Why Perfumes Contain Chemicals That Smell Like Poop

Here's a truth that might make you sniff your wrist differently: some of the world's most expensive perfumes contain the same chemicals that give human feces its distinctive odor. Indole and skatole—two organic compounds that contribute heavily to the smell of poop—are legitimate ingredients in the fragrance industry, used in everything from Chanel No. 5 to modern designer scents.

But before you swear off perfume forever, there's a fascinating twist to this story.

The Concentration Makes All the Difference

At high concentrations, indole smells like mothballs mixed with something intensely fecal. Skatole is even worse—its name literally derives from the Greek word skato, meaning "shit." In their pure, undiluted forms, these chemicals are exactly as unpleasant as you'd imagine.

But something magical happens when you dilute them to trace amounts. Suddenly, indole transforms into a rich, narcotic floral scent reminiscent of jasmine and orange blossoms. Skatole undergoes a similar metamorphosis, becoming warm, sweet, and intensely floral at extreme dilutions. This concentration-dependent personality shift is what makes them invaluable to perfumers.

Nature's Dirty Secret

Here's the kicker: these "fecal" compounds occur naturally in some of the most beloved flowers. Jasmine essence naturally contains about 2.5% pure indole—it's what gives the flower its rich, "animalic" quality that perfumers describe as sexy or narcotic. You'll also find traces of indole in ylang-ylang, neroli, bergamot, and petitgrain oils.

Skatole appears naturally in orange blossoms and jasmine as well. When you smell these flowers and find them intoxicatingly beautiful, you're partially responding to the same molecules that make feces smell offensive. Nature, it turns out, has a twisted sense of humor.

Used in Legendary Fragrances

Indole has been a secret weapon in classic perfumes for nearly a century. It's used in:

• Chanel No. 5
• Nina Ricci's L'Air du Temps
• Jean Patou's Joy
• Countless jasmine, tuberose, and orange blossom fragrances

Perfumers use these compounds in minuscule amounts—sometimes as little as 0.01-1% in special formulations. For context, the fragrance industry uses only about 5 grams of indole for every kilogram of more common ingredients like benzyl acetate. A little goes a long way.

The Animalic Signature

What indole and skatole provide is something called an "animalic" note—a quality that adds depth, warmth, and a slightly carnal sensuality to perfumes. This is the same reason historical perfumes used actual animal products like musk, civet, and ambergris. These animalic elements make fragrances smell more human, more alive, and paradoxically more attractive.

When a perfumer talks about a scent having "radiance" or "diffusion," they're often describing what trace amounts of indole bring to a composition. It's the difference between a flat, one-dimensional floral and a complex, captivating scent that evolves on your skin.

The uncomfortable truth? The boundary between disgusting and delightful is sometimes just a matter of dilution. The next time you catch a whiff of expensive perfume, remember: you might be enjoying the sophisticated cousin of the compounds that make bathrooms smell bad. And somehow, that makes the whole thing even more fascinating.