In Chinese men with renal underexcretion-type gout, citrate supplementation (3.5 g twice daily) during the first 4 weeks of febuxostat therapy was associated with a higher proportion achieving serum urate < 360 μmol/L compared to those not receiving citrate supplementation, with a statistically significant difference at week 4 (P = 0.039), though no significant difference was observed at week 12.

Citrate increases the pH of urine, which makes uric acid dissolve more easily in the body's fluids. This prevents uric acid from forming sharp crystals that trigger inflammation and allows the kidneys to flush out more uric acid. At the same time, the higher pH directly blocks a key inflammation pathway in immune cells, reducing the release of signals that attract white blood cells to joints. Together, these effects lower uric acid levels faster in the first few weeks, even before the main drug starts fully working.