‘I’m a Perfumer at a Luxury Fragrance Brand, and This Is Why Certain Scents Smell Different on Everyone’

It’s a known fact that Rihanna is one of the best-smelling celebrities out there—so much so that Jennifer Lawrence, Cardi B, and Ryan Seacrest have all gushed about it in interviews. But even if you splash out the big dollars for her rumored signature scent—Killian Paris’s Love, Don’t Be Shy—it doesn’t necessarily mean you’ll be walking around with the same intoxicating Eau de RiRi that people are always raving about.

You see, fragrances smell different on everyone—which explains why the Chanel No. 5 your mom used to wear takes on a different scent when you spritz it on your own skin, and why you may find yourself disappointed stealing a spray of your bestie’s perfume—and there’s actual science behind why.

Why scents smell different on everyone

To understand why certain scents present differently on different people, it’s first important to understand the basic chemistry of perfume.

Most fragrance notes, i.e. fruits, flowers, woods, grass, etc., are organic aromatic chemicals from nature. “From there, it’s a physical mixture, similar to sugar mixed in water, where different chemicals have different reactions,” says Krishna Kundu, Antica Farmacista’s chief Perfumer, explaining that what happens next is determined by the compounds’ molecular weights and how fast the chosen notes express their aromas.

Top notes tend to be lighter (think: citrus), and provide that initial burst of fragrance that you smell immediately when you apply your perfume. From there, you’ll get the middle notes (think: floral and spice), and the heavy base notes (think: vanilla) will be last—and only emerge when the top and middle notes evaporate.

“Citrus notes have lower molecular weight, so [come out] first. Floral, herbal, and spicy notes are next, and vanilla, woodsy, musky, amber, or leather scents have the biggest molecules, so they [come out] last,” confirms Kundu.

Though the science behind fragrance notes is fairly straightforward, how they actually smell on your skin is a bit more complicated. Diet, body and environmental temperatures, and even perspiration all play a role in how the same scent can vary between individuals.

The biggest factor here is the pH level of your skin. “The pH levels refer to the acidity or alkalinity of a substance and can vary among individuals depending on nutrition and lifestyle,” says Kundu. While 7 on the pH scale is neutral, the National Library of Medicine reports that “the natural skin surface pH is on average 4.7,” making it slightly acidic.

With that in mind, your body chemistry—meaning your skin’s pH and oil levels—can change the way the chemicals in fragrance formulations interact with your skin, which in turn changes the way they smell as they develop. Other factors like genetics, diet, and lifestyle habits can also influence how your body metabolizes certain scents.

External elements can also impact how a fragrance interacts with your body. “Too much body heat or hot weather will evaporate the top notes easily, and so the fragrance will primarily smell like the middle notes and dry down,” says Kundu. On the other hand, cold temperatures allow scents, particularly the top notes, to last longer on the skin. And as for humidity, it’s actually a positive when it comes to perfume. “Humidity will retain fragrance on skin longer than in dry weather,” Kundu adds. So the same perfume may smell different at different times of the year or even at different times over the course of a single day.

How to choose a scent that’s right for you

According to Kundu, the first step toward finding your perfect signature scent is knowing the natural pH of your skin, as certain ingredients are more sensitive to pH changes than others. All you need to do this is a pH testing strip, which you can snag for under $10. From there, you can use that information to determine which scents will smell best (and last longest) on your individual skin.

“Fragrances containing citral, a compound found in citrus and lemongrass, are more susceptible to acetalization reactions like alkaline environments, leading to a change in scent,” she explains “Additionally, some floral notes may become more pronounced and vibrant in an acidic environment, while others may be subdued or altered.”

These picks can help get you started, but remember: Choosing a signature scent is a highly personal endeavor, so feel free to spritz and sniff until you find the one that smells perfect on y-o-u.

If you’ve got acidic skin (4-4.5)

“Opt for fragrances with stronger base notes, as they tend to last longer,” says Kundu.

Sol de Janeiro, Brazilian Crush Cheirosa ’62 Bum Bum Hair & Body Fragrance Mist — $38.00

Scent Family: Warm and spicy 

Key Notes: Salted caramel, pistachio, vanilla

Phlur, Missing Person Eau de Parfum — $96.00

Scent Family: Warm and spicy

Key Notes: Skin musk, bergamot nectar, blonde wood

If you’ve got neutral skin (4.5-6)

“Any fragrance will work great, and if you are looking for more coverage, lean towards heavier scents with notes of florals, woodiness, amber, or sweet elements,” says Kundu.

Love Don't Be Shy, Killian Paris — $290.00

Scent family: Warm floral 

Key notes: Orange blossom, vanilla absolute, luscious marshmallow

Fragrance family: Warm and spicy

Key notes: Ambrette seeds, jasmine petals, musk

If you’ve got alkaline skin (6+)

“Choose fragrances with lighter top notes, as they may project better on alkaline skin,” says Kundu.

Antica Farmacista, Sun Kissed Eau de Parfum — $86.00

Scent family: Citrus-sweet

Notes: Neroli, honeysuckle, jasmine sambac, verbena, clementine, meyer lemon, green leaves, morning dew, and champaca

Glass Rose, MIX:BAR EDP Perfume — $20.00

Scent Family: Sweet floral 

Key Notes: Raspberry, bergamot, rose, peony, amber