My dog, Billie (see profile pic) was diagnosed with arthritis in her left hip at about 9 years old. The vet said it's not related to hip dysplasia, just plain arthritis. That's when I started giving her glucosamine chondroitin. She gets a pill every day.
That was about 2 and a half years ago. I think it helps her quite a bit. She is occasionally a little stiff when she gets up, but for the most part she's her healthy playful self. Before she was on it, there were a couple of flare ups when she would be unable to go up the stairs at all. Since the glucosamine chondroitin, it has never gotten that bad.
Billie is about 40 lbs., mixed breed (you tell me what you think she is--I've heard all kinds of guesses). Now almost 12 years old. Just yesterday she was running all over the damn place, up and down the stairs, with her crazy noise-making toys.