Our objective was to improve the results of extracorporeal shock waves lithotripsy using hydroxycitric acid (HCA) like adjuvant therapy. Double blind randomized clinical trial using hydroxycitric acid versus placebo (ID NCT05525130). Multicenter study of adjuvant exposure to a food supplement with hydroxycitric acid (HCA), vs. placebo in patients with calcium oxalate and calcium phosphate lithiasis with indication for extracorporeal shock wave lithotripsy (ESWL). 81 patients were included in the study to compare the effect of HCA versus placebo. Stone fragmentation, the main efficacy variable. Other variables analyzed were stone size, Hounsfield Unit Stone and tolerability. Statistical study with SPSS, statistical significance p ≤ 0.05. Eighty-one patients were included, 40 in the intervention group with HCA and 41 in the control group with placebo. The average stone area was 174,36 mm 2 (SD: 32,83 mm 2 ) and the average hardness was 1128,11 (SD: 257,65), with no statistically significant differences between groups. Significant statistical differences were obtained in the analysis of the population by intention to treat and by protocol of the main variable, no fragmentation vs. fragmentation where 100% of the patients, who were given ESWL and took HCA, presented fragmentation while 17% of the patients with placebo did not reach fragmentation (p = 0.03). The adjuvant use of HCA in patients for whom ESWL has been indicated, facilitates stone fragmentation in all cases, which is not achieved in up to 17% of the patients who did not use HCA. We recommend the use of HCA in patients prior to shock wave treatment to improve their fragmentation in calcium stones.