A popular beauty myth is that storing your nail polish in the refrigerator will allow it to keep longer and prevent discoloration. In fact, putting nail polish in the refrigerator can actually cause it to thicken and separate faster. There are a few methods you can use when storing your nail polish that will keep it from becoming thick and separating. When nail polish has separated, it will have a layer of oil on the top. If you do end up with separated nail polish, there is a way to fix it.
Store your nail polish in a cool, dry place. A medicine cabinet or makeup box is an excellent location. Placing your nail polish on a surface where heat or sunlight can reach it will cause separation.
Store your bottles of nail polish upright. This may seem obvious, but if a nail polish bottle falls over, set it back up right away. It will keep the ingredients properly layered and prevent separation.
Invest in quality nail polish. Cheap nail polish is more likely to separate and is harder to fix. More expensive nail polish will be a better investment in the long run, and it stores well.
Open the nail polish and check that it has separated. If the nail polish is stringy, it can't be salvaged and needs to be thrown away.
Add two to three drops of nail polish thinner to the nail polish, and place the lid back on.
Roll the bottle of nail polish between your hands to pick the thinner. When you open the bottle, the polish should have mixed back together. If not, add another drop or two of thinner and repeat this step.