What ingredient in perfume makes it last a long time?

The ingredient in perfume that make it last a long time is called a fixative. There are many different fixatives, but they all generally have a slow evaporation rate and a low molecular weight.

There are a few different types of fixatives. Natural fixatives are things like resinoids and animal products while synthetic fixatives are either chemicals of low volatility or those with low vapor pressures. It is worth noting that all of the natural fixatives must be chosen based on how the fixatives fragrance interacts with the top notes in the perfume. Some of the synthetic fixatives are odorless which gives them greater versatility.