Objectives: Studies have showed very low protein diet (VLPD) (0.3-0.4g/kg/day) with ketoanalogues can slow kidney progression in chronic kidney disease (CKD) patients compared to low protein diet (LPD) (0.6-0.8g/kg/day) alone. However, adherence to VLPD is challenging. In our hospital, CKD patients are advised LPD. It is unclear whether LPD + Ketoanalogues has additional benefit over LPD alone. Methods: This retrospective cohort study included CKD stage 4-5 patients on Ketosteril from 1/12/2020 to 30/9/2023 for a total duration >/= 6 months. All CKD patients were offered dietitian referral for LPD education upon new case referral to our renal clinic. Therefore Ketosteril (6 tablets/ day) is considered additional treatment to LPD. The eGFR slopes before and after taking Ketosteril were calculated. Paired t-test was used to compare the slope pre-and post-treatment. The subjects were separated into responders (decreased eGFR slope gradient) and non-responders (same or increased eGFR slope gradient). Factors for responders were analysed by independent sample t-test. Results: Fifteen patients were identified. Their baseline characteristics were showed in Table 1. The mean eGFR slope pre-treatment was -0.398 ± 0.466; the mean eGFR slope post-treatment was -0.122 ± 0.374 (p = 0.117) (Figure 1). There were 10 ‘responders’ to Ketosteril and 5 ‘non-responders’. Older age was a significant factor in predicting responders (68.4 ± 11.4 vs 53.7 ± 13.8, p = 0.046). Gender, causes of CKD, concomitant use of SGLT-2i and ACEI/ARB were not significantly associated with response in this study. Conclusions: The addition of Ketosteril for CKD 4-5 patients on LPD showed a numerical trend towards slowing CKD progression (although not statistically significant). Older age may favour response to Ketosteril. Further large-scale randomise control trial is needed to see whether adding ketoanalogues to LPD provides additional benefit.