Not sure what it's supposed to do

Got a free sample of this through Chorus (and it came with a bunch of other samples).

I never got the chance to use this for a while since I don't really have joint problems. When I sprained my ankle, I tried to use it - but I felt like it made it feel worst !! I also tried it on my wrist and back after a long day at work, but couldn't really tell if it was doing anything. Overall definitely don't recommend