Source: https://www.amazon.com/Natures-Way-Activated-Charcoal-Capsules/dp/B0006LCQ4Q/ref=pd_bxgy_200_2?_encoding=UTF8&pd_rd_i=B0006LCQ4Q&pd_rd_r=3GA9KAK0NS1ZNAWV4NG5&pd_rd_w=mfX8j&pd_rd_wg=ZrY8L&psc=1&refRID=3GA9KAK0NS1ZNAWV4NG5