Who Can Use Weight Loss Injections — and the Myths Worth Clearing Up

The biggest misconception: you need to be severely obese to qualify

Most people who ask who can use weight loss injections assume the bar is very high. The idea that these medicines are reserved for people with extreme obesity is common, and wrong. Mounjaro is licensed for adults with a BMI of 30 or above, or a BMI of 27 or above if a weight-related condition is present. Wegovy carries the same thresholds. So someone who is moderately overweight and managing high blood pressure may well fall within the licensed population.

The conditions that count alongside BMI include type 2 diabetes, hypertension, dyslipidaemia, obstructive sleep apnoea and cardiovascular disease, conditions that are extremely common in the UK. Weight loss injections were developed precisely for this population, not only for those at the highest end of the BMI scale.

There is a further nuance that catches many people out. UK clinical guidance reduces the BMI threshold by 2.5 kg/m² for people of South Asian, Chinese, Middle Eastern, Black African or African-Caribbean backgrounds, recognising that metabolic risk presents at a lower body weight in these groups. If you want a thorough breakdown of who can take weight loss injections, including how these ethnic background adjustments are applied in practice, that page is a useful place to start before speaking to a prescriber. You can check your own figure using the NHS BMI calculator as a starting point.

Who is not suitable, and why the prescriber's role matters

Knowing the inclusion criteria is only half the picture. A prescriber also needs to confirm that no contraindication applies. Neither Mounjaro nor Wegovy is licensed for use during pregnancy, while breastfeeding, or when actively trying to conceive, and the MHRA advises using contraception throughout treatment and for a wash-out period before conception. For those taking oral contraceptive pills alongside tirzepatide specifically, adding a non-oral method of contraception for the first four weeks of treatment and for four weeks after each dose increase is recommended, because the pill's absorption may be reduced. NHS guidance on this point is clear and worth reading in full via NHS England's weight management injections guidance.

Neither medicine is licensed for anyone under 18. A history of medullary thyroid carcinoma or multiple endocrine neoplasia type 2, or a history of pancreatitis and certain gastrointestinal conditions, requires careful prescriber discussion before any treatment decision. This is exactly why a clinical assessment (not a tick-box form) matters. Our full eligibility guide covers these exclusions in detail.

One practical note: a BMI that meets the threshold does not guarantee a prescription. Prescribers assess the whole picture, including other medicines, relevant medical history and what the person actually needs. That assessment is what distinguishes a legitimate prescription route from any alternative.

NHS access versus private prescription, the practical difference

Many people who clearly qualify for weight loss injections are told by their GP that they are not yet eligible on the NHS. That is not because the medicine is wrong for them, it is because NHS access is being introduced in carefully managed phases. From June 2025, NHS England began rolling out tirzepatide (Mounjaro) via GP practices for adults with a BMI of 40 or above plus four or more qualifying conditions. The thresholds will broaden over time, but for now the NHS route excludes the majority of people who technically meet the licensed criteria.

A private prescription from a regulated online pharmacy is the alternative route for people who meet the clinical criteria but do not yet qualify for NHS treatment, or who prefer not to wait. This is what weight management through a private service looks like in practice. There are no referrals and no waiting lists, but the clinical rigour is the same. A GPhC-registered prescriber reviews every consultation. If you are curious about what that process involves, the practical steps of starting treatment are worth reading before you begin.

On the question of cost, it is worth understanding that a legitimate private prescription includes more than just the medicine. Exploring your treatment options at a regulated service will show you what is included in the price, consultation, clinical review, delivery and aftercare. That transparency matters when comparing providers.

What happens once you are confirmed as suitable

If a prescriber confirms suitability, treatment at nume is dispatched from our GPhC-registered pharmacy the same day, provided the consultation is submitted before midday on a working day. Your pen arrives by DPD the next working day in plain, unbranded packaging, no label on the outside to indicate what is inside, just a tracked parcel like any other. The pen itself is a pre-filled device; how long you use it depends on your progress and ongoing clinical reviews, not on an automatic renewal.

Treatment starts at the lowest dose to let your body adjust gradually, both Mounjaro and Wegovy follow an escalation schedule set by the prescriber, not self-administered. Every repeat order at nume is reviewed by a prescriber before dispatch; no prescription simply rolls over. Aftercare is available seven days a week if questions come up between reviews. If you want to understand what the medicines themselves do and how they compare, our overview of weight loss injection options covers the clinical differences clearly.

If you think you may fall within the licensed criteria, a free consultation with our clinical team is the right starting point. Check your eligibility and, if suitable, start your free consultation via our treatment page.