What monitoring do weight-loss patients actually need?

What are you monitoring a weight-loss patient for?

Four things: response, tolerability, safety events and continued suitability. Response is whether the weight is coming off, measured against a verified baseline. Tolerability is the gastrointestinal burden that affects more than one in ten patients. Safety events are the rare, serious problems the MHRA has written warnings about: pancreatitis, gallbladder disease, dehydration, an eye condition and pregnancy exposure. Continued suitability is whether the dose, the interactions and the person's circumstances still justify the next supply.

The duty to monitor is not optional and it is not new. The GPhC's guidance for pharmacist prescribers, updated in April 2025, requires a prescriber to decide what monitoring is needed after prescribing. The prescriber must record the arrangements for follow-up and monitoring, and assess and monitor the outcome. For high-risk medicines prescribed online, which include weight-loss medicines, the necessary monitoring arrangements must be in place before prescribing. The GMC's prescribing guidance says the same to doctors at paragraph 92: suitable arrangements must be in place for monitoring, follow-up and review.

What changed in 2026 is that the GPhC started marking pharmacies down for the absence of it. Its April 2026 review of weight-management inspections and concerns lists, among the failures recorded under standard 1.1, pharmacies that lacked "follow up arrangements to ensure ongoing treatment remained appropriate and safe". Its concerns data describes medication "automatically titrated without clinical review, even when people had submitted information as to why this may be inappropriate, for example adverse effects". The recommended actions include appropriate ongoing clinical follow-up. Monitoring has moved from good practice to inspection criterion.

What baseline must be recorded before the first supply?

The figures you will measure change against, and the history that decides whether treatment is safe. The GPhC requires the person's weight, height or BMI to be verified independently of what they typed, through video, an in-person assessment, clinical records or the GP. A phone call alone is not appropriate for weight-loss supply. That verification process is the subject of our guide to the verification duties; this article picks up once it is done. The table lists what a defensible baseline record contains and where the requirement comes from.

Blood tests are the item people ask about most, and the answer is that no licence or regulator requires a routine panel for a non-diabetic adult starting a GLP-1 medicine for weight. The duty is to decide what monitoring this patient needs and to record why. That points to testing where the history calls for it. An HbA1c where diabetes is possible. Renal function where the person is at risk from dehydration. Glucose monitoring for the diabetic patient on insulin or a sulfonylurea. A blanket policy is not required. A blank space where the decision should be is a records failure.

How often should patients be reviewed?

At every dose step, at three months and at six months, then at an interval the prescriber sets and records. No regulator publishes a fixed timetable. The structure comes from three places: the product licences, NICE's appraisals and the GPhC's expectation of periodic re-verification.

The licences build reviews in through titration. Under its summary of product characteristics, semaglutide (Wegovy) starts at 0.25 mg once weekly. It rises through 0.5 mg, 1 mg and 1.7 mg to a 2.4 mg maintenance dose, with at least four weeks at each step. Tirzepatide (Mounjaro) starts at 2.5 mg once weekly for four weeks, then 5 mg. It can rise in 2.5 mg increments after at least four weeks at each dose, to a maximum of 15 mg. Each step is a decision that the current dose is tolerated and the next one is clinically indicated. That is a review by another name.

NICE sets the decision point. Its tirzepatide appraisal, TA1026, says treatment may stop if less than 5 per cent of starting weight has been lost after six months at the highest tolerated dose. Its semaglutide appraisal, TA875, has the same 5 per cent at six months rule and limits NHS use to a maximum of two years within a specialist multidisciplinary service. A private service is not bound by NHS commissioning, but a prescriber who continues a patient past six months with no meaningful response needs a recorded reason. The GPhC's 2023 patient safety spotlight on weight-loss services, still current, listed continued prescribing despite no weight loss after 12 weeks among the poor practice inspectors found.

The GPhC's FAQs add one practical concession. Photographs are unsuitable for verifying weight at the first supply, because they can be edited. For follow-up prescriptions, where other means verified the initial weight, photographs may be appropriate. The condition is that "there would need to be a mechanism to check how the person's weight-loss is progressing and monitor and verify it periodically". Periodically means a schedule, and a schedule means something fires when it is missed.

What must happen at each dose step?

A clinician must look before the dose goes up. The complaint the GPhC recorded was not that patients were titrated. It was that they were titrated automatically, by a system that advanced the dose on a calendar while the patient was reporting adverse effects. The review's actions for prescribers ask for the clinical rationale for each repeat supply and dose change to be documented, and for every supply to be reviewed individually for suitability.

In practice a dose-step review covers five things. Is the current dose tolerated, and what gastrointestinal effects has the patient had? Has any red-flag symptom occurred? Has weight been re-verified, and is the trajectory consistent with the reported dose? Has the patient changed other medicines or become pregnant? And, for women on oral contraception who take tirzepatide, has the contraception advice been repeated? The MHRA's guidance says to add a barrier method for four weeks after starting and for four weeks after any increase in dose. Tirzepatide slows gastric emptying and can reduce absorption of the pill.

Holding a dose is a valid outcome. So is stepping down. A record that shows every patient escalated on schedule, with no holds and no reductions, is not a record of monitoring. An inspector who has read the April 2026 review will recognise it.

Which side effects need action, and what action?

The MHRA has issued a run of safety communications since October 2024, and together they define the counselling and the response a service must be able to evidence. The table draws on the MHRA's GLP-1 guidance, updated on 5 February 2026, and the drug safety updates it links to.

The pancreatitis update deserves emphasis because the numbers are not small. Between 2007 and October 2025 the MHRA received 1,296 Yellow Card reports of pancreatitis with GLP-1 and dual GIP/GLP-1 medicines, including 19 fatal cases and 24 of necrotising pancreatitis. The update also tells clinicians to ask about privately prescribed GLP-1 medicines when a patient presents with abdominal pain, because they "may not appear on the patient's medical history". If your service does not tell the GP, the hospital may not know what it is treating.

On mental health, the MHRA has concluded that the available data does not support a causal link between GLP-1 medicines and depression or suicidal thoughts. The GPhC review's recommended actions ask for specific consideration of vulnerable groups, including people with eating disorders, at every individual review.

When should treatment stop?

When it is not working, when it is doing harm, or when the person's circumstances have changed. The clearest rule is NICE's: treatment may stop if less than 5 per cent of starting weight has been lost after six months at the highest tolerated dose. Both TA1026 and TA875 carry it. Harm-driven stops are listed in the table above, and two of them are absolute: confirmed pancreatitis, and confirmed optic neuropathy on semaglutide.

Stopping is also a supply decision the pharmacy sees. A patient who stops responding to review requests but keeps ordering is not being monitored, whatever the SOP says. The GPhC's 2023 spotlight listed insufficient mechanisms to prevent oversupply among poor practice. A defensible service has a rule for what happens when a review is missed: a recall, then a hold on further supply until the review is done, and a record of both. How you run those recalls is covered in our guide to reminders and recalls in Dataforge PMR.

Weight regain after stopping is common, and a patient leaving treatment needs advice on maintaining changes and where to get support. Record the stop, the reason and the advice, and share it with the GP in the same way as the start.

How do you evidence follow-up for inspection?

With a record for each patient and a log for the service. The April 2026 review's standard 1.6 finding was that records "lacked the level of detail required to demonstrate safe and clinically appropriate decision making". Inspectors now ask to see the follow-up for individual patients, not the policy. What the GPhC acts on when it does not find it is set out in our article on how the GPhC is policing online weight-loss supply.

Who is responsible: the prescriber or the pharmacy?

Both, and the split is clearer than services sometimes pretend. The prescriber owns the clinical decision: what to monitor, the arrangements, the review and the outcome, under the GPhC's prescriber guidance and the GMC's paragraph 92. The prescriber also owns sharing information with the patient's regular prescriber, or recording the justification when the patient refuses consent.

The pharmacy owns assurance. The April 2026 review marked pharmacies down where they could not show that the third-party prescribing services they worked with had risk assessments and clinical safeguards in place. Follow-up is one of those safeguards. If your pharmacy dispenses against a platform's prescriptions, you need evidence that the platform reviews patients at dose steps, chases missed reviews and stops treatment when it should. The broader framework for working with remote prescribers is in our guide to the remote prescribing rules for high-risk medicines.

The superintendent sits across both. The GPhC's prescriber guidance says incentives and targets must not compromise professional judgement. The January 2026 inspection framework says prescribers must not have a financial incentive to issue prescriptions that may not be appropriate. A review process whose only ever output is "continue and escalate" will be read as evidence about incentives, not about patients.

Key takeaways

FAQs