Each fragrance is composed, like a piece of music, by top, middle, and bottom notes. The top note is defined as the first impact or impression that a scent has-the note you smell immediately upon opening the bottle or applying it to your skin. Top notes last around 15 minutes, after which you can begin to detect the middle notes, which last up to an hour. 'It is from the middle notes that a fragrance is defined as being a certain type, such as citrus or floral. Middle notes become, in essence, the fragrance's identity. The bottom notes of a fragrance are what people are remarking on when they tell you how great you smell hours after you have applied your fragrance. In general, the fragrance you buy at the department store contains from 9 to 15 distinct notes.
Given the composition of a fragrance, it's understandable why many women make the mistake of purchasing one based on its first impression, or judging from the top notes only. This brings up one of the most important tips regarding fragrance: Try before you buy. Apply a fragrance where you normally would and see how the scent wears on you throughout the day. Rubbing your wrist against a fragrance sampler (the kind that comes in magazines) isn't a substitute for the real thing, since these samples can only recreate the chemical composition of a scent. You won't know how the actual fragrance reacts to your body chemistry until you wear the formula.
The other reason to try it firsthand is that even highly popular, instantly recognizable scents smell slightly different on different people. Your own body chemistry affects how a fragrance will smell. Oily skin, for example, tends to "hold" scents better and longer than dry skin. Heat and perspiration can also heighten the impact of a fragrance, one reason women are advised not to apply a scent before spending a day in the sun. Also, the high-fat, spicy diet traditional in our culture makes fragrances react more intensely with our body chemistry. These factors suggest that if you have oily skin, live in Texas, and eat lots of jalapenos and refried beans, you need to go easy with the atomizer, or people will smell you before they see you.
Your menstrual cycle affects how you may perceive a scent. In the first half of your cycle, your sense of smell is heightened, making you more aware of a fragrance's subtle notes. Pregnancy can also heighten your sense of smell-as anyone who has suffered from morning sickness can tell you. It's not uncommon for a pregnant woman to develop an intolerance to fragrances (and odors in general) that were pleasant to her when she was not pregnant.