Background: Activated charcoal has been widely used as an adsorbent for the management of drug intoxicated patients in the emergency department(ED). Although there are several commercial ready-mixed charcoal suspension preparations in the market, we are using custom-made suspension from hospital grade bulk charcoal power. We designed this study to compare the adsorptive capacity of the Acudose AquaR which is a commercial charcoal product, Fuller`s earth, and custom-made activated charcoal used in our ED. Methods: First, We performed modified USP methylene blue adsorption test which is a standard adsorption test for activated charcoal. Then, the drug adsorption test for Phenobarbital, acetaminophen, salicylate, and ammophylline was done. Graded amount of three adsorptives were added to the stock solutions of each drug. The adsorption test were performed as follows. The vials containing drugs and adsorptives were shaken for 30 minutes to ensure adsorption equilibrium, then the suspension was filtered through in-line filter. The filtrates were analyzed by ultraviolet spectroscopy to determine the residual drug concentrations Finally we examined and compared the surface area and the structures of activated charcoal and Fuller`s earth using scanning election microscopy. Results: In methylene blue adsorption test, the adsorption rate was 60.1% in Actidose AquaR and 59.0% in custom-made charcoal, and 70.2% in Fuller`s earth. For the phenobarbital, acetaminophen, and salicylate, the adsorption rate of Actidose AquaR and custom-made charcoal was greater than 90% with the ratio of adsorptives to drugs over 10.1 For aminophylline, two charcoal products showed excellent adsorption in 5:1 ratio. But Fuller`s earth showed poor adsorption in all ranges. Conclusion: Custom-made activated charcoal showed a comparable adsorption capacity to Actidose AquaR. Fuller`s earth showed a poor performance to be used as a substitute for activated charcoal in acute drug poisoning otherwise paraquat.