Lilly sues over 'illegal sales' of obesity drug retatrutide
Falsified retatrutide, branded as Alluvi, was seized by the UK authorities in a 2025 raid.
As reports surface around the world of knockoff copies of Eli Lilly's keenly anticipated weight-loss therapy retatrutide, the company has sued companies it accuses of participating in an illegal black market for the drug.
Lilly has filed six new lawsuits – naming US companies Aesthetic Envy, Astra, Legendary Peptides, Striker Pharmacy, Texas Peptides, and Lone Star Peptide as defendants – alleging they are selling black-market retatrutide to the public.
The defendants include a range of businesses, including medical spas, wellness clinics, compounding pharmacies, and online sellers, that often try to sidestep US regulations by labelling products as "research-use only."
It's part of a massive effort by the company to tackle the burgeoning trade in falsified versions of the 'triple G' agonist, which has shown stellar results in late-stage clinical testing – up to 24% weight loss over 48 weeks – but is yet to be approved in any jurisdiction worldwide.
Headlines about the efficacy of the drug have generated massive demand for what is becoming known as 'reta' through illicit sales channels, and there have been reports of serious side effects – including liver failure – among users sourcing them in this way.
Analysis of seized samples of the counterfeits has revealed incorrect dosages, ranging from zero to overdoses, and completely different active ingredients, such as insulin, which could be life-threatening. In addition, it is thought that many are made in non-sterile conditions and may be contaminated with microorganisms – particularly worrying for a drug that is injected.
There are numerous reports that organised crime networks have started manufacturing counterfeit retatrutide products – complete with fake brand names and bespoke packaging – on an internationally industrial scale. The products are often imported from China.
Last October, for example, the UK's MHRA seized 2,000 pen injectors purporting to contain retatrutide and Lilly's other weight-loss drug tirzepatide, along with tens of thousands of empty pens ready to be filled, from a single site.
"We take the responsibility of evaluating the safety and efficacy of our investigational medicines seriously," commented Lilly's chief medical officer, David Hyman. "What is being sold on the black market is not a medicine – it is entirely unverified, unapproved and not worth the risk."
The company is also calling on the entities that sellers use to conduct their illegal business – such as social media and e-commerce platforms, credit card companies, payment processors, and shipping and logistics carriers – to assist it in the crackdown on the illegal trade.
It said: "Drug regulators, customs agencies, law enforcement and other government authorities must treat the sale of unapproved retatrutide as the urgent public health crisis it is, prioritising enforcement and coordinating across borders to dismantle the criminal networks selling these drugs."
