Mushroom alcohol makes some women more attractive to mosquitoes than others

It is well known that human scents vary in their attractiveness to mosquitoes, but the chemical explanations as to why this is so have been lacking. Now, an SLU-led study shows that menstrual cycle and pregnancy influence attractiveness to mosquitoes, and the scent of highly attractive people was found to contain more so-called mushroom alcohol.

Scents are crucial for most important events in a mosquito’s life, and it has been known since the late 1950s that a person’s scent determines how attractive she is to mosquitoes seeking a blood meal. And since then, researchers have identified a number of factors that can influence how a person smells and make her more or less attractive to mosquitoes. These include blood type, skin microbiota, illness, and alcohol consumption. But strangely enough, we didn’t know the chemical mechanisms that make this true.

“We’ve known quite a bit about the scent components that mosquitoes use to find humans in particular. But our study is the first to provide a chemical explanation for people’s varying attractiveness,” says Rickard Ignell, who has long studied the sense of smell in mosquitoes capable of spreading serious diseases.

Rickard Ignell and his colleagues built on earlier studies of malaria-carrying mosquitoes, in which pregnant women were found to attract up to twice as many blood-seeking mosquitoes as other people, significantly increasing the risk of infection. In this study, the researchers chose to use yellow fever mosquitoes and evaluated how attractive 42 women were to female mosquitoes seeking blood. What they found was that attractiveness was influenced by the phase of the menstrual cycle the woman was in, and whether she was pregnant.

The next step was to collect scent samples from each person and investigate the reaction of the mosquitoes’ antennae to the chemical compounds in the scent and identify them. Human skin and exhaled air consist of hundreds of compounds, and among these, the researchers identified 27 volatile compounds that could influence how attractive a person is to mosquitoes.

One particularly interesting compound was octenol (also known as mushroom alcohol)—which was present in higher amounts in the body odor of highly attractive participants and in pregnant individuals. Octenol is a compound formed through the breakdown of sebum on the skin.

However, attractiveness is not determined by individual substances, and there were attractive persons who emitted only moderate amounts of octenol. The decisive factor is the combination of substances the scent contains and the proportions in which they are present. The latter also determines whether the women are less attractive to mosquitoes.

One way to analyze human attractiveness to mosquitoes is to try to create a synthetic human scent based on what the mosquitoes can smell. In this study, the researchers developed scent mixtures designed to correspond to low, medium, and high attractiveness. When the researchers then tested these scent mixtures in behavioral studies, it turned out that the mosquitoes behaved accordingly.

“So, we’ve made some progress, but we’d need to increase the number of people in the study and follow them through their menstrual cycle and pregnancy. It would also be interesting to compare these results with people who don’t menstruate, as well as to investigate whether other species of biting mosquitoes use the same strategy to distinguish between us,” says Rickard Ignell.

The scientific article
Annika Hinze, Anais Karine Tallon, Betelehem Wondwosen, Mengistu Dawit, Sharon Rose Hill, Björn Bohman & Rickard Ignell. 2026. Cyphers and cycles – A chemical basis of the differential attraction of mosquitoes to human odor. iScience.
https://doi.org/10.1016/j.isci.2026.115575