GLP-1 medication: frequently asked questions

GLP-1 medications copy a natural gut hormone — glucagon-like peptide-1 — that helps the body manage appetite and blood sugar, increasing fullness and slowing how quickly the stomach empties.^[11] Taken alongside a reduced-calorie diet and more activity, they help some adults with obesity (or overweight plus a weight-related condition) lose weight and keep it off; several are also used in type 2 diabetes.^[8] Most are injections, but two oral options now exist: the Wegovy pill (oral semaglutide), MHRA-approved in June 2026,^[7] and orforglipron (Foundayo), approved in the US in April 2026.^[10]

The main members of the class are:

• Semaglutide — Wegovy (injection and now a pill) for weight loss, Ozempic in type 2 diabetes, and Rybelsus as an older diabetes tablet.^[11]
• Tirzepatide — Mounjaro, which acts on a second gut-hormone receptor (GIP) as well as GLP-1.^[12]
• Liraglutide — Saxenda, a once-daily injection for weight management.^[13]
• Orforglipron — Foundayo, a once-daily tablet (US-approved, not yet UK-licensed).^[10]

One caution: Ozempic is licensed in the UK for type 2 diabetes only, so weight-loss use is off-label, and the MHRA points people to the licensed options instead.^[9]

The difference is how the medicine is delivered, not a different drug family. Most GLP-1 medicines are injections under the skin — Wegovy and Mounjaro weekly, Saxenda daily.^[11] Two are tablets, and they differ. The Wegovy pill is oral semaglutide, taken first thing on an empty stomach with a sip of water and a wait before eating, because semaglutide is a peptide the stomach would otherwise break down.^[7] Orforglipron (Foundayo) is a small-molecule tablet, so the manufacturer says it can be taken any time of day, with or without food or water.^[10] Our Wegovy pill page covers the oral route.

There is no reliable way to rank all of them from separate trials, because each enrolled different people over different lengths of time. The individual averages are in the table: tirzepatide (Mounjaro) reached the highest figure at about 22.5% in SURMOUNT-1, semaglutide injection about 14.9% in STEP 1, and orforglipron about 12.4% in ATTAIN-1^[3][2][1] — but from different studies, so lining them up is not a real comparison. Where two have been tested head-to-head — tirzepatide versus injectable semaglutide 1mg in type 2 diabetes (SURPASS-2) — tirzepatide gave greater weight and blood-sugar reductions.^[4] The right choice for you is one a prescriber makes with you.

It varies a lot, and the figures are trial averages taken alongside diet and activity. In SURMOUNT-1 (72 weeks, obesity without type 2 diabetes), tirzepatide 15mg averaged about 22.5% weight loss, and 39.7% of that group lost at least a quarter of their body weight.^[3] In STEP 1, semaglutide 2.4mg injection averaged about 14.9%.^[2] Loss is generally smaller in people who also have type 2 diabetes: orforglipron averaged 12.4% in ATTAIN-1 (no diabetes) but 10.5% in ATTAIN-2 (with diabetes).^[1][20] A prescriber can explain what is realistic for you.

They are licensed only after large clinical trials, and are prescription-only because they need a prescriber's judgement. In the trials most side effects were gastrointestinal and mostly mild to moderate.^[1] The class also carries formal warnings — for example about acute pancreatitis, gallbladder problems and dehydration.^[12] The UK product information for the licensed injectables lists a serious allergy to the medicine as the main contraindication,^[11] whereas the US labels also warn about a possible thyroid-tumour risk seen in animal studies.^[21][22] So "safe" is not a simple yes or no — whether the likely benefit outweighs the risks for you is what a consultation decides.^[9]

The most common effects are gastrointestinal and tend to ease as the body adjusts. In the UK product information for the Wegovy injection, the "very common" effects (at least one in ten users) were nausea 43.9%, diarrhoea 29.7%, vomiting 24.5% and constipation 24.2%.^[11] In orforglipron's ATTAIN-1 trial, nausea affected roughly 29–36% of people (about 10% on placebo).^[1] Starting low and increasing the dose gradually — the "titration" every GLP-1 medicine uses — is designed to reduce this.^[12]

Not everyone, which is one reason they are prescription-only. In the UK, the official product information (the SmPC) for Wegovy, Mounjaro and Saxenda lists a serious allergy to the medicine as the contraindication, treating risks such as thyroid tumours, pancreatitis and gallbladder disease as precautions a prescriber must weigh.^[11][12] The US labels for semaglutide and tirzepatide go further and contraindicate a personal or family history of medullary thyroid carcinoma or the genetic syndrome MEN 2 — stronger than the current UK label.^[21][23] A prescriber also weighs pregnancy, other medicines and your wider history. Never decide for yourself — that assessment is what the consultation is for.

GLP-1 medicines are prescription-only in the UK, so the lawful route is always the same: a consultation with a qualified prescriber who decides whether the medicine is appropriate for you, and dispensing by a pharmacy registered with the General Pharmaceutical Council (GPhC). There is no legitimate way to buy them like an ordinary online product, and we do not recommend or link to any provider. If a supplier will skip the consultation, treat that as a warning sign, not a convenience.

Sometimes, but access is narrow and phased. A medicine must clear two gates: it has to be licensed by the MHRA, then recommended by NICE for NHS use — a licence alone does not mean the NHS pays for it.^[7] NICE recommends:

• The Wegovy injection (TA875) within a specialist weight-management service, for up to two years.^[14]
• Tirzepatide / Mounjaro (TA1026), final guidance published 23 December 2024, for adults with a BMI of 35 or more plus at least one weight-related condition.^[15]
• Liraglutide / Saxenda (TA664) within a specialist weight-management service.^[16]

Mounjaro's primary-care rollout is being phased in from 23 June 2025, with NHS England estimating roughly 220,000 people eligible over the first three years, starting with greatest clinical need.^[17] NICE lowers the BMI thresholds (usually by 2.5) for people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds.^[15] Your GP can explain the criteria. Because NHS access is limited, many people currently use regulated private prescribers instead — a prescriber still decides.

One GLP-1 pill for weight loss is licensed in the UK: the Wegovy pill (oral semaglutide 25mg), approved by the MHRA in June 2026 as the UK's first oral GLP-1 tablet for weight management.^[7] It is available on private prescription after a consultation, but was not on the NHS at approval — that would need a separate NICE appraisal.^[7] Orforglipron (Foundayo) is a different tablet: US-approved in April 2026 but not yet MHRA-licensed, so there is no lawful UK supply.^[10] Rybelsus is an older oral semaglutide for type 2 diabetes, not weight loss. Our Foundayo page tracks the UK position.

You should not, and in the UK you cannot do so lawfully. GLP-1 medicines are prescription-only, so any site selling them without a genuine consultation and prescription is operating outside the rules, and unlicensed products bought this way may be counterfeit or dangerous. The MHRA's #FakeMeds campaign explains how to check whether a supplier is legitimate.^[18] A safe route always involves a prescriber's assessment and a GPhC-registered pharmacy.

These medicines are studied and licensed as long-term treatment, taken alongside a reduced-calorie diet and more activity, and the trial results reflect people staying on treatment.^[8] Trials even report results two ways — the effect while people keep taking the drug, and the effect regardless of stopping — because the benefit is tied to continued use.^[3] NICE also builds in stop rules for NHS use: treatment can be stopped if a person has not lost a set amount of weight (commonly around 5%) in the specified window.^[14] Any decision to stop should be made with your prescriber, not abruptly on your own.

No supplement, tea or product sold as a "natural Ozempic" or "natural GLP-1" is a licensed GLP-1 medicine or a proven equivalent. GLP-1 medicines are specific pharmaceutical compounds tested in large trials.^[1] Over-the-counter products marketed to imitate them are not regulated as medicines and are not shown to work the same way. The one lever the trials relied on alongside the medicine was a reduced-calorie diet and more physical activity — which anyone can act on.^[8] If a product is sold as an unlicensed medicine claiming to treat obesity, be cautious and check the MHRA's #FakeMeds guidance.^[18]