The expanding portfolio of effects attributed to GLP-1 receptor agonists – the class of drugs behind Ozempic, Wegovy and Mounjaro – continues to surprise researchers, moving far beyond glycaemic control and weight reduction. Viewed from London, a new study presented this week suggests the medications may significantly improve male fertility. After 24 weeks of treatment, men aged 18 to 65 showed notable increases in testosterone levels, sperm count, sperm volume and morphology, according to researchers at University Hospitals Coventry and Warwickshire. With roughly 15 per cent of couples in the United States experiencing difficulty conceiving, and male factors implicated in more than half of those cases, the finding opens a potential new therapeutic avenue for a condition long overshadowed by female-focused interventions.

At the same time, laboratories on both sides of the Atlantic are probing whether these drugs shield the brain from neurodegenerative decline. GLP-1 receptors are densely expressed in the hippocampus and hypothalamus, regions critical to memory and metabolic regulation. Emerging work published in Cell Metabolism indicates that semaglutide and tirzepatide may dampen neuroinflammation and help preserve the neurovascular unit, offering a plausible mechanism for slowing diseases such as Alzheimer’s and Parkinson’s. This line of inquiry runs parallel to renewed interest in curcumin, the active compound in turmeric, which has been used for centuries in traditional Asian medicine. Mexican researchers note that curcumin’s anti-inflammatory and antioxidant properties are now being rigorously tested for similar neuroprotective effects, positioning it as one of the most studied natural compounds in the prevention of cognitive decline.

Perhaps the most unexpected dimension comes from behavioural science. A study covered by The Independent found that people taking GLP-1 drugs exhibited weaker links between impulsivity, alcohol use and violent behaviour. Even when users drank or acted impulsively, the escalation to violence was significantly less likely, suggesting the medications may modulate the brain circuits underlying aggression. This adds a psychological layer to the drugs’ already complex metabolic profile, raising the prospect that they could one day be deployed in forensic or addiction settings.

Yet a cautionary note has been sounded from the United States. Research to be presented at the Endocrine Society’s annual meeting in Chicago reveals that adults with obesity who lose weight using GLP-1 agonists often markedly reduce their physical activity. The study’s lead author warns that because these drugs reduce both fat and lean muscle mass, abandoning exercise risks undermining long-term strength and metabolic health. The finding underscores a persistent tension in the weight-loss revolution: pharmacology can deliver rapid results, but without sustained lifestyle change, the full benefits may prove elusive.

Taken together, these studies paint a picture of a drug class whose pleiotropic effects are only beginning to be mapped. From the fertility clinics of the British Midlands to neurobiology labs in Brazil and behavioural research units in North America, GLP-1 agonists are forcing a rethink of the boundaries between metabolic, reproductive and mental health. Whether the promise of neuroprotection and reduced impulsivity will translate into approved indications remains uncertain, but the global research effort suggests these molecules may reshape far more than waistlines.