What do women and men smell like? The answer will surprise you.

Women smell like onions or grapefruits, and men smell like cheese, reports Christian Starkenmann, who supervised the tests of the Geneva-based company Firmenich. Onion vs. Cheese Analysis of sweat samples revealed that women's sweat gland secretions contain large amounts of odorless sulfur compounds. When these compounds mixed with bacteria from the armpits, a chemical reaction created thiols—known for their onion-like odor. Men smell differently. They were found to have relatively high concentrations of fatty acids, which, when combined with bacteria, created a cheesy odor. Sweat Sample Experiment The tests were conducted by the Swiss company Firmenich, which researches scents and flavors for the food and cosmetics industries. Scientists collected underarm sweat samples from 25 women and 24 men who sat in a sauna or pedaled an exercise bike for 15 minutes. A woman's scent is more unpleasant The researchers also recruited independent judges. They rated the odor of women's sweat as less pleasant than that of men's. Social conditions inhibit further testing Not all scientists are convinced that a similar experiment can be replicated outside of Switzerland. The reasons are varied: people from around the world have different diets, inherit different genes, use different body care products and cleaning products, and, finally, wear a wide variety of clothing. Suggestion for deodorant manufacturers The Geneva-based company's findings could serve as a guide for formulating deodorants for women or men. It will be necessary to neutralize precursor compounds or block bacterial enzymes.