Buying peptides online ‘a very real risk’ warns Endocrinologist
- endocrinology, peptides
- 1 min read
Victorian hospitals have recorded several cases of acute liver injury after peptide use, prompting a community safety message from a Monash Health Endocrinologist about the risks of unregulated peptides bought online.
‘There is a risk, a very real risk, when they start getting used without medical supervision,’ said Endocrinologist Professor Peter Fuller AM, who also works at the Hudson Institute of Medical Research.
‘You don’t often know what’s in there, and I can’t tell you what the worst effects are, because I don’t know what’s going to be in that vial you’ve bought.’
The Victorian Department of Health said the serious cases of liver toxicity were discovered in patients who had injected an unregulated peptide product labelled as Retatrutide.

Additional contaminants may have contributed to the observed liver toxicity in the products.
Retatrutide is an experimental drug not approved for sale as a safe medical product in Australia.
Prof Fuller said anything bought online, outside of the advice of a GP and a pharmacist, was considered unregulated and not medically safe.
‘It needs to be coming from a pharmacist, a chemist,’ he said.
‘It needs to be an approved medication. That will guarantee that it has been properly tested.’
Are there safe peptides online?
Prof Fuller, who works in Monash Health’s Endocrinology Unit, said the biggest risk is that consumers buying peptides online don’t know what’s in these products.
‘As soon as you start buying things that haven’t come through that medical pathway… you don’t know what the quality is,’ he said.
‘You don’t know what other things are in there, and that gets dangerous.’
Unregulated peptides are increasingly promoted on social media promising easy, rapid weight loss, muscle gain, glowing skin, tanned skin, and more.
This has prompted warnings from the Therapeutic Goods Administration (TGA), which regulates advertisements for therapeutic goods, including both approved and unapproved peptide products.
It also approves products that are safe for medical use.
‘If the drug is licensed for use in Australia by the Therapeutics Goods Administration, then it is safe to use,’ Prof Peter Fuller said.
‘That should be under medical supervision because many of these things – even the ones that will be beneficial – may have a range of side effects that one needs to be aware of.’
Prof Fuller said if you are thinking about using a peptide product, you should first see your general practitioner for advice.

What is a peptide?
A peptide is a broad term that includes a wide range of drugs, including some that are tested and safe.
‘Peptide is just a very general, generic term. It’s a bit like saying cars,’ said Prof Fuller.
Peptides are made up of amino acids, usually chains of 20 to 40 amino acids joined together.
‘Some of them are known hormones. Some of them are molecules that signal in the brain,’ he said.
Some peptides have been approved by the TGA and are routinely prescribed by doctors like Semaglutide, known as Ozempic.
‘The poster child at the moment would be Semaglutide or Ozempic, and that’s got proven benefits in weight loss in diabetes,’ Prof Fuller said.
‘The natural peptide in that, GLP-1, was first identified in the mid 80s and it took probably 20 years for that to be turned into a safe product.’