Orlistat
In brief
- Orlistat 120 mg capsules (Xenical) are a prescription-only medicine (POM) in the UK; the 60 mg capsules (Alli) are a pharmacy medicine (P).
- Orlistat is used for weight loss and weight maintenance as part of a reduced-calorie, lower-fat diet and lifestyle programme. It works by inhibiting gastrointestinal lipases, reducing the absorption of dietary fat in the gut.
- The usual dose is 120 mg three times a day with main meals for prescription use, or 60 mg three times a day with meals for Alli. If a meal is missed or contains no fat, the dose should be skipped.
- It is taken by mouth as hard gelatin capsules.
- Orlistat begins working from the first doses by blocking fat absorption in the intestine, although visible weight-loss effects usually become noticeable only after days to weeks of use.
- The effect lasts for the duration of its presence in the gut, covering the meal with which it is taken; it is used long term as part of an ongoing weight-management plan.
- There is no specific alcohol interaction known, but alcohol can add extra calories and may undermine weight-loss efforts, so moderation is advisable.
- The most common side effects are oily spotting, flatulence, urgent or frequent bowel movements, fatty or oily stools, abdominal discomfort, diarrhoea, and abdominal cramping.
- Would you like to try orlistat without a prescription?
Basic orlistat information
- INN (international nonproprietary name): Orlistat
- Brand names available in the United Kingdom: Alli (60 mg); Xenical (120 mg); generic orlistat
- ATC code: A08AB01
- Forms and dosages: Capsules 60 mg and 120 mg, oral
- Manufacturers in the United Kingdom: Roche (Xenical); GlaxoSmithKline (Alli); generic 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: 120 mg capsules: prescription-only medicine (POM); 60 mg capsules: pharmacy medicine (P)
- Standard dosage per condition: 120 mg three times daily with main meals for obesity or maintenance; 60 mg three times daily with main meals (pharmacy medicine)
- Dosage adjustments: Not recommended under 12 years; no specific elderly adjustment; use with caution in hepatic or renal impairment
- Typical treatment duration & regimens: Long-term use alongside a moderately low-fat, reduced-calorie diet
- Instructions for missed doses & overdose: Skip if a meal is missed or contains no fat; do not double dose; large overdoses have not resulted in severe toxicity and supportive care is recommended
- Storage & transport guidelines: Store below 25°C, protect from moisture and direct sunlight
- Absolute contraindications: Chronic malabsorption syndromes, hypersensitivity, pregnancy, and not recommended for children under 12 years
- Relative contraindications & monitoring: History of oxalate kidney stones, diabetes, thyroid disease, ciclosporin use
- Common side effects: Oily spotting, flatulence, frequent or urgent defecation, fatty or oily stool, abdominal discomfort, diarrhoea, faecal incontinence, abdominal pain or cramping, headache
- Notable competitors: Liraglutide, semaglutide, naltrexone/bupropion
What orlistat is and how it feels in real life
Orlistat in brief
Orlistat is the International Nonproprietary Name, and the best-known brands are Alli and Xenical.
It is sold as hard gelatin capsules in 60 mg and 120 mg strengths.
The early experience often catches people off guard, because oily spotting, urgency, and changes in stool can appear quickly if meals are too fatty.
That is not a sign the medicine is acting in the brain like a stimulant; it is acting locally in the gut and the diet needs to change with it.
Brand names and pack sizes
Alli means 60 mg capsules, while Xenical means 120 mg capsules.
Common pack sizes are 21, 42, 84, and 90 capsules, depending on the brand.
| Brand | Strength | Pack size | Typical use case |
|---|---|---|---|
| Alli | 60 mg | 21, 42, 84, 90 capsules | Weight-loss support (pharmacy medicine) |
| Xenical | 120 mg | 21, 42, 84, 90 capsules | Prescription weight-loss treatment |
| Generic orlistat | 60 mg or 120 mg | Varies by supplier | Generic orlistat in either strength |
How orlistat works in the gut
Gut-only action and why that matters
Orlistat works by blocking fat absorption in the intestines rather than suppressing appetite.
That is the key reason it belongs to the lipase inhibitor group and why it is used for weight management rather than as a stimulant.
It is not absorbed in significant amounts systemically, so its action remains in the gut.
What this means for meals and expectations
If meals are high in fat, the chance of unwanted bowel effects increases.
That is why a reduced-calorie diet with lower fat intake is part of the treatment, not an optional extra.
Many patients notice the pattern quickly: fat eaten leads to less fat absorbed, and greasy meals lead to more GI side effects.
For that reason, orlistat tends to suit people who are prepared to adjust food choices rather than hope for an appetite suppressant.
Legal status and availability in the UK
Orlistat 120 mg capsules (Xenical) are a prescription-only medicine (POM) in the UK. Orlistat 60 mg capsules (Alli) are a pharmacy medicine (P) supplied under pharmacist supervision.
In our online pharmacy, orlistat is available without a prescription, with discreet delivery to the United Kingdom in 9–21 days.
Who orlistat is for, and who it isn’t for
Best-fit patient profile
Orlistat is mainly used by adults who want weight loss or weight maintenance as part of a structured lifestyle programme.
It is used long-term alongside a moderately low-fat, reduced-calorie diet.
That makes it suitable for people who can keep to the dietary plan and are looking for a treatment that supports, rather than replaces, behaviour change.
When it is not appropriate
Some people are disappointed because they expect quick results without changing meals.
If the diet part is not realistic, the medicine is much less useful and the side effects can be frustrating.
- Contraindication
- A situation where the medicine should not be used, such as pregnancy or chronic malabsorption syndromes.
- Relative contraindication
- A situation where extra caution is needed, such as a history of oxalate kidney stones or thyroid disease.
- Monitoring
- Checks done during treatment to make sure the medicine remains safe and effective.
Orlistat is not recommended for children under 12 years.
Dosage strengths and how they’re used
Standard dosing by indication
The standard prescription dose for obesity and weight loss maintenance is 120 mg three times daily with main meals.
The dose for Alli (60 mg) is three times daily with main meals.
If a meal is skipped, or if it contains no fat, the dose should be skipped as well.
Practical dosing habits
That simple rule matters in real life, because many people eat irregularly during workdays, takeaways, restaurant meals, or snack-led evenings.
Carrying capsules for meals out can help with adherence, but there is no point taking a dose with a fat-free meal.
| Strength | Frequency | Typical product examples |
|---|---|---|
| 60 mg | Three times daily with main meals | Alli, generic orlistat |
| 120 mg | Three times daily with main meals | Xenical, generic orlistat |
How to take orlistat safely day to day
Meal-based use and missed doses
Orlistat is best taken with meals that contain some fat.
If a meal is missed, or contains no fat, the dose should be skipped and not doubled later.
That is especially important when routines change, because doubling up does not improve results and only complicates the treatment plan.
Overdose and counselling points
Large overdoses have not resulted in severe toxicity, and symptomatic, supportive care is recommended.
In pharmacy counselling, the practical message is usually simple.
- Take it with main meals only.
- Keep dietary fat lower.
- Skip the dose if the meal has no fat.
- Do not double dose after a missed meal.
That is the sort of advice a patient should expect from weight-loss counselling before starting treatment.
Common side effects
The common real-world effects
The side effects that people talk about most are oily spotting, urgency, and stool changes that can feel embarrassing if they happen at work or after a meal out.
Other mild effects include flatulence, frequent or urgent defecation, fatty or oily stool, and abdominal discomfort.
Moderate effects can include diarrhoea, faecal incontinence, abdominal pain or cramping, and headache.
What increases the chance of side effects
Higher-fat meals make the symptoms more noticeable, and poor diet adherence usually makes the medicine harder to tolerate.
Many users change food choices quickly once the pattern becomes clear, particularly after greasy restaurant meals or takeaway nights.
| Symptom | Likely trigger | Self-care note |
|---|---|---|
| Oily spotting | Higher-fat meal | Reduce meal fat next time |
| Urgency or frequent defecation | Dietary fat and poor adherence | Plan meals more carefully |
| Fatty or oily stool | Greasy food | Keep meals lower in fat |
| Abdominal discomfort or cramping | GI effects from treatment | Seek pharmacy advice if persistent |
Interactions, cautions, and monitoring
Medicines and conditions to flag
Some medicines and conditions need extra attention before or during treatment.
Ciclosporin levels may fall, so monitoring is needed if both medicines are used together.
Diabetes treatment may need adjustment as weight reduces, and thyroid disease should be monitored for hypothyroidism.
A history of oxalate kidney stones is a concern because the risk may increase.
There is no formal dose adjustment for hepatic or renal impairment, but caution is sensible because data are limited.
What pharmacists and prescribers monitor
In the UK, pharmacy screening questions, GP review, repeat prescriptions, and electronic prescriptions all help make treatment safer.
- Monitoring
- Checking medicine effects, side effects, and relevant tests during treatment.
- Relative contraindication
- A factor that does not always stop treatment, but should prompt caution.
- Drug interaction
- When one medicine changes the effect or level of another.
Treatment duration and what success looks like
Long-term use with lifestyle change
Orlistat is used long-term and continued as long as clinically meaningful weight loss is maintained.
It works best as part of a wider weight-management programme, not as a standalone solution.
That means food choices, activity, and adherence matter just as much as the capsules themselves.
How patients judge progress
Many people judge success by waist change, clothing fit, a steady weight trend, and fewer cravings for fatty meals.
Some also notice that the treatment nudges them into better habits because greasy foods become less appealing.
Weight loss + diet + activity + adherence is the practical formula most patients end up using.
Orlistat versus other anti-obesity medicines
How it compares in practice
Common alternatives include liraglutide, semaglutide, and naltrexone/bupropion.
The differences are usually about injections versus capsules, side-effect profiles, and personal preference.
That matters because some people want a capsule, while others are prepared to consider a GLP-1 agonist if it suits their treatment plan better.
Why some people still choose Orlistat
Orlistat remains popular because its action is non-systemic, the capsule format is familiar, and a lower-strength 60 mg version is available from pharmacies.
It also has a clear dietary link, which can make the treatment plan easy to understand for patients who want practical weight-loss support.
| Medicine | Class | Main appeal |
|---|---|---|
| Orlistat | Lipase inhibitor | Capsule format and gut-only action |
| Liraglutide | GLP-1 agonist | Injected prescription treatment |
| Semaglutide | GLP-1 agonist | Prescription obesity treatment with injection route |
| Naltrexone/bupropion | CNS/opioid antagonist combination | Oral prescription alternative |
Storage, packaging, and product handling
Storage
Orlistat should be stored below 25°C, protected from moisture and direct sunlight.
No special transport conditions are needed unless the packaging says otherwise.
Shelf life and packaging checks
A quick check of the pack on arrival is worth doing.
- Make sure the blisters or bottle are sealed.
- Check the expiry date.
- Confirm the capsule count matches the pack size.
- Check that the strength on the label is correct.
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 |
| Leeds | West Yorkshire | 9–21 days |
| Glasgow | Scotland | 9–21 days |
| Edinburgh | Scotland | 9–21 days |
| Liverpool | North West England | 9–21 days |
| Bristol | South West England | 9–21 days |
| Newcastle upon Tyne | North East England | 9–21 days |
| Nottingham | East Midlands | 9–21 days |
| Sheffield | South Yorkshire | 9–21 days |
| Cardiff | Wales | 9–21 days |
| Belfast | Northern Ireland | 9–21 days |
| Oxford | South East England | 9–21 days |
