I began using Animal Flex recently after doing a comprehensive study of its formula. I especially concentrated on published research from the past year alone to get an understanding of how effective the ingredients in the product are.
For example, the studies show that glucosamine results in "significant reduction in the progression of joint structure changes compared with placebo as assessed by measuring radiologic joint space narrowing;" chondroitin sulfate increases cartilage volume; methylsulfonylmethane shows an "improvement in pain and physical function;" ginger root produces inflammatory mediators; turmeric "arrest[s] the degenerative changes in the bone and joints;" boswellia "prevents collagen degradation, and inhibits the production of pro-inflammatory mediators;" quercetin "protect[s] cartilage from stimulated aggrecan loss" (Aggrecan is the major core protein in the articular cartilage); bromelain has shown to ameliorate knee pain.
And that's not even the entire formula. So there's much to get excited about with Flex. People with existing joint and knee problems may very well feel the effects of this supplement after continued usage. But if you're athletic and don't currently have joint problems, taking this can assist in preventing inflammation and damage to cartilage.