aromatic mystery

Why Vitamin C Serums Smell Like Hot Dogs: An Investigation

Photo: Jeffrey Coolidge/Getty Images

Recently, I decided to rotate a vitamin C product into my skin-care routine. I wanted to spice things up, and ascorbic acid (another name for vitamin C), I thought, would be just the thing: it supposedly has brightening abilities, boosts sun-protection, and combats free radicals from pollution. What could go wrong?

I decided on the Drunk Elephant C-Firma Day Serum because I found a cheap miniature size at Sephora. I expected it to smell pleasant, sweet, and citrusy, but I was in for a surprise when I cracked it open one morning. Upon massaging the product into my face, a metallic scent overwhelmed my poor, unsuspecting nostrils. It almost smelled like pennies, but with a little more depth. It was more … meaty. And it definitely reminded me of something, but I couldn’t put my finger on what.

Off-put by this experience, I decided to try a handful of other vitamin C products in the hope of finding one with a tolerable scent. No dice — the tinny, burnt smell lingered no matter what.

I started scouring the internet for information on why exactly these products smelled so unpleasant — was it a certain ingredient? Or maybe the way they reacted with compounds like oxygen in the air? While deep-diving into Reddit forums, Sephora reviews and Twitter threads, I discovered many other skin care-enthusiasts had been sucked into this aromatic predicament, too. And they all said vitamin C products smell like one thing: hot dogs.

Even an Into the Gloss blogger noticed the scent — and that Sephora reviewers said Drunk Elephant’s serum smells like hot dog water or stale bacon — and Refinery29 also noted the products’ inescapable smell. I smelled my products again, and they were spot on — definitely hot doggy. It’s kind of like the lingering, acidic scent of slightly burnt breakfast sausage in the morning, or the metallic aroma of leftover water from boiled hot dogs your mom used to leave on the stove.

In an effort to find a product that wouldn’t make me smell like a tasty ballpark snack, I decided to get to the bottom of this puzzling aroma. If I could pinpoint the one responsible molecule or ingredient, I could find products without that ingredient that presumably wouldn’t stink. Then, I could reap the powerful benefits of vitamin C without any of the fragrant repercussions.

My first thought for the ingredient at large was ascorbic acid itself — it is, after all, the common denominator in every hot dog–scented product. So, first, I looked to see if any hot dog ingredients overlapped with any ingredients in my serums. Ascorbic acid, in fact, is an ingredient in many hot dogs, according to the National Hot Dog and Sausage Council.

Eager to confirm my theory, I dialed up some dermatologists to learn more about the molecule’s benefits and potential stinkiness.

“Vitamin C is a great ingredient,” said Patricia Farris, an associate professor of dermatology at the Tulane University School of Medicine. “Enzymes that make collagen require vitamin C, so it’s a collagen booster. It also inhibits the enzyme that makes melanin in your skin, so you get a lightening effect.”

Rajani Katta, a dermatologist and professor at the University of Texas’ McGovern Medical School, echoed Farris. “We’ve known how important vitamin C is for hundreds of years,” Katta told the Cut. “In the current day, we see smokers or people who subsist on processed foods and don’t get enough vitamin C having weaker collagen and saggier skin. Way back when, scurvy was the extreme version of this.”

Farris also said vitamin C is a powerful antioxidant. Antioxidants clean up the lingering free radicals in your body — free radicals are unstable molecules that can damage cells, DNA, and collagen. Such damage accelerates the aging process in human skin, which we can see visibly with things like sunspots and wrinkles. (Free radicals, in addition to the sun’s UV rays, play a role in skin cancer, too.) If you live in a city like I do, free radicals from smog and cigarette smoke can be a big concern when trying to uphold a plump, glowy visage.

So ramping up topical antioxidants is a way to keep your skin looking youthful and healthy. Farris advises wearing a vitamin C serum every day underneath sunscreen. “It’s not about how old you are or where you live,” she said. “This is standard not just for beauty, but also for fighting skin cancer.”

But … the smell. I asked Farris if her patients ever complained about the smell.

“All the time!” she said.

With bated breath, I asked her: “What is causing it? Is it the ascorbic acid itself?”

She hit me with a dagger. It couldn’t be. “Ascorbic acid is scentless.”

Farris said she didn’t know why vitamin C serums smell like hot dogs, but requested I let her know if I found out. Ugh. Back to square one. If ascorbic acid wasn’t causing the scent, what was?

I reached out to a few skin-care companies, and Skinceuticals — whose product, C E Ferulic, is largely regarded as the gold standard of vitamin C skin-care products, and probably smells the hot doggiest of all — got back to me.

“The ‘hot dog’ scent cannot technically be pinpointed since it is a combination of the raw ingredients,” Deepa Sunkari, the medical director of Skinceuticals, told the Cut in an email. “Many attribute it to the addition [of] ferulic acid.” (Ferulic acid is often formulated into vitamin C products because, as studies have shown, it improves sun-protection.)

This answer did not satisfy me. Many products that do not have ferulic acid still give off essence of hot dog when you put them on. Could it be that when ascorbic acid comes into contact with the air and oxidizes — a chemical reaction ascorbic acid is very prone to — a tinny meat smell is synthesized?

I asked the derms. They said they didn’t know. They said that probably no one knows.

At that point I was getting desperate. How on Earth could I ever experience the brightening, pollution-fighting effects I so desired if I had to smell like a Sunday ham every day of the week?

Grasping at straws, I contacted Johan Lundström, a biologist and psychologist at the Karolinska Institute in Sweden who studies odor — he looks at why we smell what we smell.

Lundström told me that the human sense of smell is muddy, pliable, and extremely imprecise compared to our other senses. For example, Lundström said, a cup of coffee has 150 to 200 different scent compounds, but those compounds are in many other products and don’t necessarily smell anything like coffee to us. Conversely, one compound that isn’t in coffee at all can smell almost exactly like coffee.

“Just because you find one chemical in one odor doesn’t mean you can find that chemical in another odor,” he said. “You could be picking up on things that are communal in hot dogs and face cream, but odor is a psychological concept.”

Oh God, I thought to myself. I’ll never get to the bottom of this.

He continued to tell me, as I sat at my desk in a cold, desperate sweat, that humans — at least those of us that grew up in Western culture — are very impressionable and vulnerable to suggestion when it comes to olfaction. This is due to the way our brains process odors, Lundström said, and also because we don’t learn to identify scents the same way we do with shapes, colors, or sounds as children.

A classic example of how impressionable we are, according to Lundström, can be achieved by tricking your friends with some shredded parmesan cheese in a jar. Blindfold them, and ask them to smell it. If you tell them it’s vomit, they’ll say it smells absolutely disgusting. But tell them the jar contains delicious parmesan cheese, and they’ll rave about how good it smells.

So that means if someone tells you your serum smells like hot dogs, you could cling to that and truly believe that it does. This realization hit me like a bolt of lightning — I didn’t realize my serums smelled like hot dogs until I saw that others thought so on the internet. When I asked my friends who were unaware of the association what they thought my Skinceuticals C E Ferulic smelled like, they all paused and thought for a while, unsure. When I asked them if it smelled like hot dogs, they locked eyes with me immediately, and said, “Yes!!!”

So could all of the blogs and posts and tweets be spreading the hot-dog rumor, manipulating the olfactory sense of vitamin C-users?

“It’s possible,” Lundström said.

I believe it. It could totally be the case that vitamin C serums don’t smell like hot dogs at all. We just think they do.

Still, even if I am under some kind of psychological spell, it is really difficult to un-brainwash myself. And with the hot dog-scented ingredient(s) still unidentified — if they exist at all — I’m not optimistic about finding a vitamin C product without its signature scent that’s not muddled with artificial or added fragrances that might irritate my skin.

So the mystery remains, and perhaps that’s okay. For all of the scientifically backed benefits of vitamin C, I guess it had to have a flaw somewhere — nobody’s perfect. I’ll still wear it under my sunscreen and deal with the fragrant consequences.

Why Vitamin C Serums Smell Like Hot Dogs: An Investigation