Cordyceps militaris is a medicinal fungus used in traditional medicine for treating fatigue, boosting immunity, and fighting cancer. This review explains how growing conditions—such as the type of grain or insect substrate used, light exposure, temperature, and nutrient balance—dramatically affect the production of beneficial compounds like cordycepin. The research shows that mixing grains with insect-based materials and using specific light wavelengths can significantly increase the potency of these medicinal fungi, making them more effective for health applications.