Dr Ula: Peptides in New Zealand: access, the law, and what the evidence actually shows.
- 14 hours ago
- 5 min read
A clinical look at the peptides everyone's talking about — where things stand now, as heard on the Dom Harvey Podcast.
The conversation about peptides has outrun the evidence behind it. Podcasts, longevity influencers, and the arrival of the GLP-1 medicines have put a whole class of compounds in front of the public. In New Zealand right now, two things are true at once: these compounds are easier to get than they were a year ago, and the evidence behind them ranges from genuinely solid to almost nothing. Those are two different questions, access and evidence, and conflating them is where most of the public conversation goes wrong.
What a peptide actually is
A peptide is a short chain of amino acids, a signalling molecule that tells cells what to do. The body makes thousands of them. Insulin, isolated in 1921, was the first one turned into a medicine. Most of what's being talked about now is a lab-made version of a signal your body already uses, which is part of why these compounds tend to be well tolerated. They're also fragile, mostly broken down if you swallow them, which is why most are injected.
"Mimics something the body already makes" describes a mechanism. It says nothing about whether the thing works, or whether it's safe. That's the gap a lot of the hype lives in.
Peptides are not one category
This is the single most useful thing to understand: there is no such thing as "the evidence for peptides." It's a spectrum, and the ends of it are a long way apart.
At the top: **semaglutide and tirzepatide**, the GLP-1 receptor agonists. These mimic a gut hormone that regulates appetite and blood sugar. They're approved medicines with large randomised trials behind them, including cardiovascular outcome data. Nothing else in this conversation is in the same evidentiary league.
Below that: **thymosin alpha-1**, an immune-signalling peptide with a real human trial record and approval in a number of countries. It's also contraindicated in active autoimmune disease, the same mechanism that makes it useful for immune signalling can push an autoimmune condition in the wrong direction. That's not a footnote, it's a prescribing decision.
Then the **growth-hormone secretagogues**, ipamorelin and similar. Some human data, a coherent rationale, but limited long-term safety data. The specific thing I watch is IGF-1: chronic elevation is a growth signal, and population data links it to certain cancers. You don't use these without a baseline IGF-1 and ongoing monitoring.
Then the **repair peptides** — BPC-157 and TB-500 (a fragment of thymosin beta-4). The animal data is genuinely striking. There are no human randomised trials. None. And if you have an athlete in front of you: BPC-157 has been WADA-banned since 2022, under both the S0 and S2 categories. That's not a grey area either, it's a straightforward ban, and it needs to be said out loud every time this compound comes up.
At the far end: the **longevity peptides**. Mechanistically interesting, promising in animal models, and the human evidence is thin and largely confined to a small number of research groups.
There's a structural reason for this gap, and it's not sinister. Most of these compounds are naturally derived and can't be patented, so no company has a commercial reason to fund the trials that would settle the question. What's left is a set of compounds with plausible biology and real animal data, and for most of them, no confirmation in humans. For everything outside the GLP-1 class, that's a hypothesis. Not a treatment.
The legal position in New Zealand
Most peptides sold here are unapproved medicines, Medsafe hasn't evaluated them for quality, safety, or efficacy. Unapproved doesn't mean illegal to prescribe. Section 29 of the Medicines Act 1981 lets a prescriber supply an unapproved medicine to a named patient where there's a clinical rationale. That's the provision most peptide prescribing in this country sits on.
That framework changed recently. The Medicines Amendment Act came into force in November 2025. It widened who can prescribe unapproved medicines beyond doctors, and it introduced the "Rule of Two" verification pathway, a medicine can be approved here on the strength of full approval from two recognised overseas regulators. The operational rules for that pathway were finalised in May 2026. Both changes are now live.
What a legal pathway doesn't tell you: it confirms a clinician can supply the medicine and is taking clinical responsibility for that decision. It says nothing about whether the product has been quality-checked, and nothing about whether it's the right call for the person in front of you. Legal access answers a supply question. Whether something helps is a biology question. They're separate. Answering one doesn't answer the other.
One point gets misunderstood constantly, so I'll say it plainly: importing a prescription medicine without a valid New Zealand prescription is not the grey area people assume it is. Under the Medicines Act it can be an offence. Enforcement being inconsistent doesn't make it lawful.
Sourcing is where the real risk sits
This is where the regulatory gap actually bites. A lot of what's sold online as "research use only" is manufactured with no obligation to meet any pharmaceutical quality standard. Independent testing of grey-market peptides has repeatedly turned up wrong concentrations, contamination, and in some cases no active compound at all. Inject an unknown substance and the risks, infection, reactions to whatever the impurity is, a dose that has nothing to do with the label, aren't theoretical. The source matters as much as the compound.
What actually decides whether a peptide is appropriate
Clinically, the compound is rarely the first question I ask. What matters first is the person's biology and history, which means a baseline picture before anything else. For the growth-hormone peptides, that's knowing where IGF-1 already sits before you do anything that pushes it higher. More broadly, it's understanding what someone's inflammatory and metabolic markers are actually doing, and screening for the specific things that make a given peptide a bad idea for that person.
Those risks are concrete, not hypothetical. The pro-angiogenic repair peptides are a genuine concern in anyone with a history of malignancy, the same signalling that helps tissue heal can help unwanted tissue grow. Immune-stimulating peptides are the wrong direction in active autoimmune disease. None of these are set-and-forget. Used properly, they need a baseline and ongoing monitoring, full stop.
The take-home
Separate the questions that keep getting collapsed into one. Is it legal to access? Increasingly, yes. Has it been proven? For most of them, not yet. Is it right for this particular person, from a verified source, with a baseline and monitoring in place? That's an individual clinical decision, and it's the only one of these three that actually determines what happens to the patient.
Some of this is genuinely promising. Most of it is unproven. Being honest about which is which matters more than the enthusiasm for either end of the spectrum. Foundations first. Peptides are the icing, not the cake, and no amount of icing fixes a cake that was never built.
Dr. Ula
Co-Founder and Lead Physician, Autonomy
