Fragrance experts share when it's time to toss that bottle. Over the years, I have received perfumes for every holiday that you can think of. However, my growing collection has made me wonder if perfume expires. Considering the price points of most fragrances, knowing whether or not to throw away a perfume you've had for a while can be a hard decision to make. So does perfume really expire? If so, how can you tell? Below, three of the country's top perfumers share everything they know about the lifespan of perfume and how to tell if your favorite scent has expired. Does perfume expire? Unfortunately, once a bottle of perfume has been opened, it will eventually expire. I know, this is sad news to hear, especially if you have a few open fragrances sitting in your bathroom cabinet right now. But the good news is, on average, an open fragrance can last about two years. "Spraying a perfume allows air into the bottle which oxidizes the fragrance over time," says Clement Gavarry, a senior perfumer at Firmenich, who has worked on creating many famous scents for brands such as Giorgio Armani, Calvin Klein, Tom Ford, and Chloé. "You'll notice a severely reduced signature of the fragrance itself, it will not smell sparkling." How long perfume lasts also depends on how it's stored. "If the fragrance is kept away from sunlight and high temperatures, it will last longer," Gavarry adds. "If the fragrance is kept in warm temperatures, the juice will turn faster, and it will only have a shelf-life of three to six months." How long can perfume last if unopened? This is a question that you may ask yourself every time you receive a new bottle of perfume, and frankly, with no expiration date on the bottle, it's pretty hard to tell. According to Givaudan perfumer Jacques Huclier, who has created fragrances for brands like Gucci, Thierry Mugler, and Hugo Boss, an unopened bottle of perfume can last several years depending on how it is stored. "I recently had the chance to evaluate a never-opened bottle of perfume from the 80s and it was like brand new," says Huclier. "There's no cardinal rule, each fragrance has a different lifespan." That said, it's definitely a good idea to finish one bottle before you start using another. Buying Perfume For Others Can Be Tricky — Here's How to Do It How do you know when perfume has expired? You can tell if a perfume has expired when the smell is slightly sour, especially as the top notes oxidize. This can have a slight metallic scent. "Oxygen within the air can alter some of the molecules present in a fragrance over time," says Huclier. "Generally, top notes like citrus, fruits, aromatics, green notes, and patchouli are most sensitive to oxidation. Another indication that perfume has expired is discoloration [of the juice]." According to Huclier, the good thing is that the shelf life of fragrances is extending longer than before, as many perfumers now use stabilizers and UV filters which make the molecules less sensitive to oxidation. The best way to check if a perfume has expired is to spray it on a piece of paper to see if you detect any off-note. This method also assures that you don't have the scent on you all day, especially if it has expired. "You can also check to see if the color or shade of the juice itself has changed," says Gavarry. "If it looks darker or has a yellow tint, it typically means the fragrance has oxidized." Finally, the trusted nose of a friend can also help you determine if it's time to throw the perfume out. Ask for someone's opinion. Can you extend the shelf life of perfume? Keep perfumes far from any heat source. Oxygen, light, and heat are the biggest enemies of perfume. "To extend the life of a perfume, it's best to store it in a cool dark place, away from heat and daylight, as UV light can harm the fragrance and breakdown its formula," says Gabriela Chelariu, a senior perfumer at Firmenich, who has created perfumes for brands such as Nest, Gwen Stefani, JLo, and Abercrombie & Fitch. "Keeping a fragrance in the refrigerator is actually the best climate and storage space." There are also some perfumes that tend to last longer than others. "In general, perfumes with spicy, wood, and vanilla notes have a tendency towards sustaining a longer shelf life than other perfumes in different olfactive categories," says Chelariu. "The nature of the natural ingredients within these formulas are more potent and structurally stable." Huclier adds that these rich base notes are less volatile and have a greater resistance to oxidation since they are less fragile. What happens if you use perfume after it's expired? Other than smelling a little off, not much. "It's not