Instruct: Classify the given Amazon review as either positive or negative.
Query: This stuff works fast.

I used this after I was diagnosed with early osteoarthritis in my left hand. I'm only 35, but my hand deteriorated so rapidly and severely that I had trouble bathing and getting dressed. I wanted to try glucosamine sulfate, and I chose Dona because results were proven in clinical trials.I am thrilled with this product. After only two weeks I had NO pain in my hand. It was amazing. Now I've been taking it for three weeks and I have nearly full mobility. This stuff is awesome and I plan to keep taking it. Highly recommended for arthritis.The only drawback is that it's expensive, especially since the directions suggest taking it every day for 3 years! I wish insurance would pay for this because it works like a charm.