"Skin chemistry" in the context of perfumery refers to how an individual's unique body chemistry interacts with a fragrance when it's applied to the skin. The way a perfume smells on one person might be slightly or significantly different from how it smells on another person due to variations in natural oils, pH balance, skin texture and body heat.

Skin chemistry can cause the various notes of a perfume to develop differently. For example, the top notes might fade more quickly on someone with dry skin, allowing the middle and base notes to become dominant sooner. This could prompt floral notes to bloom earlier. On oily skin, the top notes might stay prominent for more time due to slower evaporation. Under these circumstances, a perfume with citrus notes might seem more vibrant and zesty.

Your skin chemistry and texture influences how long a perfume lasts on your skin. Oily skin tends to retain scents better, while dry skin might cause a fragrance to dissipate more quickly.

Body heat emitted from the skins surface activates and releases the different notes of a perfume - the molecules evaporate and become airborne, allowing the different layers of the scent (top, middle, and base notes) to unfold in time. The burn and projection rate of a perfume is affected by body temperature; this also means that perfume applied to warmer parts of the body like pulse points may develop differently than perfume applied to colder parts of the body.

Perfume ingredients can react with the other chemicals present on the skin, leading to the creation of new aroma compounds that were not present in the original fragrance composition. What you eat and drink, medications, and hormonal changes can alter the overall scent of your perfume.