Orlistat for weight management treatment
Orlistat is a prescription-only medicine used as part of a structured weight management programme in adults, alongside a reduced-calorie, balanced diet and increased physical activity.
It works by reducing the absorption of dietary fat in the digestive system. Treatment suitability and dosage are determined by a UK-registered prescriber following an individual medical assessment.
How to access orlistat through DoktorABC
Complete an online consultation and medical questionnaire.
A UK-registered prescriber will review your answers and, if orlistat is considered clinically appropriate, issue a prescription.
Important information. DoktorABC UK is a digital health platform that connects patients with independent, UK-registered prescribers. DoktorABC UK does not itself provide medical care, issue prescriptions or dispense medicines. All clinical decisions are made by the UK-registered prescriber following an individual medical assessment.
What is Orlistat?
Orlistat is a prescription medicine used to support weight management in adults who are overweight or obese, as part of a comprehensive weight management plan that includes dietary changes and increased physical activity.
Unlike other weight management medicines, it acts locally in the digestive tract and does not affect the central nervous system or cardiovascular system.
What is the active substance in Orlistat?
Orlistat belongs to a class of medicines known as lipase inhibitors. It works by blocking enzymes called lipases, which are responsible for breaking down dietary fat in the intestine.
As a result, approximately 30% of fat consumed in meals is not absorbed and passes through the intestine undigested, contributing to a reduction in overall calorie intake.
Who may be considered for treatment?
Orlistat may be considered for adults following medical assessment, particularly those with:
- A BMI of 30 or above.
- A BMI between 28 - 29.9 with at least one weight-related health condition.
Treatment must be combined with a reduced-calorie, nutritionally balanced diet and long-term lifestyle changes, including regular physical activity. Treatment outcomes vary between individuals and depend on adherence to dietary guidance. A UK-registered prescriber will assess your overall health, medical history and current medicines before prescribing.
What dosage of Orlistat is recommended?
The usual dose is 120 mg up to three times daily, taken with each main meal containing fat. If a meal is skipped or contains no fat, that dose can be omitted. Always follow the dosage instructions provided by your UK-registered prescriber.
How is Orlistat taken?
Swallow the capsule whole with water, immediately before, during or up to one hour after a main meal. Orlistat is only effective when dietary fat is present. Following a lower-fat diet is recommended to help reduce gastrointestinal side effects
When should Orlistat not be used?
Orlistat should not be used if you:
- Are breastfeeding.
- Have chronic malabsorption syndrome.
- Have cholestasis (a condition in which bile flow from the liver is reduced or blocked).
- Are allergic to orlistat or any of its ingredients.
Always inform your UK-registered prescriber about your full medical history before starting treatment.
Possible side effects
Like all medicines, orlistat can cause side effects, although not everyone experiences them.
Very common side effects
- Oily or fatty stools.
- Increased urgency to pass stools.
- Flatulence with discharge.
- Soft or loose stools.
Common side effects
- Abdominal discomfort.
- Rectal pain.
- Bloating.
- Fatigue.
- Changes in menstrual cycle.
Reducing dietary fat intake can help minimise side effects.
If you experience side effects, inform your UK-registered prescriber.
Reporting side effects (UK)
Suspected adverse reactions can be reported via the MHRA Yellow Card scheme.
Clinical evidence
Clinical studies have evaluated the safety and effectiveness of orlistat as part of weight management programmes.
Published evidence indicates that orlistat reduces dietary fat absorption by approximately 30% at the recommended dose. When combined with dietary and lifestyle changes, average weight loss over 12 months has been shown to be modest but clinically relevant in some individuals.
These study results are provided for informational context only and do not represent expected or guaranteed outcomes for individual patients.
Orlistat active substance and excipients
Active substance:
Other ingredients:
- Sodium carboxymethyl starch (Type A)
- Microcrystalline cellulose
- Highly dispersed silicon dioxide
- Gelatine
- Sodium lauryl sulphate
- Titanium dioxide (E171)
- Indigo carmine (E132)
Marketing authorisation holder and manufacturer details can be found in the UK patient information leaflet.
Patient information leaflet
The UK patient information leaflet for orlistat is available via the electronic Medicines Compendium (eMC).
