These are the chemicals that give teens pungent body odor

Carboxylic acids and steroids contribute fruity, musty and sandalwood-like scents

Close-up of a young woman's sweat-stained underarm area.

Researchers found two smelly steroids and a mix of pleasant and acrid carboxylic acids in samples of teenage body odor.

Olga Ihnatsyeva/Getty Images Plus

Puberty changes just about everything. Bodies get taller, muscles get stronger — and often, body odor becomes more pungent. Now, scientists have identified some of the compounds that give teenagers their natural aroma.

Unlike that of infants and toddlers, teenage body odor has two smelly steroids and higher levels of carboxylic acids, researchers report March 21 in Communications Chemistry. Those chemicals form when bacteria break down armpit sweat and sebum, the oily secretions that keep our skin moist, and may contribute to the noticeable changes in BO throughout puberty.

“Body odor changes through development,” says chemist Helene Loos of Friedrich-Alexander-Universität Erlangen-Nürnberg in Germany. “There is a really great diversity of different odor compounds that are present in body odors.”

Loos and colleagues collected body odor samples from 18 teens age 14 to 18 and 18 young children age 0 to 3 who had slept with cotton pads under their arms for a night. Separating the body odor into individual components revealed that young children and teens have over 40 compounds in common.

While some classes of chemicals showed no difference between age groups, the scents of carboxylic acids were more prevalent in teens. These compounds were a mix of pleasant scents, described by a panel trained to evaluate olfactory cues as fruity, soapy or grassy, and less-appealing ones that smelled cheesy, musty or goatlike.

Researchers also identified two steroids present only in the teens’ body odor. One, called 5α-androst-16-en-3-one, smells of sweat, urine and musk. The other, called 5α-androst-16-en-3α-ol, smells of musk and sandalwood.

A few components of scented products also turned up, despite participants avoiding deodorant and using unscented body wash and detergent for two days prior to the study.

Notably, some compounds known to contribute to strong body odor weren’t detected, says biochemist Andreas Natsch of Givaudan, a fragrance and flavor manufacturer headquartered in Vernier, Switzerland. Those chemicals might require different detection techniques, or they may show up more after exercising or working up a sweat (SN: 7/13/21).

In future work, Loos hopes to look for those compounds and to study how BO changes at other stages of development (SN: 5/30/12).

Skyler Ware was the 2023 AAAS Mass Media Fellow with Science News. She has a Ph.D. in chemistry from Caltech, where she studied chemical reactions that use or create electricity.

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