I think of glucosamine as a wonder drug. My left shoulder became frozen - I couldn't lift my left arm more than 2 inches from the side of my body. Even when I didn't move, I was in horrific pain - sleep was out of the question.
After starting glucosamine, I felt pain relief within 2 days, could move the shoulder full-range within a week, and was completely pain-free within a month.
That was 6 years ago, and the problem has never returned.
Unfortunately, I now have Type 1 diabetes, and glucosamine sends my blood sugar readings sky-high. If you're not diabetic, try it.