Instruct: Classify Amazon reviews into positive or negative sentiment
Query: painfully disappointed

I have been taking 2 glucosamine pills a day for several years and decided to try Synflex after reading the reviews, so I stopped the pills and started taking the recommended dose of Synflex. After taking Synflex for a week, my joints became stiff and began to hurt a lot. I continued taking Synflex for a month, then stopped taking Synflex and resumed taking glucosamine pills again. After a few days back on the pills, my joints were less stiff and the pain lessened considerably. The weather and my activities were the same while I took Synflex and the pills, so they are not factors. Synflex did nothing to help my joint pain or inflammation.