By Bhanvi Satija and Christy Santhosh

Jan 17 (Reuters) - Websites selling compounded versions

of popular weight-loss drugs from Novo Nordisk and

Eli Lilly ( LLY ) to U.S. consumers often do not inform patients

of the risks associated with these medicines, according to a

research letter published on Friday.

More than half of the 79 websites reviewed by the

researchers failed to disclose that their products were not

approved by the U.S. Food and Drug Administration, 37%

misleadingly implied FDA approval and 14% did not disclose they

were selling compounded products, which are essentially copies

of the name-brand drugs.

"The lack of FDA approval means there's no verification

of efficacy, no verification of safety," said Yale University

School of Medicine's Ashwin Chetty, who is one of the authors.

Roughly half of the sites did not inform patients about side

effects, warnings and precautions related to the drugs, and

about 40% overstated the drugs' benefits.

"I'm very worried about the internet compounding industry.

Some of it, I'm sure, is very high quality, but it's very hard,

if you are ordering things on the internet, to know exactly what

you're getting," outgoing FDA Commissioner Robert Califf said on

Thursday at a media roundtable.

U.S. laws allow compounding pharmacies and facilities to

produce compounded versions of FDA-approved drugs during

shortages of the branded version. A tight supply of Novo's

semaglutide and Lilly's tirzepatide - sold as Wegovy and

Zepbound, respectively, for weight loss - has fueled demand for

compounded versions.

Median first-month prices, including discounts, for the

compounded drugs ranged from $231 to $330. Those without

insurance coverage, however, pay $549 for Zepbound if ordered

directly from Lilly's pharmacy and $650 for Wegovy with a

discount card from Novo.

Chetty and other authors identified 79 websites between July

and September 2024 using Google Shopping to find businesses that

advertised branded and generic forms of the so-called GLP-1

medications.

Their research does not include "every single website in

existence that sells a compounded GLP-1," Chetty told Reuters.

"It's certainly possible that other websites have come

into existence since then," said Yale University's Alissa Chen,

who also authored the research.

Advertising of compounded drugs falls into a regulatory

"gray area" and requires stricter oversight, the researchers

said.

While direct-to-consumer advertising of compounded

weight-loss drugs is not "illegal", it hinders U.S. health

regulators' intent to provide patients access to safe medicines,

said T. Joseph Mattingly of the University of Utah College of

Pharmacy in a commentary published alongside the research.

Compounding laws "were not intended to create a window

of time where opportunistic vendors exploit a shortage to gain

market share and drive new demand through aggressive marketing

tactics," he added.

Advertisements for compounded products should be held to

the same standards as those of prescription drugs, Mattingly

recommended.

The authors of the study have received fees from Close

Concerns, a non-profit organization focused on diabetes and

obesity education. Mattingly has received grants from the

Alliance for Pharmacy Compounding and the FDA.

(Reporting by Bhanvi Satija and Christy Santhosh in Bengaluru;

Editing by Nancy Lapid and Anil D'Silva)