Have the right BMI
Anyone with a body mass index (BMI) of 28 or higher
What is Alli?
Alli is an over-the-counter weight loss medication that contains orlistat as its active ingredient. It's specifically designed to help people achieve weight loss by preventing the absorption of up to 25% of your dietary fat, alongside a mildly lower-calorie, lower-fat diet. Unlike other weight loss medications that suppress appetite, Alli works directly in your digestive system.²
Is Alli right for you?
Given the way Alli works, it may not be suitable for those who don't match the criteria. For example, those with chronic malabsorption syndrome or liver disease, pregnant or breastfeeding women, and anyone under the age of 18 would not be suitable for treatment.
Those who are suitable for treatment with Alli must meet the following criteria:⁴
How does Alli work?
Alli works by blocking around 25% of the fat you eat from being absorbed by your body. Its active ingredient, orlistat, targets the enzymes in your digestive system that break down fat.² By disabling these enzymes, Alli prevents some of the fat you consume from being stored. Istead, it passes through your system and is naturally eliminated.²
Because Alli works only in the gut and has minimal absorption into the bloodstream, it often has fewer side effects for people than other weight loss medications.³ When combined with a balanced diet and regular exercise, it can support long-term weight loss.
How to take Alli
The recommended dose for Alli is 60 mg three times a day with each fat-containing meal, either during the meal or within one hour after eating. If a meal is missed or it doesn’t contain fat, you can safely skip that dose.²
Taking more than the recommended dose may not enhance its effectiveness. Since Alli can interfere with the absorption of fat-soluble vitamins (A, D, E, K), it’s advised to take a multivitamin supplement at bed time to maintain proper nutrient levels.²
| Week | Dose (mg) | Frequency |
|---|---|---|
| Week 1 | 60 | Once a day: start with one dose with your main meal to test tolerance. |
| Week 2 | 60 | Twice a day: take with lunch and dinner; monitor for any digestive discomfort. |
| Week 3 | 60 | Three times a day: begin the full dosage schedule, with breakfast, lunch, and dinner. |
| Maintenance | 60 | Three times a day: continue with each fat-containing meal. |
How effective is Alli?
Alli has been clinically proven to support effective weight loss when combined with a reduced-calorie diet. In a large 2-year clinical trial involving 743 patients with a BMI of 28–47, those taking orlistat (the active ingredient in Alli) lost, on average, 10.2% of their body weight during the first year, which is significantly more than the 6.1% lost by the placebo group.⁵
Patients who continued taking orlistat into the second year regained half as much weight as those who switched to placebo, demonstrating its effectiveness not only for weight loss but also for preventing weight regain.⁵ In addition to weight reduction, participants experienced improvements in cholesterol levels, glucose, and insulin concentrations.⁵ When used correctly alongside a balanced diet, Alli can be a powerful tool for achieving and maintaining weight loss.
What are the side effects of Alli?
Like all medications, Alli has some side effects. These differ from person to person. All of the side effects are listed in the product information leaflet that comes with the medication and should be read before use. Some of the more common ones are listed below:
| Gastrointestinal | Other |
|---|---|
| Oily spotting on clothes | Anxiety |
| Gas with discharge | Hypersensitivity reactions such as rash or urticaria |
| Urgent or increased bowel movements | Hepatitis |
| Fatty, oily stools | Gallstones |
| Flactulence | Mild rectal bleeding |
| Soft stools | Abdominal pain |
Meet the experts
Numan’s Weight Loss Programme is crafted by a team of specialists who understand the multifaceted challenges of weight management. Leveraging the latest insights in metabolic science, appetite regulation, and psychology, our experts create tailored treatments and strategies designed for lasting success.
Our approach includes the use of Alli, a lipase inhibitor that reduces the absorption of dietary fats, making it easier to achieve your goals. Alongside support from healthcare professionals and lifestyle coaches, the programme is personalised to adapt to your unique needs at every stage.
Dr Luke Pratsides
Head of Medical
MBBS MSc MRCGP MFCI
Dr Bryony Henderson
Medical Director
MBBS BSc MRCGP DFFP
Jess Uffindell
Registered Nutritionist
BANT CNHC BSc (Hons)
Mo Dekmak
Clinician
MPHARM PGDIP IPRESC
Shivani Sharma-Savani
Prescribing Lead
MPharm PGCert PCert IP
Faye Townsend
Senior Health Coach
AfN BSc BDA PGDIP BPS
OTHER SOLUTIONS
Understanding your options: weight loss treatments
Medicated weight loss solutions vary in their mechanisms and effectiveness. While Alli reduces fat absorption, other treatments, such as GLP-1 receptor agonists like Wegovy, suppress appetite to help you feel full longer and manage cravings. Choosing the right treatment depends on your individual needs and health goals.
Health coaching designed for you
Health coaching forms the core of our programme, aiming to foster lasting lifestyle changes. Paired with Alli’s fat-blocking support, our coaches guide you in building practical, sustainable habits across nutrition, exercise, sleep, and mindset.
While Alli helps to reduce fat absorption, our coaches enhance these benefits with advice on balanced meals, enjoyable physical activity, and effective routines for better health. Together, they provide the support needed to make meaningful progress and achieve your goals.
Tackling obesity: a new approach
Obesity is a complex condition influenced by a range of biological, psychological, and environmental factors.6 At Numan, we recognise the importance of addressing these challenges with science-backed solutions like Alli, which actively reduces fat absorption. This medication acts as a stepping stone towards building healthier habits and achieving sustainable weight loss.
With obesity impacting millions across the UK, Numan offers a holistic programme that combines medical expertise with personalised guidance. By focusing on the root causes of weight gain, we help you take control of your health, with support tailored to your unique needs and goals.
I feel I can live a longer, happier life with less risk of cardiovascular issues. I've struggled with being overweight for many years, so the impact has been life-changing.
I discovered an old bag of clothes and couldn’t believe how many of them fit me where I would have had no chance before. I feel amazing. I think I look much better than I ever did.
I want to be in good shape to enjoy life. But be happy as I’m doing it, rather than miserable. And I think I’ve managed that with the programme.
FAQS
Your questions answered
KNOWLEDGE
Weight loss: what you need to know
References
1 (*) Based on weight loss in orlistat-treated patients after 1 year. Rössner, S., Sjöström, L., Noack, R., Meinders, A.E., Noseda, G. and (2000), Weight Loss, Weight Maintenance, and Improved Cardiovascular Risk Factors after 2 Years Treatment with Orlistat for Obesity. Obesity Research, 8: 49-61.”
2 Bansal AB, Patel P, Al Khalili Y. Orlistat. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2025.
3 Anderson JW. Orlistat for the management of overweight individuals and obesity: a review of potential for the 60-mg, over-the-counter dosage. Expert opinion on pharmacotherapy. 2007;8(11): 1733–1742.
4 NHS. Obesity - treatment. nhs.uk. https://www.nhs.uk/conditions/obesity/treatment/ [Accessed 20th May 2025].
5 Sjöström L, Rissanen A, Andersen T, Boldrin M, Golay A, Koppeschaar HP, et al. Randomised placebo-controlled trial of orlistat for weight loss and prevention of weight regain in obese patients. European Multicentre Orlistat Study Group. Lancet. 1998;352(9123): 167–172.
6 Lee A, Cardel M, Donahoo WT. Social and Environmental Factors Influencing Obesity. [Updated 2019 Oct 12]. In: Feingold KR, Anawalt B, Blackman MR, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-.
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