Identity, not sex or menstrual cycle, drives human body odor and attractiveness to Anopheles gambiae mosquitoes

Introduction

Mosquito host-seeking behavior is a key driver of malaria transmission, yet the biological factors underlying variation in human attractiveness remain unclear. Physiological states such as pregnancy and menstrual cycle have been proposed to increase of human odor variability and modify attractiveness to mosquitoes, but evidence remains inconsistent. These assumptions have raised concerns about variability in female odor cues limiting the inclution of women in research and the generalizability of findings. To address this gap, we investigated whether sex and menstrual cycle consistently influence human body odor and attractiveness to Anopheles gambiae, a primary malaria vector.

Methods

We conducted two longitudinal studies in which body odor samples were repeatedly collected from women at three menstrual cycle phases across up to four cycles, and from men at matched intervals. Skin volatile profiles were analyzed using gas chromatography, and mosquito attraction was assessed using a uniport olfactometer assay with worn nylon sleeves and socks.

Results

Mosquito attraction did not differ between male and female participants at any timepoint. Attraction levels and volatile profiles remained stable within individuals across repeated measurements. Individual-level differences explained most of the variation observed in both mosquito attraction and odor chemistry, accounting for up to 64% of the variance in foot volatiles and 59% in arm volatiles. In contrast, sex and menstrual cycle phases showed only marginal effects.

Conclusion

Our findings refine and challenge assumptions from prior studies by demonstrating no consistent effect of sex or menstrual cycle phase on mosquito attraction. Instead, stable, individual specific odor signatures were the primary determinants of both volatile composition and attractiveness to Anopheles gambiae. These results highlight the intrinsic stability of human body odor and emphasize the importance of interindividual variation, rather than sex‑related physiology, in shaping host attractiveness.