Medical experts have warned of significant health risks to members of the public after it emerged that an experimental weight loss medication, which has no regulatory approval worldwide, is being sold on the Irish black market.
During investigations related to the illegal sale of weight loss products, RTÉ Investigates discovered and filmed a woman based in Tuam, Co Galway, selling Retatrutide.
The woman, who is not a qualified doctor, advertises the product as "the most powerful weight loss treatment."
Retatrutide is an experimental medicinal product which is not approved for use anywhere globally, and still in clinical trials in the US. Such medication is often years from being deemed safe for use or achieving regulatory approval.
RTÉ Investigates arranged to meet the woman advertising the product on social media in her Galway home. On arrival she supplied a package with a clear glass vial and several hypodermic needles, before offering to inject the substance there and then.
"This is Retatrutide," she said. "I have my medical supplier. I checked it and I have this supplier since last September. Basically, every two weeks, I have to order more because people are coming back."
Having been provided with no manufacturer or product information, RTÉ had the vial's contents independently analysed at a laboratory at University College Dublin. The results indicated it did contain Retatrutide.
Watch: A preview clip from 'RTÉ Investigates: Black Market Weight Loss'
In a statement, Eli Lilly, the manufacturer of Retatrutide, said the product has not been reviewed or approved by the US Food and Drug Administration, the European Medicines Agency, or any regulatory agency anywhere in the world and therefore at this time no one can sell it for human use.
It added that any product falsely representing itself as a Eli Lilly product "may expose patients to potentially serious health risks".
"That is completely mad," Professor Donal O’Shea told RTÉ, having viewed the undercover footage.
Prof O’Shea is a consultant endocrinologist and the HSE National Clinical Lead for Obesity.
"So that kind of delivery of a medication to an individual would have you struck off the Medical Council register if you did it once. So, I can't get my head around that. You were offered a clear injection from an unlabelled bottle, and you weren’t told where it was manufactured - it doesn't really get any worse than that."
'Skinny pens’
Earlier this year RTÉ Investigates examined the beauty industry and the sale of Botox-type products by people not legally allowed to do so.
During that investigation, evidence of another illegal trade alongside it in the industry began to emerge - the sale of what sellers online refer to as 'skinny pens'.
These medications are commonly referred to as GLP1s because they mimic the GLP hormone in the body which regulates appetite, thereby reducing hunger and making the user feel full.
"In Ireland we have access only to GLP1 Saxenda and Ozempic and it's prescribed for people with diabetes and increasingly for people with obesity," said Prof O’Shea.
"These are prescription only drugs. So, they will be prescribed by registered medical practitioners or advanced nurse prescribers to people who meet the eligibility criteria, and they will be dispensed exclusively through your pharmacy."

In the course of the six-month investigation, RTÉ Investigates found several individuals, who are not doctors, nurses, or pharmacists, selling prescription only weight loss pens and medication directly to the public. In some cases, individuals were offering to inject people with the substances, despite not being qualified to do so.
The products included weight loss pens from Turkey, counterfeit Semaglutide pens and unlabelled glass vials containing clear liquid which were provided in packs with hypodermic needles.
In most cases the products are openly advertised on social media as "skinny pens" or "skinny jabs".
In one case, RTÉ Investigates discovered a seller based in Dublin, who was advertising not only on her personal social media but also on many buy and sell sites too. At an undercover meeting she sold a pen which she said she purchased "outside the EU".
RTÉ later established the woman travels to Turkey and has done so eight times so far and purchases 30-35 pens per trip.
Pharmacist, and former president of the Irish Pharmacy Union, Kathy Maher, told RTÉ there would be increased risks to the user of such products related to how it was transported.
"To transport medicines that are fridge only products through heat and Turkey, through airports, through people with an ice pack, it already puts the quality of the product in question," she said.
"And then to supply to patients that are going to inject it, It's a huge risk... We have to remember she is not a pharmacist, she is not qualified to discuss medicine, and it must be used under medical supervision," Ms Maher added.
In a statement, the Health Products Regulatory Authority, the body responsible for policing GLP1 medication and other prescription medication in Ireland said it has repeatedly warned of the health risks associated with the use of GLP1s that have been obtained outside of the legitimate pharmacy setting and without a prescription supplied by a doctor providing professional oversight.
The HPRA added that sellers are "drawn to the illegal trade in these new medicines because it presents a lucrative opportunity to exploit high demand and limited supply."
Product seizures
This year the HPRA has detained 1,469 units of GLP1 products, close to three-times the volume detained in 2023. In addition, up to the end of November, 456 web addresses linked to GLP1 products were removed or amended. That is more than double the 172 web addresses removed or amended in 2023.
The HPRA also confirmed to RTÉ that from the beginning of January 2022 to the end of November 2024, it has been notified of 385 reports of suspected side effects associated with a medicine containing a GLP1 substance with 28 of these requiring a hospital attendance. It is not clear how many of these relate to products purchased on the black market.
Watch the full documentary ‘RTÉ Investigates: Black Market Weight Loss’ tonight on RTÉ One at 9.35pm and RTÉ Player.