A quarter of the 1180 presentations between July 2025 and September 2026 were young people aged between 16 and 24, figures from NSW Health published on Monday show.
Patients who had adverse reactions to the unregulated products showed up with abdominal pain, nausea and vomiting as well as chest pain, anaphylaxis and other allergic reactions.
Peptide popularity has grown from five presentations in July 2025 to 217 cases in September 2026, crossing age categories with 32 per cent aged 25-34 and 26 per cent aged 35-44.
Men made up 51 per cent of the patients over that period showing that peptides were not exclusive to a specific group.
Health Minister Ryan Park warned of the pressure put on public hospital at a time when they're stretched to their limits but also how dangerous the unregulated drug use was.
"We know that using these unapproved substances can come with real health risks, but it's particularly alarming to see the growing pressure they're placing on our health system," he said.
"Even when a product looks professional or comes in convincing packaging, that does not guarantee it is safe for use."
Lacking any authorisation, the skin injections are sold through an online black market with retatrutide quickly becoming the most popular product accounting for 71 per cent of the hospital presentations.
Some 38 per cent of injectors used the generic term peptide or other names of unapproved peptides and eight per cent mentioned a combination of both.
Peptide products are increasingly promoted through social media for everything from muscle growth, reverse ageing to weight loss and performance enhancement.
While some peptide products are approved by the Therapeutic Goods Administration, many products advertised online are not and may be unlawful to import, supply or advertise including BPC‑157, GHK‑Cu, TB‑500, retatrutide and CJC‑1295.
The rising craze spruiked by online celebrities prompted NSW Health Chief Health Officer Dr Kerry Chant to raise the alarm about how contents and strength may vary between products carrying the same label.
"We encourage people to discuss the risks, benefits and safer alternatives to products they see advertised with their usual general practitioner or qualified healthcare provider," she said.
"A professional looking website, a label, purity claim, reviews, or influencer endorsement is not proof of what is inside the product."
