ISSUE: Lab analysis has found Duro Extend Capsules for Men to contain Sulfoaidenafil, an analogue of Sildenafil, an FDA-approved drug used as treatment for male Erectile Dysfunction, making the product an unapproved drug. The analogue may interact with nitrates found in some prescription drugs (such as nitroglycerin) and may lower blood pressure to dangerous levels. Consumers with diabetes, high blood pressure, high cholesterol, or heart disease often take nitrates.