Jelly Baby in a test tube

Implications of sex differences

If we want to improve health, should we treat males and females differently?

Men and women sometimes respond differently to certain drugs or suffer different side-effects. This could have important consequences for the development of new drugs, and for their use. Drugs, or vaccines, could come in ‘male’ and ‘female’ forms. Tailoring of medicines according to sex may become more common as the mechanisms of disease, and of patients’ responses to drugs, are better understood.

One area in which sex differences do influence treatment is anaesthetics. The dose of opioid drugs used is tailored to a patient’s weight and sex. Men and women also respond differently to the anti-HIV medication nevirapine – women are more likely to suffer a skin rash.

However, incorrect assumptions about sex differences can also have medical consequences. Cardiovascular disease, for example, is often seen as a male problem, but it is common in women too. Studies have shown that GPs underdiagnose cardiovascular problems in women, who tend to have a different range of symptoms from men.

Some other differences in medical practice arise from women’s reproductive roles. Certain drugs may affect a developing fetus, so are not given to pregnant women. Women of child-bearing age are not included in clinical trials, so most drugs are not actually tested on women before they are introduced.

This exception is because of the Thalidomide episode in the 1960s. Women were given a new ‘wonder drug’ to treat morning sickness. Sadly, Thalidomide turned out to affect limb growth in unborn babies. Since then the testing of medicines has been much more rigorous, but women still tend to be under-represented in clinical trials. For instance, a 2009 study found that three-quarters of cancer studies under-represented women.

Lead image:

Jelly Baby in a test tube, illustrating personalised medicine.

Wellcome Library, London CC BY NC ND


About this resource

This resource was first published in ‘Sex and Gender’ in January 2006 and reviewed and updated in October 2014.

Statistics and maths, Medicine, History, Health, infection and disease
Sex and Gender
Education levels:
16–19, Continuing professional development