What Does the Best Joint Supplement Do? This article discusses the benefits of the top three joint supplements, Physio Flex Pro and Peformance Lab Flex. Learn which one is right for you. If you are tired of the pain in your hips, hands, or knees, try a joint supplement. You'll be surprised by the difference! You can get joint relief without any side effects and a healthy lifestyle without pain! In this article we are exploring definitively what is the best joint supplement? Read on to learn more and answer the question answered by verified experts.