Experimental weight loss pill seems to be more potent than Ozempic

An experimental pill looks set to cause more weight loss than existing injectable treatments such as Ozempic, Wegovy and Mounjaro, based on early trial results reported on 7 March.

The medicine, called amycretin, caused people to lose 13 per cent of their weight over three months, more than twice the amount seen with Ozempic and Wegovy specifically. “This approach seems to be a little bit more exciting, from the limited data that we have,” says Daniel Drucker at the University of Toronto in Canada.

The results are from a placebo-controlled trial lasting three months, so it is too soon to know how amycretin stacks up against the other medicines for long-term effectiveness and safety, says Drucker, who wasn’t involved in the trial but has consulted for the manufacturer Novo Nordisk, as well as other pharmaceutical firms.

The diabetes drug Ozempic and the weight loss drug Wegovy are two brand names for the compound semaglutide. They work by mimicking a gut hormone called GLP-1 that is normally released after eating. This makes people feel full, reduces their appetite and boosts the release of the blood-sugar-regulating hormone insulin.

Semaglutide leads to the loss of about 15 per cent of body weight after it has been taken for one year, although weight then plateaus and people need to continue the injections long term or it tends to creep back up.

Another weight loss injection was launched last year, called Mounjaro, also known as tirzepatide or Zepbound. This mimics GLP-1 and an additional gut hormone called GIP. Mounjaro seems to lead to people losing about 21 per cent of their weight over the first year and five months of use, before their weight loss plateaus.

Amycretin, however, mimics GLP-1 and a different hormone called amylin, which seems to make it more potent still – at least over the first three months of treatment. People taking amycretin lost 13 per cent of their weight in this period, Novo Nordisk announced today, according to a report by Reuters. Those taking placebo pills lost 1 per cent. This is more than the equivalent figures for Wegovy and Ozempic, of 6 per cent, and for Mounjaro, of about 7.5 per cent.

However, we can only know for sure how the drugs measure up long term when they are compared under exactly the same circumstances in a single study, says Drucker. “These are not head-to-head trials.”

Another caveat is that medicines that work by mimicking GLP-1 have been used for more than a decade to treat type 2 diabetes and so their safety profile is well understood, which isn’t the case for an amylin mimic.

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Novo Nordisk has also said that amycretin’s side effects were similar to those of Wegovy, which tend to be nausea, vomiting and diarrhoea, especially for people who increase the dose too quickly.

Being available in tablet form would be a great advantage for people who don’t like injections, says Daniel Chancellor at global pharmaceutical business analysts Citeline. “An oral pill is very attractive.”

As well as these three medicines, other weight loss drugs that mimic other gut hormones are also in development.