An extract from seeds of Chenopodium quinoa Willd. (quinoa), termed hydrolyzed quinoa (HQ), was obtained by enzymatic hydrolysis from seeds of the quinoa variety BRS-Piabiru. Analysis of the physical and chemical properties of quinoa and HQ showed that the hydrolyzed extract is rich in essential amino acids, particularly those with branched chains (leucine, isoleucine, and valine). In addition, we evaluated the biological effects of HQ, particularly the toxicological potential. For this purpose, male Wistar rats were assigned randomly to four groups: (1) sedentary supplemented group, which received HQ (2,000 mg/kg); (2) sedentary control group, non-supplemented; (3) exercised supplemented group (i.e., rats subjected to aerobic physical exercise that received HQ [2,000 mg/kg]); and (4) exercised control group (i.e., rats subjected to aerobic physical exercise, non-supplemented). After 30 days, all groups were analyzed for levels of serum glucose, cholesterol, triacylglycerol, total protein, albumin, uric acid, and urea and activities of the enzymes alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase. Body weight gain, dietary intake, and lipid deposition were also analyzed. The results showed no hepatic and renal toxicity of HQ. Moreover, decreased food intake, body weight, fat deposition, and blood triacylglycerol level were observed in the supplemented groups (sedentary and exercised supplemented groups). These results suggest a potential use of HQ in human nutrition.