This is the new ‘wonder’ ingredient found in everything from weight-loss jabs to A-list treatments and ‘bio-enhancement’… but as the ‘Wild West’ market thrives, our experts reveal the warnings you can’t ignore

Peptides are the new ‘wonder’ ingredient in beauty products and health supplements.

On TikTok, videos tagged #peptidetherapy have been viewed more than 20million times. And A-listers including Jennifer Aniston, Rebel Wilson and Serena Williams are receiving weekly peptide injections for a variety of reasons such as better skin, weight control and muscle recovery.

Peptides are the latest buzzword in medicine, too, driving the multi-million-pound success of weight-loss injections such as Ozempic and Wegovy – but scientists believe they could also lead to breakthroughs for everything from cancer and autoimmune diseases to deadly superbugs.

But these genuine medical advances have created a halo effect for peptide products now being sold online as supplements, or injections offered by wellness clinics and salons (see box) marketed as ‘longevity boosters’ or for better sleep, sharper minds and glowing skin.

And because, technically, these peptides aren’t classed as medical treatments, experts warn that this is creating a grey area that lets unlicensed drugs slip through the net. A related problem is the illegal trade in peptides, such as the tanning peptide melanotan – sold illegally online as injections or nasal sprays. It has been linked to serious side-effects including nausea, high blood pressure and changes in moles, and potentially increased melanoma risk.

Earlier this year, a woman from King’s Lynn in Norfolk told the BBC she had ended up in hospital ‘unable to breathe’ after having a severe reaction to the peptide spray.

The problem is that ‘the GLP-1 drugs [such as Wegovy] have given credibility to peptides of all kinds’, says Aidan Goggins, a pharmacologist and expert in supplements.

‘Social media influencers simplify that into peptide supplements, with “the same results without injections”.

‘In reality, most peptide supplements can’t survive digestion or penetrate skin.

‘So while the marketing often sounds medical, the biology isn’t there. Ultimately, if a peptide truly has medical effects, UK law treats it as a medicine.

While peptides occur naturally in the body, artificial versions can be made in the lab (usually using engineered yeast or bacteria)

‘And if it doesn’t have medical effects, your skin or gut will just treat it as lunch – with little benefit or effect.’

In short, when it comes to peptides, it can be very hard to work out what’s legitimate and what is just hype – or, indeed, potentially harmful.

So what exactly are peptides – and why is there so much buzz around them?

Peptides are tiny molecules that form hormones or proteins: in our bodies they act like messengers, telling cells to grow tissue, repair bone or release hormones.

While they occur naturally in the body, artificial versions can be made in the lab (usually using engineered yeast or bacteria).

In the case of drugs such as semaglutide (found in Wegovy/Ozempic), the peptides mimic a hormone, GLP-1, which tells the brain when we have eaten enough.

Another peptide drug, teriparatide, is used to treat osteopororis, strengthening fragile bones by instructing calcium and bones to re-grow.

There are also peptide cancer drugs already in use. Some switch off the hormones that feed a tumour (such as goserelin or leuprolide for prostate and some breast cancers). Others calm the tumour’s growth signals so it slows or shrinks (octreotide or lanreotide for lung or pancreas tumours).

There may be more soon to come. Researchers at the University of Southampton reported in Nature Communications this year that specially engineered peptides can boost the strength of someone’s own antibodies against cancer, triggering a more powerful immune attack.

What makes peptides exciting is that they sit in a sweet spot – their size and shape means they can target tricky areas of the body’s chemistry that normal drugs can’t reach. For example, some new peptide drugs are being designed to mend damaged heart tissue after a heart attack.

They also work very precisely, so often have fewer side-effects. What’s more, because peptides are natural to the body, they tend to break down safely.

Be wary of skin repair injections

While in medicine peptides are used to treat disease, the beauty world sells them as the next ‘cure’ for ageing.

TikTok is awash with ‘peptide routines’ and glossy before-and-after videos. Beauty clinics advertise ‘peptide facials’ and injections to ‘rebuild’ collagen or ‘reset’ tired skin.

Peptides in skincare products are very different from those in medical treatments. Beauty peptides are tiny, lab-made fragments that mostly sit on the skin’s surface. Medical peptides, such as the peptides in blockbuster GLP-1 drugs, are usually bigger, more complex molecules that work deep inside the body (see main story).

You will find beauty peptides in serums under names such as Matrixyl, Argireline or copper peptides.

Dr Angela J. Lamb, an associate professor of dermatology at Mount Sinai Hospital in New York, says some peptide creams and cosmetic treatments do work, but only on the surface of the skin – and only with time.

One of the first commercially available cosmetic peptides was Matrixyl, in 2000. It’s now used as an anti-ageing ingredient in dozens of mainstream skincare lines, such as Olay, Boots No7 and The Ordinary. The lab-made peptide signals skin cells to produce more collagen, the protein that keeps skin firm and smooth.

Improvements are modest rather than dramatic, but consistent across small studies. In one 12-week trial with 93 women, a cream containing Matrixyl significantly reduced fine lines and wrinkles compared with a placebo. University of Nottingham imaging studies published in 2021 have shown the peptide can penetrate the outer skin layer – important for meaningful improvement to skin.

Meanwhile, copper peptides – often listed on labels as GHK-Cu – deliver tiny amounts of copper to enzymes involved in skin repair and firmness. They’re applied topically as serums or creams and are marketed for sun-damaged, thin or irritated skin. Research suggests they can boost collagen and reduce inflammation, though results are modest and depend on regular use.

Argireline – available since 2001 and often marketed as a ‘Botox in a bottle’ – can slightly relax the tiny muscles that cause expression lines. But the effects are ‘mild and temporary’ says Dr Lamb. Any promises of instant wrinkle-removal or ‘miracle’ anti-ageing are wide of the mark.

Some salons now inject peptide blends, for ‘cell repair’. ‘Topical peptides are generally safe, but once you start injecting them it becomes a medical procedure,’ says Dr Lamb.

‘If they’re not handled properly you can get inflammation or infection. These should be done in a medical setting, not a beauty salon.’

She adds: ‘Some peptides can improve hydration, texture and support collagen production, but they’re not miracle workers. They don’t lift or rebuild the skin. People need realistic expectations.’

But that doesn’t mean they’re risk-free. And experts are concerned that the success of peptides in clinical trials is being exploited by private clinics and to sell products on social media.

Many of the versions of peptides promoted by influencers and clinics are still experimental and have not been tested in clinical trials.

‘There’s virtually no oversight of these products, especially when sold online or used outside medically licensed clinics,’ warns Niharika Duggal, a professor of immune ageing at Birmingham University. ‘People are being offered peptide injections and supplements with no guarantee of quality, safety, or correct dosing. Without proper regulation and medical supervision, it’s a dangerous free-for-all.’

For example, some ‘wellness’ clinics promote experimental peptides such as BPC-157 and TB-500. One of the most popular is BPC-157, a lab-made fragment of a stomach protein of interest for its potential to heal wounds and tendons.

TB-500 is a synthetic fragment of thymosin beta-4, a natural protein involved in cell growth and repair, and is sometimes marketed online for muscle recovery or injury healing. But neither has a licensed medical use. Both are classed as ‘research peptides’ and cannot legally be sold as a supplement or advertised to the public for a specific medical condition. Instead, wellness expressions such as ‘repair’, ‘longevity’, or ‘metabolic health’ are used.

It’s easy to find websites selling BPC-157/TB-500 supplements. And these online products are where a ‘real risk lies’, says Aidan Goggins, a co-founder of lifespan specialist Kyros Nutrition.

He adds: ‘Unlicensed research peptides which have no official medicinal status, and therefore no quality control, can frequently contain impurities or inaccurate concentrations, and regulators warn that they can trigger immune reactions due to contamination, for instance.’

However, Haroon Shaikh, 52, from Nottingham, says taking experimental peptides via a private clinic has been life-changing. Two years ago, he was diagnosed with a benign tumour in his spinal cord. The surgery to remove it saved his life but left him with severe nerve damage, mostly on his left side.

His left leg dragged, his hand was weak and numb and he also couldn’t raise his right arm above his shoulder. ‘My balance was shot,’ he says. ‘Stairs were difficult and I couldn’t run at all.’

His neurosurgeon warned that whatever strength he regained in the first year would probably be all he would ever recover, as nerve fibres repair and regrow slowly and scar tissue that forms over time can block further repair.

Eighteen months later he was still struggling to walk steadily and felt stuck.

An online search led him to the Healand Clinic in Leicester and to Dr Omar Babar, who offered experimental peptide therapy marketed as a ‘bio-enhancement’. ‘The mix we used with Haroon includes BPC-157, CJC-1295 and Ipamorelin [all peptides],’ says Dr Babar, who is also a consultant in emergency medicine working at University Hospitals of Leicester NHS Trust. ‘They’re synthetic versions of molecules the body already makes, designed to encourage repair and regeneration.’

Haroon started on a once-daily (self-administered) injection into his thigh – five days on, two off, repeated over several weeks.

He also made some lifestyle changes, such as more sleep, more exercise, vitamin D and iron supplements, as well as taking NAD+ (a molecule found naturally in all cells that provides energy) and CoQ10 (an antioxidant, also found in the body).

‘Within months I was jogging again. Now, I’m back in the gym and can run without thinking about it.’

His neurosurgeon later described his recovery as ‘remarkable’.

Haroon believes it was the peptides rather than anything else that really moved the dial. But this is just one case.

‘We’re seeing promising improvements in patients with nerve-related problems, though it’s early days,’ admits Dr Babar. ‘We need proper data. Anecdotes aren’t enough.’

Dr Babar, who is now setting up a small clinical trial, worries that ‘the lack of regulation means people who are trying to do things properly get put in the same category as those who aren’t’.

Other experts concur. Professor Atul Malhotra, a sleep and respiratory specialist at the University of California, San Diego, who led research that found that another peptide, tirzepatide (used in weight-loss drug Mounjaro) eased sleep apnoea (which causes breathing to stop intermittently) by about 60 per cent, warns: ‘These are not “just” salon treatments.

‘They’re complex biological drugs that need monitoring. The same pathways that heal can cause harm if pushed too far.’

Professor Richard Eastell, head of bone metabolism at the University of Sheffield, agrees. ‘Timing and dosage are everything,’ he says, giving the example of the peptide hormone teriparatide – used for osteoporosis – which build builds bone and ‘halves the risk of spine fractures in severe osteoporosis’.

If used incorrectly, ‘the same hormone that builds bone can, if given continuously, break it down’, he says.

Yet Haroon felt he had nowhere else to go for help.

‘I know it was experimental, but I did it properly under a doctor and it worked for me,’ he says. ‘I just wanted my life back.’