But messing with your hormones can alter your sex life in positive and negative ways.

Heres what you better know, as a pill-taker or as the partner of one.

Each one has different dosages of hormones that help the body prevent pregnancy.

Most pills contain a combination ofprogestinandestrogen, while some contain only progestin.

These hormones prevent your body from ovulating (releasing an egg from your ovary).

With no egg, theres nothing to be fertilized, and no way for you to get pregnant.

How the Pill Affects Sexual Desire

The Pills relationship with sexual desire is complex.

Its also, unfortunately, one of the least-researched aspects of potential side effects.

But here are a few of the possibilities you might encounter.

The Pill itself can lower levels of testosterone in a womans body.

If youve ever felt particularly horny before your period, that spike may have been the culprit.

Estrogen can also increase levels ofsex hormone-binding globulin(SHBG).

SHBG attaches to testosterone and makes it biologically unavailable, further decreasing testosterone levels.

The Pill can also drastically decrease the amount oflubricationyour body creates.

This can make sex uncomfortable or evenpainful.

When your girly bits hurt, sex does not seem particularly enticing.

For example:

Knowing youre safe from getting knocked up can be a huge relief.

That sense of relaxation in and of itself can naturally increase your desire for sex.

(Remember that while the Pill guards against pregnancy, it does nothing to protect you against STIs.)

Some women use the Pill to skip periods entirely.

Being on the Pill typically means the end of menstrual cramping.

Not having to deal with that pain may make you more open to sex.

Some pills decrease acne.

If you have serious adult acne, you know that it can make intimacy seem far too intimidating.

More self confidence can make you feel more comfortable having sex.

Some women will experience mild to severe spotting while using the Pill.

Mild spotting is normal, but moderate to heavy amounts of fluid should be checked out by your doctor.

Ditto to spotting that goes on longer than a week.

Some researchers speculate thatthe Pill changes the types of male partners youre attracted to.

Our noses can sniff out the Major Histocompatibility Complex (MHC) genes in other people.

These genes play a large role in healthy immune systems.

When women are on the Pill, theyre actually more attracted to men with similar MHC profiles.

Terrifying thought for couples who met while the woman was on the Pill, isnt it?

The Pill can make you moody as hell.

Its hard to have sex when youre weeping to theSarah McLachlan SPCA commercial.

Of course, every woman will have different responses to the Pill, but these are pretty common responses.

Your body may respond far better to one pill than to another.

Be grateful that you dont have to deal with this crap!

Illustration by Tara Jacoby.