Who Owns Mounjaro? (October 2026)

01 · The short answer

Eli Lilly owns Mounjaro and tirzepatide

Eli Lilly and Company owns the Mounjaro brand and developed tirzepatide in-house. Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly. In the UK it is licensed for weight management in adults and for type 2 diabetes.¹

Lilly is a large, US-headquartered pharmaceutical company. It is responsible for making the medicine, its pre-filled pen device and the product information that comes with it. A shop selling Mounjaro is a supplier, not an owner.

02 · Why it matters

What ownership means if you want treatment

For a patient, ownership means two practical things. The medicine should trace back to Lilly, and it can only be supplied on prescription. Anyone offering Mounjaro without a consultation or prescription is not behaving like a legitimate supplier, whatever they claim about where it comes from.

You can check a pharmacy yourself on the GPhC register. Ours is registered under 9012878. We supply Mounjaro via official LillyDirect supply, meaning genuine KwikPens sourced from Eli Lilly's UK distribution, with all six doses in stock.

If you are ready to look at treatment, the Mounjaro pen prices and consultation page shows current prices, checked 10 October 2026. If you are still weighing up options, our weight loss clinic guide is a wider starting point.

Related guide: What pharmacy carries mounjaro.

03 · Lilly and tirzepatide

Lilly and tirzepatide: what it owns

Tirzepatide is the active ingredient and Mounjaro is the brand. Lilly discovered and developed the molecule itself, then took it through trials and licensing. The pre-filled pen, the name and the patient information are all Lilly's.

The product comes as a pre-filled multi-dose pen (KwikPen) in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.¹ The patient information leaflet in every box is Lilly's document too, and it is the right place to check anything about the medicine itself.¹³

04 · Why tirzepatide is different

Why tirzepatide stands apart from other GLP-1 medicines

Tirzepatide is the first treatment of its kind to activate two natural gut-hormone receptors at once: GIP and GLP-1. Together these help regulate appetite, slow how quickly the stomach empties, and improve the way the body responds to insulin.¹

This dual action is what distinguishes Mounjaro from single-action GLP-1 medicines such as semaglutide (Wegovy/Ozempic).¹ Those semaglutide products belong to a different company, Novo Nordisk. So a question like who owns GLP-1 has no single answer: GLP-1 is a type of hormone and drug class, not a product, and several companies make medicines that act on it. Our guide on who owns GLP-1 medicines goes through the main players.

05 · Who sells it in the UK

Who sells Mounjaro in the UK

Mounjaro is sold in the UK by regulated pharmacies and clinics, which dispense it against a prescription. Owning the brand and selling the pen are separate roles. Lilly supplies the market through its official distribution to licensed pharmacies.

To check any seller, look them up on the GPhC public register.¹² The MHRA also publishes counterfeit medicine alerts and runs the Yellow Card scheme, which is worth knowing about if you see unusually cheap pens advertised outside regulated channels.⁷

Read who sells the medicine for more on which pharmacies carry it.

06 · NHS and private access

NHS and private access to Lilly's medicine

Mounjaro is available on the NHS, but access is being phased in over several years. NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition, and the NHS primary-care rollout began in June 2025 with the highest-need groups first (initially BMI 40+ with four or more qualifying conditions).⁴⁶

Full rollout is expected to take years, which is why many people who meet the licensed criteria choose regulated private treatment rather than waiting.⁶ Both routes use the same Lilly medicine. The difference is who prescribes and who pays.

Not everyone can take it. Our guide on who can't take Mounjaro explains the main reasons a prescriber may say no.

07 · What the trials showed

What Lilly's main weight trial showed

In the SURMOUNT-1 trial of 2,539 adults, people taking tirzepatide alongside diet and exercise lost on average 15% of their body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone.²

These are trial averages. Individual results vary, and treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.² Trial averages do not predict your own result.

08 · Serious side effects

Serious side effects: when to get help straight away

Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing. If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion) — your prescriber may need to adjust those medicines.¹