Ganoderma lucidum and Cordyceps militaris are two major medicinal mushrooms with long-term usage in traditional and modern medicine. Along with the development of the research and cultivation of medicinal mushrooms, numerous commercial products, such as functional and supplemented foods, have been produced. Among them, the CORDY-X mushroom extract is the product that has the main ingredients of C. militaris and G. lucidum mushroom extracts. The Institute of Applied Technology, Thu Dau Mot University researched and transferred this product. In this study, we evaluated the product’s quality standards, quantified major bioactive compounds, adenosine, and cordycepin, by the UPLC method, determined the antioxidant activity against DPPH free radicals, and assessed cytotoxicity on human fibroblast cells and toxicity on Artemia franciscana shrimp. The results showed that the product meets quality standards. The adenosine and cordycepin contents were 0.95 mg/g and 0.26 mg/g, respectively. The product scavenged 27% of DPPH free radicals at a 250 µg/mL concentration. The product is not toxic to human fibroblasts or to Artemia franciscana at concentrations of 500 µg/mL and 1000 µg/mL. The findings clarify some pharmaceutical ingredients, antioxidant activity, and the safety level of pharmaceutical herbal products.