Victoria Costello

According to evolutionary psychologists, the instinct to reproduce still wields a big influence over who you find hot, or not. It takes two lusty chemicals, dopamine and testosterone, just to free any two people from their instinctual fear of strangers. And then make them forget about their last romantic heartbreaks.

Once you're open and aroused, two hard-hitting natural stimulants (norenpinephrine, the “fight or flight” agent in our brains, and PEA, the chemical associated with “love at first sight”) are released to get you hooked and transport you from that bar stool to a bed. Without these hormones and neurotransmitters, happy hours and dating websites would be lonely places.

Some Timeless Mysteries, Solved

Let the fog lift.

Why "I Have a Headache" is not the end of the conversation

When thinking about the chemistry of female arousal, it's important to distinguish between a woman's sexual desire and her response to arousal. The former helps stoke the latter, but it's not essential. This is something that hasn't always been understood, resulting in far too many standoffs between horny men and ostensibly disinterested women across the land.

Here's a surprise. Sexual desire by itself is an uncommon reason for women to initiate sex or for a woman to agree to sexual activity. Women have sex for many other reasons before desire: to make an emotional connection, to please a partner, even to avoid a spat. Meanwhile men, at least until they reach their forties, are walking around with a seemingly inexhaustible supply of sexual desire.

Men’s Sexuality is Simple and Constant. True or False?

There is a mistaken impression out there that male sexuality is a one-act play, the course of a man's arousal and sexual satisfaction therefore a no-brainer, the changes over his life cycle minimal. Partly, this misunderstanding has to do with the fact male genitalia are external, and thus more easily understood (and aroused).

But as any man or any woman in a long term relationship is well aware, there are moods and seeming mysteries attached to men's sexuality too. There are times when a man in his thirties and forties cannot achieve an erection and he doesn't have a clue why he can't. There are times when stress feeds his sexual desire and still others when disappointment over some perceived failure in his life kills all thoughts of sex. Could it be that a man's emotions have more to do with his sexual performance than he thought? This would put a dent in the "man as sex machine" theory, and that might not be a bad thing.

One major difference between men's and women's sexual response has to do with a woman's greater susceptibility to fears and anxieties that can distract her from sexual arousal.

Why Women Lose Interest Midstream

Unlike a man, who once he gets half way there is a goner, a woman can lose interest in sex at any moment up to and including orgasm. For a woman to stay turned on, the fear-worry circuit in her brain must be turned off.
How does fear or worry cause a woman to turn off sexually? Negative feelings such as fear and anxiety are modulated in the amygdale. When activated the amygdale sends its chemical messengers to the frontal cortex. If emotional distractions flare up for a woman during any point in the arousal stage, the announcement goes out loud and clear from her brain to the rest of her body: "forget sex."

News to Use

A man's high testosterone level in the morning makes him most virile upon waking. This explains why men often wake up with an erection. Comparatively, he's got less desire at noon or dusk, especially as he ages.
Studies have shown that men with the highest testosterone levels and the most handsome men are more likely to cheat on their partners and be divorced. Could this be evidence of too much of a good thing? Researchers say the evidence points to exactly that conclusion.

Sexual desire and testosterone levels are linked in an unending feedback loop in men. Testosterone is increased through his regular sexual activity, and high testosterone leads him to want and have more sex. In addition to increasing a man's sex drive, a higher level of testosterone is beneficial to a healthy heart and brain. It produces a buoyant effect on his mood and energy level.


That's it for now. Suffice to say, from the forward march of evolution to what you ate for dinner, everything you do, think, feel, and consume through your five senses, as well as what you remember personally--all of it comes into play in the chemistry of love. Those are a lot of forces at work. The good news is that each part of the whole, meaning your brain, your feelings and every cell in your body, is elastic and fluid. You can always change things for the better. It's the wonder of chemistry.