Health and Medicine
PUBLISHED
Everybody’s talking about peptides. At least, in certain corners of social media they are. You may be bombarded with posts about them, or you may have no idea what we’re on about – it all depends on your algorithm.
But far from being simply a fringe topic in the wellness space, these substances are now getting attention from the foremost medical regulators in the world, so it’s probably time we paid a bit more attention.
What even are peptides, anyway?
“Peptide” is the general word for a short molecule built from amino acids. Stick enough peptides together in the right order, and you’ve got a protein.
There are countless peptides in the body with tons of functional roles. These ones, which are naturally produced in our cells, are called endogenous peptides. They include things like endorphins, the hormone vasopressin, and even insulin.
Exogenous peptides, on the other hand, are synthesized outside the body. Many have proven fantastically useful in medicine. Cyclosporine, for instance, is an immunosuppressant that helps treat autoimmune diseases and prevent transplant rejection – it’s derived from a peptide produced by fungi. The GLP-1 receptor agonists semaglutide and tirzepatide are also peptide-based drugs.
In short, peptides are absolutely not bad or dangerous in and of themselves – in fact, there are many we couldn’t live without.
The problem comes when people start experimenting with these substances off label, without medical supervision, and – in some cases – without any clinical testing data at all to back them up.
The peptide “boom”
The Guardian called it a “quiet medical revolution” in a recent video. Influencers with fridges full of little vials, casually injecting themselves on camera and telling their followers to “run don’t walk” to try out this latest obsession for themselves.
Communities of users on Reddit and Discord share tips for building the optimum “peptide stack” to achieve particular health and wellness goals. Longevity, weight loss, balanced hormones, and muscle growth are some of the talking points that come up time and again.
As the Guardian’s Adam Gabbatt showed in their investigation, it’s shockingly easy to purchase peptides on the online gray market – that’s buying goods that are authentic but not approved or regulated. However, as Gabbatt demonstrated, there’s no guarantee that products purchased in this way will contain the exact active ingredients in the exact amounts claimed.
Thanks to recent recommendations made to the US Food and Drug Administration (FDA), however, not everyone who is interested in trying peptides may need to resort to the gray market from now on.
Following a two-day meeting on July 23 and 24, a panel of FDA advisors voted to recommend relaxing FDA rules that have stood since 2023 and allow compounding pharmacies – pharmacies that prepare custom medications – to manufacture six peptides for patients with prescriptions.
Compounding pharmacies provide tailored medicines prepared on-site rather than dispensing existing commercial drugs. If your regular pharmacy has run out of a medication, a compounding pharmacy may be able to get the raw ingredients and mix it up for you. If you need a particular drug to be free from a certain allergen or in a different format, they can make you a modified version.
The formulations produced by compounding pharmacies aren't subject to FDA review, and the facilities aren't FDA-regulated, though they are supposed to only use FDA-approved ingredients.
These six peptides were part of a collection that such facilities were banned from manufacturing by the Biden administration due to “significant safety risks.” The turnaround isn’t a total surprise, given that current Health and Human Services Secretary Robert F. Kennedy Jr. has himself said he’s used peptides and wants to end their suppression.
The FDA isn't bound by these recommendations, so we’ll have to wait and see if the agency does allow broader access to these six peptides. If it does, it’s possible more could follow.
Some examples of other peptides are KPV, which is being evaluated for use in wound healing and inflammation; MOTs-C, which has possible uses in treating obesity and osteoporosis; and Semax, which is thought to help with migraine and trigeminal neuralgia.
For people with chronic conditions who haven't found relief with standard treatments, it’s easy to see why these unregulated alternatives might be appealing. Off-label use of drugs, after all, is hardly uncommon.
But there’s a big difference between a physician prescribing a drug that’s known to be safe for humans to treat a different condition versus purchasing substances that have never been trialed in humans and come with no guarantees they actually contain the ingredients they say.
The price of beauty
As well as medicinal compounds, some of the peptides touted online have more of a cosmetic focus.
One of the more well-known examples is Melanotan, a synthetic peptide that’s sold illegally as a tanning aid. It’s often taken as a nasal spray or an injection and works by stimulating the production of melanin in the skin.
According to Cancer Research UK, the drug is “not safe to use” due to lack of knowledge on long-term side effects and a lack of safety or quality control.
Copper peptides are also becoming popular for their supposed skin benefits. While peptides have been a prized ingredient in skincare products for some time – applying something topically in a cream or serum is very different from injecting it.
GHK-Cu is the usual formula, a short amino acid chain bound to a copper ion. It’s available legitimately in products that are applied to the skin and in treatments you can receive from a dermatologist, but people have also been tempted towards self-experimentation by the gray market offering.
“You don’t know what’s in the formulation. And if you overdose on copper, you can actually get toxicity from it,” dermatologist Dr Anetta Reszko told The Hollywood Reporter. “So knowing the source is crucial.”
“Not all copper peptides are created equal,” added Reszko.
A hidden risk to women?
Looking from the outside, there seem to be sex-specific strands to online peptide content. Much of the male-dominated content appears to center around muscle growth and optimizing strength and physique, while women may be hit more often with messaging about weight loss and skin aging.
In a recent article for The Conversation, Drs Adam Taylor and Michelle Swainson of Lancaster University flagged an issue that is seldom mentioned in peppy influencer "day-in-the-life" videos and discussion threads.
They write that “almost nobody is asking whether these substances affect men and women in the same way. The evidence suggests they do not.”
It’s unclear how certain peptides may impact the menstrual cycle, they point out. TB-500 – one of the six on the FDA advisors’ list – has been linked with breast and lung cancers, both of which disproportionately affect women.
And injectable GHK-Cu, they suggest, could pose a risk to the unborn child during pregnancy if taken in excessive amounts.
“Unregulated peptides are a gamble for anyone who takes them. But for women, a combination of biological, hormonal and anatomical factors stacks the risk higher still.”
Gambling with your health
Ultimately, the only way the questions around peptides will be resolved is if there are controlled human trials of these substances. Robust scientific evidence around their safety and use is needed if we’re to better understand the risks of side effects.
Regulation and quality control are vital too. Taylor – who recently chatted to IFLScience all about the anatomy of the human heart – told the BBC that bacterial contamination in gray market products could pose a serious risk to health.
Humanity already benefits from many peptide-based drugs, so there’s a perfectly good rationale for suggesting that others could be out there. But buying unregulated substances off the internet and injecting them into yourself – with only influencers to advise you – is a very high-stakes gamble.
“If this 'guinea pig' culture spreads, we risk a public health crisis of 'mystery' chronic conditions caused by these unregulated peptides that the traditional medical system isn't yet equipped to reverse,” general practitioner Dr Mike Mrozinski told the BBC.
The content of this article is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions.
