My totally unscientific study. I'm 45, almost 46 and getting a bit creaky, but insist on continuing my high impact activities, such as Zumba, running, Turbo Fire... Without it, I have annoying aches - not bad enough to be pain, but enough to keep some of my high impact from being attainable. I started taking it, just to see and 3 weeks later, my knees are more stable, my ankles don't bother me (I tend to suffer from Achilles tendon) and feet are happy. Seriously, I love the stuff. I feel like I lost 10 years off my age. So, to me it's worth it. But like every thing else Your Mileage May Vary.