The TGA is once again urging doctors against initiating patients on semaglutide, less than three months after relaxing its prescribing advice, as limited supply struggles to keep up with surging demand.

On Thursday, the regulator said supply constraints for all strengths of semaglutide (Ozempic) would persist for the rest of the year and throughout 2024.

It followed advice from manufacturer Novo Nordisk that demand “had accelerated in recent months”, particularly for the low-dose (0.25mg/0.5mg) version, with a rapid increase in off-label use.

As a result, the TGA said prescribers should not start new patients on the drug “unless there are no suitable alternatives or there is a compelling clinical reason to do so” — a reversal from its advice in June.