Who can use semaglutide for weight loss — and who shouldn't

The clinical trial that shaped who prescribers look for

The STEP 1 trial, published in the New England Journal of Medicine, enrolled adults with a BMI of 30 or above, or a BMI of 27 or above with at least one weight-related condition, and no type 2 diabetes. You can read more about what the research found in our overview of once-weekly semaglutide in adults with overweight or obesity, which covers average weight reduction over 68 weeks on semaglutide 2.4 mg of around 15%. That enrolled population maps almost directly onto the licensed population today: the trial was designed to define who benefits, and regulators used it to do exactly that. Understanding who was included in STEP 1 is therefore a practical guide to who semaglutide is intended for.

NICE built on that evidence when it recommended semaglutide for NHS use under technology appraisal TA875. The recommendation applies to adults with a BMI of 35 or above and at least one weight-related comorbidity, used for a maximum of two years within a specialist weight management service. The private licensed threshold is lower (BMI 30, or 27 with a qualifying condition) and that is the frame that applies to a private consultation. Neither number exists in isolation: they are the entry point, not the whole assessment.

One misconception worth setting aside gently: semaglutide is not a medicine for people who want to lose a modest amount of weight for cosmetic reasons. The MHRA and DHSC are explicit that GLP-1 medicines are not assessed or licensed for quick or cosmetic weight loss. The licence reflects a clinical population living with obesity or excess weight affecting their health, and prescribers apply that framing.

Which health conditions strengthen a semaglutide application

For people with a BMI between 27 and 29.9, the licensed eligibility depends on the presence of at least one weight-related condition. The conditions that qualify include type 2 diabetes, prediabetes, high blood pressure, dyslipidaemia (raised cholesterol or triglycerides), obstructive sleep apnoea, non-alcoholic fatty liver disease, and osteoarthritis. Cardiovascular disease also counts. That list reflects conditions where excess weight is a direct driver of harm and where meaningful weight reduction carries documented health benefit.

A prescriber reviewing your consultation considers not only which conditions are present but how they interact, what medicines you already take, and whether any aspect of your history changes the risk profile. That is why the full clinical picture of who can take semaglutide covers more ground than a BMI calculator alone. Certain combinations (such as a history of pancreatitis, or active gallbladder disease) require particular care and may affect whether semaglutide is suitable for you.

Ethnic background matters here too. UK guidance recognises that health risks associated with excess weight emerge at lower BMI values in people from South Asian, Chinese, Middle Eastern, Black African or African-Caribbean backgrounds. Prescribers apply the adjusted thresholds in line with that evidence, which means eligibility is assessed relative to your background, not just a universal cut-off.

Who should not use semaglutide

Some contraindications are absolute. Semaglutide is not licensed for use in people under 18. It is not recommended during pregnancy, while breastfeeding, or when trying to conceive, the advice is to use effective contraception throughout treatment and for a defined wash-out period afterwards, discussed with the prescriber before starting. Anyone with a personal or family history of medullary thyroid carcinoma, or the rare condition multiple endocrine neoplasia type 2, must not use semaglutide.

Beyond those hard stops, there are situations that require careful prescriber judgement. Severe kidney or liver impairment, a history of serious eating disorders, and certain psychiatric conditions all factor into the risk assessment. This is precisely why the rules around who can legally supply semaglutide require a prescription: clinical screening is not an administrative step, it is the process that keeps people safe. The NHS patient information for semaglutide on the NHS website sets out the contraindications in plain terms and is worth reading before a consultation.

If you have any doubt about whether a condition in your history is relevant, raise it during the consultation, that is the right moment for it. Prescribers at nume read every consultation the same day it is submitted; a real clinician, not automated software, considers your answers in full.

NHS access versus a private prescription, what the eligibility gap means in practice

The gap between NHS and private eligibility is real and affects a lot of people. On the NHS, NICE TA875 limits semaglutide to a two-year course within a specialist weight management service, with a BMI threshold typically starting at 35 plus a comorbidity. Waiting lists for those services can run to months or years. The private licensed threshold is lower and there is no waiting list when treatment comes through a regulated online pharmacy. If you are partway through a course and have questions about timing, our guide on whether you can use semaglutide after 28 days covers what you need to know about pen expiry and safety.

Cost is a genuine part of the decision. The Wegovy price comparison guide explains what private treatment typically costs and what the headline figures do and don't include. At nume, one transparent price covers the consultation, prescription, treatment and next-working-day delivery, no subscription, no repeat automatic charge, and every order clinically reviewed before it is processed.

If you're weighing up what route makes sense, the weight-loss treatment overview sets out how Wegovy sits alongside other licensed options in the UK. For people who meet private eligibility but are still uncertain, a free consultation with our prescribers is the most direct way to get a clear answer. There's no obligation, and the assessment itself is thorough. You can start your free consultation here, a prescriber will review it the same day.