I’ve noticed guys at the gym and on social media talking about peptides as the next big thing for building muscle, losing body fat, and even slowing down ageing. What exactly are peptides, do any of these claims stack up, and what are the risks of taking them?
I’d be very cautious about taking health advice from social media, particularly when it involves injecting substances you’ve bought online.
Peptides are short chains of amino acids that occur naturally in our bodies and are involved in things like growth, metabolism and appetite. There are also well-established peptide-based medicines that have been carefully studied and approved for specific medical conditions. GLP-1 receptor agonists used to treat type 2 diabetes and obesity are one example.
But that’s very different from the growing number of so-called “peptides” being promoted online for building muscle, burning fat or slowing ageing.
For many of these products, there simply isn’t good-quality evidence from human studies showing that they work as advertised, and we often don’t know what the long-term risks are. If you’re buying them online, there’s another problem: you may not know exactly what you’re getting. The product may be the wrong strength, contain something different from what is on the label, be contaminated or not be sterile.
Injecting a contaminated or non-sterile product can cause serious infections, and depending on the peptide, there may also be effects on hormones, blood sugar and other body systems.
Some peptide medicines are genuinely useful treatments when prescribed for the right reason, but that doesn’t mean the unapproved products being promoted at the gym or on social media are safe or effective.
If your goals are building muscle, losing body fat or recovering better, talk to your doctor, a registered dietitian or an appropriately qualified exercise professional.
