Hyperphosphatemia management is initially based on restricting dietary phosphorus intake. Hyperphosphatemia is almost always seen in patients on dialysis and may contribute to progressive vascular calcification. Considering that activated charcoal is generally well-tolerated and may have a favorable side effect profile compared to conventional phosphate binders, it presents a promising alternative. Until now, no clinical trial has primarily investigated the effect of activated charcoal on hyperphosphatemia in dialysis patients.

Inclusion Criteria:

1. Adult aged ≥18 years with ESRD.
2. Patients who had been on stable maintenance hemodialysis (3 times weekly) for at least 6 months.
3. Patients receiving phosphate binders according to standard protocols established by kidney disease: Improving Global Outcomes (KDIGO).

Exclusion Criteria:

1. Severely malnourished (as diagnosed by the department's dietitian).
2. Treated with overnight dialysis.
3. Primary hyperparathyroidism or persistent serum levels of intact parathyroid hormone greater than 800 pg/mL.