They do go bad. Buy a new bottle and smell it against last years. There will probably be a big difference in strength. I actually open the bottle and smell it before I buy it and have been doing it for years, Also just like batteries, buy it in a place that moves it fast. Costco for batteries and Outdoor Emporium for scents. I bought some shrimp scent years ago in a little store on the way to Westport. After I bought it I smelled it on the water and it was not strong at all. It was smelly jelly and the bottom of the bottle was stained orange. It was lighter colored at the top of the oil. I talked ot one of the guys at the Sportsman show that works for Pro Cure and he said that the scents really start breaking down at 80 degrees and warmer. I usually leave smelly jelly paste in the back of my boat seat and when I pull it out months it is faded and not to potent. The sun does hit it there. I change it out often. I have a small 6 pack cooler with all of my scents that I either put it in the fridge or in the cuddy of the boat to keep it cool. It seems to last that way.