AbstractObjectiveOverweight and obesity are characterized by excess adiposity and systemic, chronic, low‐grade inflammation, which is associated with several metabolic disorders. The aim of this study was to assess the feasibility and tolerability of β‐alanine supplementation and to explore the effects on cardiometabolic health and cardiovascular, hepatic, and renal function in adults with overweight and obesity.MethodsA total of 27 adults (44% female; mean [SD], age: 58 [10] years, BMI: 31.1 [2.9] kg/m2, hemoglobin A1c: 39.8 [4.3] mmol/mol) received β‐alanine (4.8 g/day) or a matched placebo for 3 months. Feasibility and tolerability outcomes included adherence, side effects, recruitment, attrition, and blinding, and exploratory outcomes included biochemical markers, blood pressures, and transthoracic echocardiography parameters. Data were analyzed using a Bayesian approach presented with 95% credible intervals (CrI).Resultsβ‐alanine was well tolerated and adhered to (adherence: placebo, 0.91 [95% CrI: 0.84–0.95]; β‐alanine, 0.92 [95% CrI: 0.85–0.95]), and side effects remained at or below baseline throughout. The probability that β‐alanine supplementation affected cardiometabolic, cardiovascular, or clinical biochemical outcomes was low.ConclusionsSustained‐release β‐alanine supplementation is well tolerated and adhered to in adults with overweight and obesity. Future research should consider more advanced metabolic conditions, which may benefit from longer duration supplementation.