LONDON — Regulators and sports medicine specialists are raising urgent warnings about an expanding online market for performance-enhancing substances that are being sold without prescription and frequently without accurate labeling, exposing amateur athletes and recreational fitness enthusiasts to serious and in some cases life-threatening health risks.
A review published this week by a sports medicine research group found that dozens of compounds — including selective androgen receptor modulators, or SARMs, peptide hormones, and novel beta-2 agonists — are readily available through social media storefronts, direct-messaging platforms, and lightly regulated e-commerce sites operating across multiple jurisdictions. The substances are frequently marketed as dietary supplements or research chemicals as a means of evading pharmaceutical regulations, yet many carry pharmacological profiles comparable to controlled drugs and can cause significant physiological harm when used without medical supervision.
SARMs, which are designed to mimic the muscle-building effects of anabolic steroids while theoretically producing fewer androgenic side effects, have not been approved for human use by regulatory authorities in the United Kingdom, the United States, or the European Union. Clinical trials exploring their therapeutic potential in conditions such as muscle-wasting disease and osteoporosis have been discontinued or remain incomplete, leaving the long-term safety profile largely unknown. Despite that regulatory status, researchers found that SARMs were among the most commonly advertised substances on the platforms they monitored over a six-month observation period, with some storefronts listing dozens of variants at prices accessible to a broad consumer base.
Health professionals have documented cases of acute liver toxicity, hormonal suppression requiring medical intervention, cardiovascular complications including elevated blood pressure and adverse changes in cholesterol profiles, and psychological disturbances — including heightened aggression and depressive episodes — among individuals who used such products without medical oversight. Because the substances are often mislabeled or contain undisclosed active ingredients, users may be unaware of what they are actually consuming or at what effective dosage.
Dr. Samuel Adekunle, a consultant in sports and exercise medicine, said the problem is compounded by a cultural environment within some fitness communities that normalizes performance enhancement and frames side effects as an acceptable trade-off for physical gains. "We are seeing a generation of young men in particular who have been exposed to persistent messaging that makes these substances appear routine," Dr. Adekunle said. "The reality is that we do not have adequate long-term human safety data, and the short-term risks we can already document are serious and are presenting in clinical settings with increasing frequency."
Regulatory bodies in multiple countries have taken enforcement action against specific suppliers, but experts describe the market as highly adaptive, with vendors rapidly relocating their operations to new domains, encrypted messaging applications, or overseas hosting environments whenever one channel is disrupted. The cross-border nature of digital commerce makes comprehensive enforcement exceptionally difficult without coordinated international cooperation, and the pace at which new synthetic compounds are developed frequently outstrips regulators' ability to schedule substances under existing controlled drug frameworks.
Anti-doping authorities have noted that the proliferation of these substances poses risks not only to health but also to the integrity of competitive sport at amateur and semi-professional levels, where testing infrastructure is considerably less robust than at elite tiers. Athletes who consume contaminated or mislabeled supplements may inadvertently ingest banned substances and face disciplinary sanctions even when their intent was not to cheat.
Consumer advocacy organizations are calling for tighter due-diligence requirements on e-commerce platforms to verify the regulatory status of substances listed for sale through their marketplaces, and for greater investment in targeted public awareness campaigns aimed at recreational athletes and gym communities. Health authorities said they are closely monitoring the trend and urged anyone considering the use of performance-enhancing products to consult a qualified healthcare professional before proceeding, emphasizing that many of the claimed benefits are unsubstantiated by peer-reviewed evidence while the documented risks are real and in some cases irreversible.
Sports scientists studying the phenomenon said the widespread availability of these products also reflects a broader cultural shift in the way physical performance and appearance are discussed and valued in online fitness communities, where algorithms on major platforms can rapidly amplify content that promotes supplement use to receptive audiences. Researchers who have tracked such communities over time say that intervention strategies focused solely on legal enforcement are unlikely to be sufficient, and that education campaigns embedded within those communities — including content from credible athletic figures willing to speak openly about the risks — may be a necessary complement to regulatory approaches if the trend is to be meaningfully reversed rather than simply displaced to new channels.