GLP-1 Drugs · 8 cited studies

Research on GLP-1 Drugs

GLP-1 receptor agonists (semaglutide, tirzepatide) are the most effective pharmacotherapy for weight loss in trial history — STEP 1 produced 14.9% mean weight loss at 68 weeks, and SURMOUNT-1 produced 20.9%. The cardiovascular benefit (SELECT 2023) is real: 20% reduction in major adverse events in obese non-diabetic adults. But the trial literature also names two underappreciated problems: (1) ~25–40% of total weight lost is lean mass — a sarcopenia and bone-density risk demanding active countermeasures (Linge 2024, Jensen 2024); (2) discontinuation produces rapid regain (STEP 1 extension: two-thirds of weight back at one year). The honest position from the literature: these drugs work, work better with serious lifestyle scaffolding (resistance training + 1.6–2.0 g/kg protein + UPF reduction), and probably need to be lifelong for many users — or replaced by sustained behaviour at the off-ramp. Below: the pivotal trials and the muscle/bone literature.