Mycotoxins are natural contaminants of livestock feeds that can impair production efficiency. Specialized feed additives known as mycotoxin adsorbents may reduce absorption of mycotoxins in animals. Many additives are thought to use nonspecific binding to sequester mycotoxins in the lumen of the gastrointestinal tract, but there is a lack of in vivo mechanistic evidence. The current research sought to quantify the adsorptive capabilities of a yeast cell wall-derived mycotoxin adsorbent and confirm whether its mode of action is by adsorption of the mycotoxin. Using radioactive aflatoxin B2, it was found that there was a significant reduction in urine radioactivity when the adsorbent was present and observed over time. No other significant effects of diet were noticed in the liver, kidneys or muscle. Without feces and tissue data in agreement with urine, it was inconclusive whether this adsorbent reduced absorption of aflatoxin in rats.