By Kathleen Gilbert

LIVERPOOL, United Kingdom, August 12, 2008 ( – A recent study by the University of Liverpool found that the contraceptive pill may adversely affect a woman’s natural ability to choose a genetically favorable mate. 

The ability to choose a genetically favorable mate is ascribed in part to pheromones, chemicals that can cause behavioral changes in the opposite sex. These chemicals also contain the genes involved in immunity response.  When these genes interact with normal skin bacteria, they influence an individual’s particular body odor. 

Research has indicated that women tend to be more attracted to the odors of men whose genes are more unlike their own; this instinctive attraction is key in helping ensure a match that is genetically advantageous to a couple’s offspring.  If a couple’s genes are too similar, they are at an increased risk of miscarriage and difficulty conceiving, and if they do conceive, the child may have a weakened immune system.

Yet this natural sense may be endangered by the use of oral contraceptives.  The research team conducting the study asked women to indicate their preferences of six male body odors before and after initiating use of oral contraceptives. 

According to Craig Roberts, a Lecturer in Evolutionary Psychology and one of the researchers in this study, women taking the pill began to prefer men with more genetically similar odors.  Addressing the implications of such a disruption, he states: “Not only could [gene] similarity in couples lead to fertility problems, but it could ultimately lead to the breakdown of relationships when women stop using the contraceptive pill, as odour perception plays a significant role in maintaining attraction to partners.”

These claims are not the first to question the pill’s impact on hormone activity and sexuality.  Dr. David Brownstein, commenting on a study linking oral contraceptives to increased arterial plaque, emphasized the precarious balance of hormones needed for good health, a balance disrupted de facto in pill users:

“Oral contraceptives totally disrupt the normal hormonal cascade. When the hormonal system is disrupted, cardiovascular disease, cancer, fibromyalgia, chronic fatigue syndrome and other serious illnesses will increase.  My clinical experience has clearly shown that it is impossible to adequately treat these illnesses if there is an imbalanced hormonal system.”  (Read “Oral Contraceptives May Be Linked to Atherosclerosis”

In addition to altering women’s natural attraction to suitable partners, the pill also permanently damages sex drive over long-term use, according to one study (Read 

Related coverage:

Birth Control Pill May Cause Prostate Cancer and Bladder Disease in Mothers’ Children

The Pill is Deadly to Babies and Women

Online Video: Noted Endocrinologist Explains How the Birth Control Pill Causes Abortion