of orlistat, but don’t indicate the amount of weight each person can expect to lose. The studies also differ in follow-up time and population. Therefore, the results can't be used to directly compare the two strengths.

Who Can Take Orlistat for Weight Loss in the UK?

The National Institute for Health and Care Excellence (NICE, 2026) recommends orlistat for adults who meet relevant weight-management criteria. Orlistat 120mg is prescribed to adults with a BMI of 30 or higher, or a BMI of 28 or higher with weight-related risk factors.

The 60mg pharmacy strength is licensed for adults (aged 18 years and over) who have a BMI of 28 or higher. However, meeting the BMI criteria doesn't automatically mean orlistat is suitable for you.

Orlistat isn't suitable for people with long-term malabsorption syndrome or cholestasis, and pregnant or breastfeeding women. Orlistat may also interact with other medications, such as ciclosporin and anticoagulants. There are some restrictions depending on the formulation, so the pharmacist or prescriber should check your medical history and current medications before you begin treatment.

NICE (2026) also recommends considering using weight loss medications in combination with diet, exercise and behavioural changes. A pharmacist or prescriber can check if you're suitable for treatment, discuss realistic weight-loss goals, and schedule your next review to see if it's still appropriate.

How Does Orlistat Compare With Other Weight Loss Treatments?

Unlike injectable weight-loss medications (like semaglutide and tirzepatide), orlistat targets the digestive system. These injections alter the appetite and eating habits, while orlistat acts by blocking the absorption of fat from the digestive system.

Some injectable treatment clinical trials have reported higher mean weight loss than orlistat trials, but the results may not be comparable because of differences in study design. Prescription-only orlistat 120mg is a good alternative for people who can’t or don’t want to use weight loss injections such as Mounjaro, Wegovy, or Saxenda. At 60mg, it's also available over the counter without a prescription from the pharmacy.

But it’s not just about convenience. Medical history, possible side effects, benefits, and eligibility are all important. If you want to get a better understanding of the options, check out our weight loss pills page for more information on what the different treatments are and who's eligible for them.

Frequently Asked Questions

How Long Does Orlos Take to Start Working?

Orlos starts blocking fat absorption with your first dose, and changes in stool fat can appear within 24 to 48 hours. However, noticeable weight loss usually takes several weeks. Your results depend on your diet, exercise, and consistency with treatment (Haleon UK Trading Limited, 2023).

Can I Take Two Orlos 60mg Capsules Instead of One Orlistat 120mg Capsule?

No, unless your prescriber specifically advises it. Although two 60mg capsules contain the same amount of orlistat as one 120mg capsule, don't increase your dose on your own. The maximum over-the-counter dose is three 60mg capsules daily, taken separately immediately before, during, or after main meals (Haleon UK Trading Limited, 2023).

Can You Drink Alcohol While Taking Orlistat?

Generally, it’s fine to drink alcohol in moderation while taking orlistat. Studies have found no direct interaction between the two. But alcohol has calories that orlistat can't block, and too much intake can hinder your weight loss journey, especially if you're on a low-calorie diet.

Does Orlos Affect the Contraceptive Pill?

Orlos doesn't directly reduce the effectiveness of the contraceptive pill. Severe diarrhoea can prevent the absorption of the pills, though. Use additional contraception and follow the guidelines for the pill if diarrhoea is very severe or lasts for a long time. If you're not sure how long you need extra protection, ask a pharmacist (NHS, 2026).

Can People With Type 2 Diabetes Take Orlistat?

Some people with type 2 diabetes may take orlistat, but should check with a doctor before beginning the treatment. Weight loss may help manage blood glucose levels, and you may need to adjust diabetes medications. Your doctor will know how to monitor it and if the dose needs to be adjusted (Haleon UK Trading Limited, 2023).

Will I Regain Weight After Stopping Orlos?

Weight gain is possible when you stop taking Orlos, but not necessarily. The action of orlistat on fat absorption typically stops 48 to 72 hours after taking the last dose. To maintain your weight-loss results, eat a balanced diet, monitor your daily calorie intake, and exercise regularly.

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Final Thoughts

Orlos and orlistat aren't different medicines. Orlistat comes in two forms (60mg and 120mg), with the higher strength (120mg) requiring a prescription from a qualified prescriber, while the lower dose is available over the counter after a consultation. Both reduce fat absorption from the diet, but the higher strength is more effective. Don’t use either as a substitute for a balanced, calorie-controlled diet or regular exercise.

If you're considering this medication, talk to a pharmacist or prescriber before you buy orlistat. They will consider your medical history and suggest the right dose to help you reach your weight-loss goals.

References

• European Medicines Agency. (2012). Alli (orlistat): EPAR summary for the public.
• Haleon UK Trading Limited. (2023). alli 60 mg hard capsules: Summary of product characteristics. Electronic Medicines Compendium.
• National Health Service. (2026, May 6). Orlistat. NHS Medicines A to Z.
• National Institute for Health and Care Excellence. (2025). A guide for prescribing medicines to manage overweight and obesity [Implementation support resource].
• National Institute for Health and Care Excellence. (2026). Overweight and obesity management (NICE Guideline NG246).
• Neon Healthcare Ltd (2023). Xenical 120 mg hard capsules: Summary of product characteristics. Electronic Medicines Compendium.
• NHS Specialist Pharmacy Service. (n.d.). Orlos 60mg capsules (Crescent Pharma Ltd) [Medicines record].
• Torgerson, J. S., Hauptman, J., Boldrin, M. N., & Sjöström, L. (2004). XENical in the prevention of diabetes in obese subjects (XENDOS) study: A randomized study of orlistat as an adjunct to lifestyle changes for the prevention of type 2 diabetes in obese patients. Diabetes Care, 27(1), 155–161.