aprott/iStock via Getty Images Australia will ban replicas of weight loss drugs, including Novo Nordisk's ( NVO ) semaglutide and Eli Lilly's ( NYSE: LLY ) tirzepatide, due to adverse events linked to the so-called compounded versions, which are made without regulatory oversight, the country's health minister, Mark Butler, said Wednesday. Demand for compounded alternatives of Novo's ( OTCPK:NONOF ) Ozempic and Lilly's ( LLY ) Mounjaro has taken off amid supply constraints for branded versions, which are indicated for diabetes but are increasingly used off-label for weight loss. Compounded drugs are personalized, cheaper versions of branded drugs based on the same active ingredient, also known as GLP-1 receptor agonists.

However, they are not clinically tested by regulators for safety, quality, or efficacy. "To keep Australians safe, new regulations will remove (GLP-1 receptor agonists), such as those being misrepresented and sold as replica Ozempic or Mounjaro, from the pharmacy compounding exemptions," Butler said. The ban will take effect on October 1, 2024, to give patients enough time to consult their doctors and seek alternatives.

Novo ( NVO ) and Eli Lilly ( LLY ) are also fighting compounded weight loss meds based on their branded drugs in the U.S. In July 2023, the Danish drugmaker sued a compounding pharmacy in Florida for allegedly producing and selling its own version of semaglutide.

However, a U.S. district court in Tampa, Florida, dismissed the lawsuit in October.