What do we know about ‘research only’ peptides? Q&A with expert Stuart Phillips

“Extraordinary claims that peptides can boost injury recovery, build muscle, and fight aging have helped these compounds explode in popularity — but what exactly are peptides and what does the evidence say about these claims? Peptides are branches of amino acids that can interact with the body in various ways. Insulin is a peptide with decades of research behind it. Semaglutide is another peptide medication, used to manage blood sugar (Ozempic) and weight (Wegovy). These examples are supported by extensive clinical data and regulatory approval from Health Canada. But not all peptides have regulatory approval as they lack the necessary human safety and efficacy data. Despite this, people are buying and injecting themselves with unapproved “research only” peptides, typically purchased from online retailers — a trend that has experts and health regulators concerned. We asked Stuart Phillips, professor in the Department of Kinesiology, about the rise of unapproved peptides: the risks, evidence, challenges, and proven alternatives. What are the risks of using unapproved peptides? The risks are substantial and multi-layered. Health Canada’s recent advisory also put it bluntly, “Think twice before injecting peptides bought online.” First, peptides sold on “research chemical” websites are not produced under the Good Manufacturing Practices (GMP) standards that are required for pharmaceutical companies, leaving end users with no reliable way to verify what it is they’re getting, let alone its purity, potency, and sterility. Second, there are biological risks from the peptides themselves. Take BPC-157, one of the most popular unapproved peptides. BPC-157 promotes angiogenesis — the growth of new blood vessels. While this sounds beneficial for healing, angiogenesis is directly implicated in tumour growth, cancer proliferation and inflammatory diseases. A third major risk is dosing. Unapproved peptides do not have established human dosing protocols, so users are essentially guessing at doses based on anecdotal reports. Even if a peptide seems “tolerated” in the short term, chronic or repeated use could produce side effects that take months or years to manifest. Are there any human studies of unapproved peptides? There is a striking and concerning lack of human evidence. Even with decades of animal research, the human clinical data for the most popular unapproved peptides is extraordinarily thin. Despite its popularity, a 2025 review found only three published human studies on the peptide BPC-157. Combined, these studies involved fewer than 30 human subjects and lacked control groups — none used a randomized, placebo-controlled design. The few studies to date on BPC-157 that report only positive effects are a warning sign — in a healthy and transparent research environment, we would expect to see some null or negative results. Do animal studies translate to humans? Roughly 90 per cent of drugs that show promise in animals ultimately fail in human trials. Animal data is a necessary first step, but it’s far from sufficient on its own to draw conclusions about a drug’s effectiveness and safety in humans. The history of medicine is littered with compounds that looked exceptional in animals and failed — or proved harmful — in people. What do you make of anecdotal reports found on social media? Anecdotal evidence on social media claiming dramatic benefits from peptides should be treated with significant skepticism for several reasons. For one, the placebo effect is real and powerful. When we buy into the belief that a product will give us the response we desire, we’ve primed ourselves to see those improvements. By praising peptides on social media, influencers become psychologically motivated to seek and emphasize information confirming that stance, dismissing anything that contradicts it. This creates self-reinforcing echo chambers that blur the lines between the effects of the peptide and the effects of expectation. Poor attribution skills should also make us skeptical. When people start taking peptides, they typically make several changes simultaneously: training differently, eating better, sleeping more, reducing stress, or using other supplements. Yet, they attribute any improvements to the peptide rather than to the constellation of changes they made and the natural healing that would have likely occurred anyway. Many influencers promoting peptides have financial relationships with suppliers, coaching services, or affiliate programs. Their testimonials are, effectively, advertisements. Social media algorithms also play a role here by amplifying positive testimonials, meaning those who had no response or experienced side effects using peptides are less likely to post about it. Instead of peptides, what do you recommend for optimizing recovery, healing, and performance? For musculoskeletal injuries, the best evidence supports structured rehabilitation and progressive loading through exercise programs designed by physiotherapy and sports medicine professionals. Ensuring adequate protein intake is necessary when it comes to recovery and tissue repair (1.6 grams per kilogram of body weight daily for active individuals). Optimizing sleep is also critical to growth hormone release, tissue repair, and immune function — and it’s one of the most cost-effective recovery interventions available. When faster or more effective healing is needed, evidence-based medical therapies include platelet-rich plasma (PRP) therapy, corticosteroid injections (with appropriate clinical guidance), approved anti-inflammatory medications, and in some cases, surgical intervention. Finally, chronic stress can impair wound healing and recovery. Mindfulness, cognitive behavioural approaches, and training load management can meaningfully support recovery. These alternatives may seem less exciting than a “cutting-edge” peptide injection, but they are grounded in extensive human evidence and carry well-understood risk profiles. What’s your final verdict on unapproved peptides? Injecting untested, unregulated peptides is, at best, a large waste of money and, at worst, a path to long-term side effects that we do not yet understand. The preclinical data are interesting enough to warrant proper human investigation, but it is not sufficient to justify self-experimentation. Until rigorous, randomized, placebo-controlled trials are conducted and published, the responsible position is to rely on proven, evidence-based approaches to recovery and healing, and to leave unapproved peptides where they belong for now: in the laboratory, not in your body. The post What do we know about ‘research only’ peptides? Q&A with expert Stuart Phillips appeared first on McMaster News .

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