The Pill Affects A Woman's
Choice of Her Mate
Despite nearly 50 years of access to the pill, some women
are clueless about side effects that doctors might not bother
sharing, and some that are just being discovered.
"Doctors in general tend to hesitate to suggest things to
the patient," said Dr. Nanette Santoro, director of reproductive
endocrinology at the Albert Einstein College of Medicine in
New York City and a member of The Endocrine Society.
"These are things that wouldn't have a major health impact."
Santoro said, with limited time in appointments, doctors focus
on the major side effects that can pose a health risk: the risk
of blood clots among smokers, high blood pressure, and stroke
with some migraine headaches, for example.
But Santoro knows of many less-pressing and idiosyncratic
side effects from the pill that don't always make it into the
Women on the pill may suffer a lackluster sex drive, mood
swings, or even extra sinus pressure, she said.
"Some women may notice their sinuses are a little stuffier,"
Santoro explained. "It speaks to the bigger point that pills
do affect the mucus production of the body."
That means mucus, whether on the cervix or in the nose, can
This August, research began to confirm another strange connection
between the birth control pill and a woman's nose.
In a study of about 100 college students in the U.K., scientists
found that the pill may change how women find a man's scent
The study collected body odor from volunteers and put it in
jars for the ladies to smell. Among the 200-300 different chemical
compounds in sweat, researchers tried to draw a connection to
the woman's reaction to the sweat and a by-product in the sweat
from the major histocompatibility complex (MHC) genes, which
contribute to the body's immune system.
Since the late 1990s, research has shown that women find the
scent of a man more attractive if he has MHC genes that are
different from their own, and less attractive if he has similar
But that all may change two months after a woman goes on the
The Pill May Change How You Choose a Man
"In the pill-using group, there was a significant shift in
their preference for men who had more similar odors," said Craig
Roberts, a co-author of the August MHC study appearing in the
"Proceedings of the Royal Society B," and a lecturer at the
University of Liverpool in the U.K.
Roberts said the women in the control group who didn't take
the pill only started to find men with different MHC genes more
attractive in the second round of body odor sniff tests.
"It's an odd thing to do, smell odors in jars," Roberts said.
"We don't know the effects in the real world, but it does carry
implications for women who are using the pill, and you can extrapolate
from this very artificial laboratory study quite a long way."
For example, "They may choose someone they may not choose
otherwise," he said. In theory, Roberts said a woman may choose
a man while she's on the pill and feel fine, but subconsciously
find her mate less attractive if she goes off the pill.
"There is evidence that couples that are more MCH similar to
each other have more difficulty conceiving, and they have more
miscarriages," added Roberts, who has also cited research that
women who marry men with similar MCH genes are more likely to
have an affair.
Aside from chemical conjectures, Einstein's Santoro has heard
straight from her patients that the pill can affect one's sex
"Clearly, pills suppress androgen production in the ovary,
so, to the extent that androgen levels drive sex drive in women,
it could affect them," said Santoro, who is also a doctor with
the Montefiore Medical Center in New York City.
"It's also possible for some women, especially if they're
Catholics, to have a libido problem. ... Once they start on
the pill, it may reduce their enjoyment in some way out of guilt,"
Santoro said many of her patients tend to think of the pill
as an off-switch for hormones, but in truth, the pill exposes
women to higher levels of hormones to overcome their own cycle.
Other Strange Side Effects From the Pill
"Because the pill in a lot of ways produces a pseudo-pregnant
state, some of the side effects of pregnancy are noticed in
the pill," Santoro said.
That means women on the pill may experience heartburn, or
constipation, or sleep disturbances, either as insomnia or extra
Santoro said doctors are also less likely to get into great
detail about weight changes.
"We tell our patients that weight doesn't change if you take
the pill ... but among the individual women, there may be some
who gain and some who lose," said Santoro, who added that large
studies on the subject might cancel out the average weight changes
experienced by women on the pill.
Overall, Santoro said she'd spend more time talking about
the pill's more serious health risks and side effects with a
"Women over 35 who smoke more than 10 cigarettes a day --
they shouldn't be taking the pill at all," she said.
For patients who have migraines with aura, which refers to
feelings and symptoms noticed shortly before the headache begins,
"they should not take pills without making sure everybody's
Santoro said although research hasn't drawn any hard-and-fast
conclusions about side effects from taking the pill for an extended
period of time, many of her patients have decided to give the
hormones a break.
"It's outdated, but some women feel better if they take a
little 'pill holiday' now and then," she said.