Rihanna is known to be one of the smelliest celebrities out there – so much so that Jennifer Lawrence, Cardi B and Ryan Seacrest have they all gush about it in interviews. But even if you shell out big bucks 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 heady mau de RiRi where people always go crazy.
You see, perfumes smell different to everyone—which explains why Chanel No. 5 your mom wore smells different when you spray it on your skin, and why you might be disappointed when you steal a spray from your bestie’s perfume — and there’s real science behind why.
Because perfumes smell different to everyone
To understand why certain scents present themselves differently to different people, it is first important to understand the basic chemistry of fragrance.
Most fragrance notes, i.e. fruits, flowers, woods, grass, etc., are organic aroma chemicals from nature. “From there, it’s a natural mixture, similar to sugar mixed with water, where different chemicals have different reactions,” says Krishna Kundu, chief perfumer at Antica Farmacista, explaining that what happens next is determined by molecular weights of compounds and how quickly selected notes express their aromas.
Top notes tend to be lighter (think: citrus) and provide the initial burst of fragrance that you immediately smell 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 come last — and only emerge when the top and middle notes evaporate.
“Citrus notes have a lower molecular weight, therefore [come out] first. Followed by floral, herbal and spicy notes, while vanilla, wood, musk, amber or leather scents have the largest molecules. [come out] last,” confirms Kundu.
While the science behind perfume notes is pretty simple, how they actually smell on your skin is a bit more complicated. Diet, body and environmental temperatures, and even perspiration play a role in how the same scent can differ between individuals.
The biggest factor here is the pH level of your skin. “PH levels refer to the acidity or alkalinity of a substance and can vary between individuals depending on diet and lifestyle,” says Kundu. While 7 on the pH scale is neutral, the National Library of Medicine states that “the skin’s natural surface pH averages 4.7,” making it slightly acidic.
With that in mind, your body chemistry—that is, 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 grow. Other factors such as genetics, diet and lifestyle habits can also affect how your body metabolizes certain scents.
External factors can also affect how a fragrance interacts with your body. “Excess body heat or hot weather will evaporate the top notes easily and so the perfume will smell mostly like the middle notes and dry down,” says Kundu. On the other hand, cool temperatures allow fragrances, especially the top notes, to last longer on the skin. And as for moisture, it’s actually a plus when it comes to fragrance. “Humidity will keep the fragrance on the skin longer than in dry weather,” adds Kundu. So the same perfume can smell different at different times of the year or even at different times during the day.
How to choose a perfume that suits you
According to Kundu, the first step to finding the perfect signature scent is knowing your skin’s natural pH, as some ingredients are more sensitive to pH changes than others. All you need to do this is a pH test strip, which you can get for under $10. From there, you can use this information to determine which scents will smell best (and last longest) on your individual skin.
“Perfumes containing citral, a compound found in citrus fruits and lemongrass, are more sensitive to acetalization reactions such as alkaline environments, leading to a change in the fragrance,” he explains “Additionally, some floral notes can become more intense and lively in an acidic environment. while others may be subdued or altered’.
These options can get you started, but remember: Choosing a signature fragrance is a highly personal endeavor, so feel free to spray and smell until you find what smells perfect to you.
If you have acidic skin (4-4.5)
“Choose perfumes with stronger base notes, as they tend to last longer,” says Kundu.
If you have neutral skin (4.5-6)
“Any scent will work great, and if you’re looking for more coverage, lean toward heavier scents with floral, woody, amber, or sweet notes,” says Kundu.
Ellis Brooklyn, MYTH Eau de Parfum — $108.00
Fragrance Family: Hot and spicy
Key Notes: Ambrette seeds, jasmine petals, musk
If you have alkaline skin (6+)
“Choose fragrances with lighter top notes, as they may show better on alkaline skin,” says Kundu.
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