biostudies-literatureUnknown275(1652)Roberts SCWellcome TrustPrevious studies in animals and humans show that genes in the major histocompatibility complex (MHC) influence individual odours and that females often prefer odour of MHC-dissimilar males, perhaps to increase offspring heterozygosity or reduce inbreeding. Women using oral hormonal contraceptives have been reported to have the opposite preference, raising the possibility that oral contraceptives alter female preference towards MHC similarity, with possible fertility costs. Here we test directly whether contraceptive pill use alters odour preferences using a longitudinal design in which women were tested before and after initiating pill use; a control group of non-users were tested with a comparable interval between test sessions. In contrast to some previous studies, there was no significaProceedings. Biological sciences2715-22https://www.ebi.ac.uk/biostudies/studies/S-EPMC2605820biostudies-literatureMHC-correlated odour preferences in humans and the use of oral contraceptives.PMC2605820Petrie MRoberts SCCarter VGosling LMfalseMHC-correlated odour preferences in humans and the use of oral contraceptives.Previous studies in animals and humans show that genes in the major histocompatibility complex (MHC) influence individual odours and that females often prefer odour of MHC-dissimilar males, perhaps to increase offspring heterozygosity or reduce inbreeding. Women using oral hormonal contraceptives have been reported to have the opposite preference, raising the possibility that oral contraceptives alter female preference towards MHC similarity, with possible fertility costs. Here we test directly whether contraceptive pill use alters odour preferences using a longitudinal design in which women were tested before and after initiating pill use; a control group of non-users were tested with a comparable interval between test sessions. In contrast to some previous studies, there was no significa2008-01-01T00:00:00Z2008 Dec2025-04-26T00:34:14.039Z2019-03-27T00:19:52ZS-EPMC26058201870020610.1098/rspb.2008.0825