When sourcing mushroom extracts, the primary indicator of potency is the Beta-glucan content. Unlike total polysaccharides, which can be inflated by starch or grain fillers, Beta-glucans are the specific bioactive compounds responsible for health benefits. Ensure the supplier provides a Certificate of Analysis (COA) specifying a Beta-glucan level of at least 20-30% for species like Reishi, Lion's Mane, or Cordyceps. Additionally, for Reishi, verify the Triterpene levels to ensure functional efficacy.