Xenical
In brief
- Xenical (orlistat) 120 mg is a prescription-only medicine (POM) in the UK; the 60 mg alli brand is a pharmacy medicine (P).
- Xenical is used for weight loss and weight maintenance in adults with obesity or overweight, alongside a reduced-calorie, low-fat diet. It works as a gastrointestinal lipase inhibitor, reducing the absorption of dietary fat from the intestine.
- The usual adult dose is 120 mg three times daily with each main meal containing fat, or up to 1 hour after the meal. Doses above 120 mg three times daily do not improve efficacy.
- It is taken by mouth as a capsule.
- Xenical starts working as soon as it is taken with a meal, with the fat-blocking effect beginning during digestion of that meal.
- Its effect lasts for the duration of the meal and the digestion period afterwards; it is taken with each fat-containing main meal, up to three times daily.
- Alcohol does not have a direct interaction with Xenical, but heavy drinking may make weight loss harder and can worsen gastrointestinal side effects if your diet is high in fat.
- The most common side effects are oily or fatty stools, oily spotting, increased defecation, faecal urgency, flatulence with discharge, and abdominal cramping.
- Would you like to try Xenical without a prescription?
Basic Xenical information
- INN (international nonproprietary name): Orlistat
- Brand names available in the United Kingdom: Xenical (120 mg); alli (60 mg)
- ATC code: A08AB01
- Forms and dosages: Capsules 120 mg (Xenical); capsules 60 mg (alli)
- Manufacturers in the United Kingdom: Roche (Xenical); generic orlistat suppliers
- Registration status in the United Kingdom: Xenical 120 mg is a prescription-only medicine (POM); alli 60 mg is a pharmacy medicine (P)
- OTC / Rx classification: Xenical 120 mg: prescription-only medicine (POM); alli 60 mg: pharmacy medicine (P)
Xenical at a glance
What Xenical is
Xenical is the branded version of orlistat, an INN listed as Orlistat with ATC code A08AB01.
It is a prescription weight-loss medicine that is usually discussed alongside reduced-calorie eating plans, not as a quick fix.
Xenical, orlistat and alli explained
- Xenical
- The main prescription brand of orlistat, usually supplied as Xenical 120 mg capsules.
- Orlistat
- The generic name for the medicine, used in both branded and generic products.
- Alli
- The lower-strength 60 mg version, a pharmacy medicine (P) supplied under pharmacist supervision.
How Xenical works in plain English
Fat absorption and lipase inhibition
Xenical works locally in the gut as a lipase inhibitor.
It blocks fat-digesting enzymes, so part of the fat from a meal passes through unabsorbed instead of being taken into the body.
That is why it behaves differently from appetite suppressants and why it is often chosen by people who want a non-systemic weight loss medication.
Why diet matters with every dose
The medicine is most useful when paired with a reduced-calorie diet containing around 30% of calories from fat.
If meals are high in fat, Xenical side effects are more likely, and that is one of the main reasons people stop or switch treatment.
For many patients, the biggest surprise is that the tablets do not work well in isolation; the eating pattern matters with every dose.
Mechanism in brief
Meal fat → Xenical blocks lipase → less fat is absorbed → more fat leaves the body unabsorbed.
Xenical 120 mg vs alli 60 mg: choosing the right strength
Prescription and pharmacy access
Xenical 120 mg is the standard prescription version in the UK (POM).
alli 60 mg is the lower-dose pharmacy medicine (P), supplied under pharmacist supervision.
Who the 120 mg strength is for
It is the better-known option for adults who need structured support and are comfortable following the diet rules that go with it.
Brand, strength, route and packaging
| Brand | Strength | Route | Typical packaging |
|---|---|---|---|
| Xenical | 120 mg | Oral | Blister packs or bottles |
| alli | 60 mg | Oral | Blister packs or bottles |
Who Xenical is for, and who should not use it
Adult eligibility and BMI context
Xenical is generally used in adults who need weight-loss support alongside diet and lifestyle changes.
It is not recommended for children under 12 years because safety and efficacy have not been established.
In practice, UK pharmacists screen for suitability before supply, especially when the request is part of a broader weight loss medication conversation.
Absolute contraindications
It should not be used in chronic malabsorption syndromes such as cholestasis or inflammatory bowel disease, in people with hypersensitivity to orlistat or excipients, or while breastfeeding; it is also not recommended during pregnancy.
Precautions and red flags
- Kidney stone history
- Use caution because of the oxalate nephropathy risk.
- Chronic kidney disease
- Renal function should be monitored.
- Gallbladder or pancreatic disorders
- Extra caution is sensible because symptoms can overlap with side effects.
- Ciclosporin or warfarin use
- These medicines need monitoring because levels and INR may be affected.
How to take Xenical correctly
Standard adult regimen
The standard Xenical dosage for adults is 120 mg orally three times daily with each main meal containing fat.
The dose should be taken during the meal or up to 1 hour after it.
Taking more than 120 mg three times daily does not improve efficacy.
When to take a missed dose
If the meal was within the last hour, the missed dose can still be taken.
If more than 1 hour has passed after the meal, the dose should be skipped.
Doubling up is not recommended and usually just increases the chance of bowel side effects.
Dose timing rules
- Take with each main meal that contains fat.
- Take during the meal or within 1 hour afterwards.
- Skip the dose if the meal was more than 1 hour ago.
- Do not exceed 120 mg three times daily.
What results people can realistically expect
Typical weight-loss trajectory
People usually want to know whether Xenical works and how quickly the scales move.
Results vary, but they depend heavily on how closely the diet is followed and how much fat is eaten.
Xenical weight loss is best thought of as gradual support rather than dramatic early change.
Why results vary by diet adherence
When the diet is low in fat, treatment tends to be more tolerable and easier to stay with.
Longer-term use is possible if it is reviewed regularly.
The key review point is 12 weeks, and treatment should be discontinued if less than 5% of body weight has been lost.
Expected review milestones
| Stage | What to check | Typical action |
|---|---|---|
| Baseline | Weight, diet, suitability | Start only if appropriate |
| 12 weeks | Weight change and tolerability | Stop if under 5% loss |
| Ongoing | Diet adherence and side effects | Continue if benefit is clear |
Xenical side effects: what is common and what matters
Most frequent gastrointestinal effects
The most common Xenical side effects are bowel-related and can be very noticeable.
Patients often report oily or fatty stools, oily spotting, fatty or oily evacuation, increased defecation, faecal urgency, and flatulence with discharge.
Abdominal cramping, rectal pain, and nausea can also happen.
Less common symptoms
Some people also mention headache or upper respiratory infections, although these are less frequent than the gastrointestinal effects.
The good news is that the GI effects tend to peak early and usually become less troublesome when a low-fat diet is kept up.
That early pattern explains why some people feel the medicine is not for them, even when the issue is really the meal content rather than the capsule itself.
Mild vs moderate side effects
| Mild | Moderate |
|---|---|
| Oily or fatty stools | Faecal urgency |
| Oily spotting | Increased defecation |
| Fatty or oily evacuation | Flatulence with discharge |
| Increased defecation | Abdominal cramping, rectal pain, nausea |
Managing side effects in daily life
Low-fat meal planning
The simplest way to reduce troublesome bowel effects is to keep meals lower in fat and spread fat intake evenly across the day.
Reading labels helps, and very greasy takeaway meals are the classic trigger for problems.
Some people also need a multivitamin if advised by a clinician, because fat-soluble vitamin absorption may be affected.
When to seek pharmacist or GP advice
Ask for help if symptoms are severe, if diarrhoea persists, or if there are signs that something else may be going on.
That includes pain that does not settle, dehydration, or symptoms that feel out of proportion to the meal pattern.
Simple coping strategies
- Choose smaller, lower-fat meals.
- Spread fat intake across the day rather than loading it into one meal.
- Avoid very greasy takeaways and heavy sauces.
- Keep drinking enough fluid.
- Speak to a pharmacist about vitamin support if needed.
Interactions, warnings and monitoring
Medicines that need extra caution
Ciclosporin and warfarin are the two medicines that most clearly need extra monitoring.
For warfarin, INR monitoring matters.
For ciclosporin, levels should be watched carefully.
Kidney and liver considerations
Use caution in renal impairment because the medicine has not been specifically studied there, even though absorption is minimal.
Hepatic impairment also needs caution because specific studies are limited.
Patients with a history of kidney stones should be asked about it directly because of the oxalate nephropathy concern.
Monitoring priorities
- Renal function
- Check more closely in chronic kidney disease or stone history.
- INR monitoring
- Important if warfarin is used.
- Medication review
- Useful in older adults with polypharmacy.
Legal status and availability in the UK
Xenical (orlistat) 120 mg is a prescription-only medicine (POM) in the UK. The lower-strength alli 60 mg capsules are a pharmacy medicine (P).
In our online pharmacy, Xenical is available without a prescription, with discreet delivery to the United Kingdom in 9–21 days.
Storage, packaging and product authenticity
How to store at home
Store Xenical at 15 to 30°C, protect it from moisture and light, and do not freeze it.
Keeping it in the original packaging until use helps protect the capsules during pharmacy delivery and at home.
Genuine pack check
Check that the pack name, strength, and capsule count match what was supplied.
If anything looks damaged or unclear, contact the pharmacy before use.
Xenical alternatives and comparison with other weight-loss medicines
How Xenical differs from GLP-1 medicines
Xenical acts in the gut, while Saxenda and Wegovy/Ozempic are injectable GLP-1 medicines that work centrally and systemically.
That gut-only action is one of Xenical’s strengths, because it avoids systemic absorption to a large extent.
Its weakness is the diet-linked bowel effects, which are not a problem in the same way with every alternative.
When people switch from orlistat
Some people switch because they cannot keep meals low in fat.
Others prefer a tablet or injection approach, or need a medicine with a different tolerability profile.
Xenical versus common alternatives
| Medicine | Active ingredient | Route | Usual access |
|---|---|---|---|
| Xenical | Orlistat | Oral capsule | Rx |
| alli | Orlistat | Oral capsule | Pharmacy medicine (P) |
| Saxenda | Liraglutide | Injectable | Rx only |
| Wegovy/Ozempic | Semaglutide | Injectable | Rx only |
| Mysimba | Naltrexone/bupropion | Tablet | Rx only |
Frequently asked questions
Can you buy Xenical without a prescription?
No. Xenical 120 mg is a prescription-only medicine (POM) in the UK.
alli 60 mg is the lower-strength orlistat product, a pharmacy medicine (P) supplied under pharmacist supervision.
How long can it be used?
Treatment can be long-term, but it should be reviewed at 12 weeks.
If less than 5% body weight has been lost by then, it should be stopped.
Quick answers
- What if I miss a dose?
- Take it only if the meal was within the last hour; otherwise skip it.
- What if I take too much?
- No serious adverse reactions have been reported at high doses in the available data, but severe GI symptoms should be treated symptomatically.
- Who should avoid it?
- Anyone with chronic malabsorption, pregnancy, breastfeeding, or a relevant allergy.
- Is it the same as generic orlistat?
- Yes, Xenical is the branded form of orlistat, while orlistat capsules may be generic products.
Delivery across the United Kingdom
| City | Region | Delivery time |
|---|---|---|
| London | Greater London | 9–21 days |
| Birmingham | West Midlands | 9–21 days |
| Manchester | North West England | 9–21 days |
| Glasgow | Scotland | 9–21 days |
| Edinburgh | Scotland | 9–21 days |
| Liverpool | North West England | 9–21 days |
| Leeds | West Yorkshire | 9–21 days |
| Sheffield | South Yorkshire | 9–21 days |
| Bristol | South West England | 9–21 days |
| Cardiff | Wales | 9–21 days |
| Belfast | Northern Ireland | 9–21 days |
| Newcastle upon Tyne | North East England | 9–21 days |
| Nottingham | East Midlands | 9–21 days |
| Leicester | East Midlands | 9–21 days |
