Peptides: Friend or foe?

Longevity medicine has rapidly moved from the fringes of healthcare into mainstream medical discussion. Peptides, exosomes, amino acid therapies, and mitochondrial medicine are now dominating conversations in wellness, sports medicine, metabolic health, and anti-ageing research. Whether one agrees with the movement or not, modern medicine is evolving at an extraordinary pace. 

Over the past few months I have explored the world of peptides more closely, both scientifically and clinically. The experience has been eye-opening. It is becoming increasingly difficult to ignore the growing body of evidence, anecdotal experience, and patient demand surrounding these compounds. While scepticism in medicine is healthy and necessary, dismissing the entire field outright may ultimately prove short-sighted. 

The problem, however, is that the peptide industry currently sits in a complex and controversial space. The debate is often reduced to a simplistic argument surrounding US Food and Drug Administration (FDA) approval. Many peptides are indeed not FDA-approved. Yet medicine has always evolved ahead of regulation. Numerous supplements and therapies commonly used today, including creatine, vitamin D, dehydroepiandrosterone (DHEA), and even testosterone in certain settings, exist in similar regulatory grey zones. 

Unlike traditional pharmaceuticals, many peptides are naturally occurring amino acid chains already present within the human body. They function primarily as signalling molecules rather than as foreign chemical agents. This also explains why many are difficult to patent, limiting large-scale pharmaceutical investment and leaving much of the research and clinical use fragmented. 

The real concern at present is not necessarily the peptides themselves, but rather the uncontrolled and often dangerous grey market surrounding them. Social media has created an environment where wellness influencers, gym trainers, and unqualified individuals are prescribing substances with limited understanding of pharmacology, endocrinology, or long-term risk. 

This is where the true danger lies. 

Poorly manufactured peptides obtained through unofficial sources may contain contaminants, inaccurate dosing, or toxic compounds, including heavy metals and bacterial endotoxins. The consequences can range from severe nausea and headaches to anaphylaxis, systemic inflammatory reactions, and organ injury. Patients often assume that because something is marketed as natural or regenerative it must automatically be safe. That assumption is deeply flawed. 

If peptides are to have a legitimate future in medicine, they must be approached responsibly. Proper sourcing, quality control, and physician oversight are essential. 

Ironically, many people already use peptide-based medications without realising it. Insulin remains one of the most important peptide therapies ever developed. Oxytocin is another example. More recently, GLP 1 receptor agonists such as semaglutide and tirzepatide have fundamentally changed the management of obesity and metabolic disease. 

Semaglutide opened the door. Tirzepatide expanded on this by targeting both GLP 1 and GIP receptors, producing even more significant weight loss and metabolic improvement. These drugs are no longer simply obesity medications. Their effects on inflammation, cardiovascular disease, and addictive behaviour are becoming increasingly important. 

Retatrutide, currently one of the most promising emerging therapies, adds glucagon receptor activity to the equation, increasing energy expenditure and fat metabolism. Early trial data has demonstrated unprecedented weight-loss results approaching 30% in some patients. If these outcomes continue to hold true, obesity management may look completely different within the next decade. 

Beyond metabolic medicine, regenerative peptides such as BPC 157 and TB 500 have garnered enormous interest in sports medicine and injury recovery. BPC 157 appears to stimulate angiogenesis (blood vessel formation), collagen formation, and local tissue healing, while TB 500 may assist with broader cellular repair and recovery pathways. 

Yet caution remains critical. Any compound that potentially stimulates blood vessel formation or cellular growth must be approached carefully, particularly in patients with active malignancy or significant cancer risk factors. 

Mitochondrial peptides such as MOTS C and SS31 are also attracting attention for their potential role in energy production, recovery, and exercise performance through ATP optimisation. Similarly, growth-hormone secretagogues including Tesamorelin, CJC 1295, and Ipamorelin are increasingly utilised in longevity medicine, although they require careful patient selection and monitoring due to their metabolic and endocrine effects. 

At present several principles should remain non-negotiable. 

First, peptides should be obtained only through reputable and properly regulated compounding pharmacies with strict quality assurance standards. 

Second, patients should be extremely cautious of products marketed online at unusually low prices or labelled not for human consumption. 

Third, anyone considering peptide therapy requires proper medical evaluation, baseline blood work, and appropriate screening investigations before treatment begins. 

Last, peptides should never replace evidence-based conventional medicine or surgery where these remain clearly indicated. They are not miracle therapies. They are tools. In the correct setting and under appropriate supervision they may offer substantial benefit. Used irresponsibly, they carry very real risks. 

Medicine has always advanced through innovation, debate, and responsible scepticism. Peptides are unlikely to disappear from that conversation any time soon. 

And perhaps the final point worth reflecting on is: if these compounds truly had no physiological effect, organisations such as the World Anti-Doping Agency and professional sporting bodies would hardly have invested so much effort in banning them. 

• Dr Anton Meyberg is a specialist physician and pulmonologist in private practice, which is largely responsible for the Intensive Care Unit at Linksfield Clinic in Johannesburg.