Quercetin, a widely distributed plant-based dietary flavonoid, has demonstrated promising metabolic health benefits; however, its limited bioavailability remains a major barrier to its practical nutritional application (1). Therefore, this work addressed two questions: whether a high-bioavailability quercetin formulation provides metabolic benefits in humans, and whether a food-based delivery strategy can enhance quercetin bioavailability. A randomised, double-blinded, placebo-controlled crossover trial was conducted in 33 healthy participants (63.6% female; median age 40 [20-68] years; mean BMI 29 [25-40] kg/m²). Participants received an isoquercitrin-γ-cyclodextrin formulation (IQC-γ-CD; 26.9 times Cmax higher than quercetin aglycone; 65 mg quercetin equivalents/day; isoquercitrin: a highly bioavailable glucoside derivative of quercetin) or placebo for 6 weeks each in random order, separated by a 6-week washout, while consuming a high-purine/fructose (HPF) diet throughout the trial. Plasma and serum metabolic biomarkers were assessed to investigate the metabolic effects of high-bioavailability quercetin. Plasma uric acid increased by 7.35% during the HPF/placebo arm (95% CI: 7.8 to 29.6 µmol/L; p = 0.001), but this increase was suppressed by HPF/isoquercitrin treatment (95% CI: -9.9 to 23.1 µmol/L; p > 0.05; difference between treatments 95% CI: 7.5 to 41.1 µmol/L; p < 0.01). Similarly, fasting plasma insulin levels increased 8.5% during the HPF/placebo arm (p < 0.05, 95% CI: 7.85, 61.78), but isoquercitrin attenuated the changes (p > 0.05, 95% CI: -14.34, 63.72), with a difference between treatments (p < 0.05, 95% CI: 0.67, 78.65). Serum leptin receptor level increased during HPF/isoquercitrin treatment by 7.18 ng/mL (p < 0.01, 95% CI: 2.97, 13.03), while adiponectin decreased in the HPF/placebo treatments (p < 0.05, 95% CI: 0.07, 1.70), but remained stable with isoquercitrin (p > 0.05, 95% CI: -1.38, 0.02). In summary, these findings indicated that isoquercitrin modulates metabolic responses during consumption of an HPF diet. The lack of effects on other cardiometabolic markers likely reflects the absence of HPF diet-induced impairment in these parameters, leaving limited scope for improvement with isoquercitrin (all p > 0.05). Since the above was a formulation in a capsule, we attempted to create a food that contained enhanced bioavailability quercetin. Building on our previous systematic literature review, which identified dietary lipids and fibre as potential enhancers of isoquercitrin absorption (2), we developed an isoquercitrin-enriched breakfast cracker as a food-based delivery system and evaluated its ability to enhance bioavailability compared with capsule supplementation in a randomised, double-blind, crossover trial involving 12 healthy participants. The functional food intervention has been completed, and urinary quercetin metabolite analyses are ongoing. Together, these works establish a translational framework linking improved quercetin bioavailability with promising metabolic health outcomes related to uric acid metabolism and provide a rationale for developing quercetin-enriched functional foods as practical dietary delivery systems.