What pharmacists need to know about the dangerous ‘stacking’ fitness trend

The weight loss medication market is exploding in parallel with a quieter underground market for performance enhancing drugs (PEDs). And the two are overlapping in a concerning fitness trend known as ‘stacking’, where users take both at the same time, driven by fitness influencers, pop culture, and easy access.

While one suppresses the appetite for fast-tracked weight loss, the other accelerates muscle gain using synthetic testosterone. Both require a pharmacist-issued prescription and should not be taken in combination with one another without medical guidance.

Recent research has found potential therapeutic effect of combination therapies with sex hormones and GLP-1 agonists in reducing body weight for people with hormone imbalances and medical conditions such as Type 2 Diabetes.

But there is growing anecdotal evidence that some men are stacking the two products without supervision or a medical need to.

The black market

A significant and dangerous black market has emerged for popular weight loss medication like Ozempic, Wegovy, and Mounjaro, driven by high demand, supply shortages and high costs. These counterfeit and unlicensed products are widely promoted and sold through social media platforms like TikTok, Instagram and Facebook, beauty salons and unverified online pharmacies and other e-commerce websites.

Related Article: Deprescribing: The pharmacists' role in stopping inappropriate medications

The same is true for PEDs including testosterone, methandrostenolone, nandrolone, stanozolol, and oxymetholone. Although they can be offered on prescription, the number of people who qualify is small and they are not intended as a fast-track way to see gains in the gym. Despite this, illegal steroid use can be found across local communities in gyms and other fitness environments.

A recent survey of 1,000 male gym-goers across the UK by Oxford Online Pharmacy found 61% have or may consider taking anabolic steroids, increasing to 75% of men aged 25-34-years-old. This is a public health concern which, if left unchecked, could become a big problem among younger generations.

Users combining the two has become a significant new risk, as gym-goers try to achieve fast fat loss and muscle gain at the same time without understanding the potentially dangerous and long-term side effects.

Understanding the practice of ‘stacking’ and the dangers

Historically, ‘stacking’ has been understood as part of the bulking-shredding concept in the fitness sector, where people cut body fat or build muscles in cycles and combine multiple PEDs to see greater and faster results. But the arrival of weight loss medications has added to this with anecdotal online reports suggesting it is now possible to bulk and shred at the same time by stacking weight loss medication and PEDs.

In isolation, there is a large body of scientific research that shows the potential side effects men could experience when taking PEDs which includes lower sperm count, permanent hair loss, mood swings and increased aggression.

Less is known about the long-term side effects of semaglutide which is a relatively new type of medication for weight loss. But experts have long warned about the dangers of extreme and rapid weight loss, with renewed concerns given the rising misuse of GLP-1 medications from unlicenced sources.

Losing weight too quickly can lead to side effects including pancreatitis, gallstones, loss of muscle mass, and weakened bones. To gain muscle at speed in parallel to losing fat can place extreme pressure on the musculoskeletal system and someone’s metabolic health.

Weight loss medications are intended to be taken weekly, in a controlled manner for the long term; not in a cyclical manner because they are not a ‘quick fix’. If you stop after an initial weight drop, you’ll likely see the weight come back. The same goes for anabolic steroids – as soon as testosterone levels drop down to natural levels, muscle mass will reduce. This could lead to users being trapped in a cycle of dependency, fearful of stopping and losing the results.

Anabolic steroids are considered a class C drug in the UK and many users are consuming them illegally, without a prescription. And those ‘stacking’ steroids with weight loss medication are most likely buying them on the black market too, as they would not meet the criteria to qualify for a prescription.

Related Article: Grey-market peptides: what pharmacists need to know

Taking two black market medications concurrently without medical oversight is incredibly dangerous. There is no guarantee what ingredients they contain, where the products have come from with no traceable supply chain and what the safe dosages would be – if any.

The role of practice and community pharmacies

While PEDs do not lead to an immediate ‘high’ like other illegal drugs, their physical results can be addictive for users who can find it difficult to stop.

For pharmacists, it is important to bear in mind that users of steroids for desired physical outcomes could mean they are more likely to be influenced by the growing media and public interest in weight loss medications and take both concurrently and consecutively. They may be taking both medications without a legal prescription which means neither will be recorded.

Recognising the signs of addictive behaviour behind PEDs and weight loss medication misuse is vital. Pharmacists should encourage people to disclose any illegal uses of either medication and understand the motivations and struggles of users that is driving the behaviour. With this information, users can be signposted and supported in seeking more specific professional help which may include addiction services.

With the right knowledge and understanding of the complex motivators and influences, pharmacists can be the front line of health advice for users of PEDs and weight loss medication, offering information on dosage, the dangers of sourcing unlicensed medication, monitoring and educating the public on the potential side effects and long-term health risks. This is information users do not get from black market sellers and online influencers.

Additionally, pharmacists can support people by providing education on safer injection techniques and sterile equipment, like needle exchange programmes.

Related Article: Risks and responsibilities raised by Pharmacy First

Expanding the pharmacist's role offers an effective path to reduce harm from PEDs and weight loss medication misuse. Medical guidance and supervision are essential to shift away from illicit markets and protect public health.