When a man hugs a woman, she often, without quite realising it, presses her nose into the curve of his neck or shoulder. It looks as if she is searching for something. And you know what? She really is. Not consciously, of course. But her brain is quietly scanning the microscopic molecules drifting off his skin. One of the most potent of these is called androstadienone. And it can do very strange, powerful things to mood and desire.

Picture a regular morning. You wake up a bit irritated, the world feels grey, and sex seems as far away as another continent. Then your man—fresh out of the shower or, conversely, straight from a workout—comes up behind you, wraps his arms around you, and you breathe him in. Fifteen or twenty minutes later, you are already laughing at his bad jokes, your mood has lifted, and your thoughts… well, you know exactly where they have gone. You might think this shift is simply because you love him. But part of it might actually be androstadienone that just slipped through your nasal mucosa and started talking to your brain without asking for permission.

Now let’s get to the science, so you don’t think this is just another fairy tale about pheromones.

In 2013, Belgian researchers Jacob Verhaeghe, Ruth Gheysen, and Paul Enzlin published a comprehensive review in the journal Facts, Views & Vision in ObGyn. While the name might sound unusual to the uninitiated, it is a highly respectable publication. They pulled together solid studies on how androstadienone affects women. Here is the most interesting data they found:

• This compound is found in thousands-of-times higher concentrations in male sweat than in female sweat.
• Women can detect it at concentrations 100 times below the threshold of conscious smell. This means you do not technically "smell" it—you "feel" it.
• When women had a tiny pharmacological dose of androstadienone applied just under their nose (right on the upper lip), their mood significantly improved within half an hour. Anxiety dropped, and mental focus sharpened.
• And here is the really spicy part: the better the mood and the higher the focus, the stronger sexual desire became. This effect was observed even in women who were on oral contraceptives, which are historically known to sometimes dampen libido.

Why does it work exactly like that?

Here is where psychology meets neurobiology. Androstadienone is not just a "smell" in the traditional sense. It acts as a modulator on the deep parts of the brain responsible for emotions and reward—specifically the amygdala, hypothalamus, and prefrontal cortex. Essentially, it quietly whispers to your limbic system: "Hey, everything is fine, relax, it is safe here, there is a man here." And the brain believes it. When the brain believes it, the body follows.

There are notable studies, such as Lundström & Olsson (2005), where women were shown emotionally intense videos. Those who had been exposed to androstadienone reacted with a different emotional baseline. The molecule essentially works like a social buffer. And as we all know: when a woman is relaxed and in a positive headspace, sexual response comes easily and vividly.

Interestingly, the effect is highly context-dependent. This is crucial: if the man is unpleasant to you, androstadienone will not work like a magic potion; it might even cause repulsion. But if you are already drawn to him—even a little—the substance amplifies that tiny spark into a full-blown bonfire.

The hormonal connection: Cortisol and Desire

One more fascinating fact: in an experiment by Wyart et al. (2007), women sniffed androstadienone while researchers measured their physiological responses. The study found that the scent directly influenced cortisol levels. While we often think of cortisol only as a "stress hormone," it is also the hormone of physiological arousal and alertness. The study showed that androstadienone maintained arousal levels, preventing the drop in alertness that usually happens when we are bored or tired.

Furthermore, there is a biological link between cortisol modulation and testosterone. When the body is in the right state of arousal and well-being, testosterone can function more effectively. And yes, women have testosterone too, and it remains the primary driver of libido. The chemical chain of events looks something like this:

1. Male sweat releases Androstadienone
2. The molecule hits the nasal receptors
3. Mood improves and focus sharpens
4. Physiological arousal triggers readiness
5. Sexual desire spikes

All of this happens without a single word being spoken. It happens simply because you inhaled his skin.

So, the next time you notice your mood and desire suddenly soaring in the arms of a particular man, remember: it might not only be love. It might also be chemistry that is millions of years old and still works better than any artificial aphrodisiac.

Have you ever noticed that with some men your mood and desire skyrocket instantly, while with others… nothing happens, no matter how hard you try? Maybe it is not just about him as a person. Maybe it is also about what he is quietly releasing right under your nose.

Sources:

• Verhaeghe J, Gheysen R, Enzlin P. Pheromones and their effect on women’s mood and sexuality. Facts Views Vis Obgyn, 2013.
• Wyart C, et al. Smelling a single component of male sweat alters levels of cortisol in women. Journal of Neuroscience, 2007.
• Lundström JN, Olsson MJ. Subthreshold amounts of social odorant affect mood, but not behavior, in heterosexual women when tested by a male. Hormones and Behavior, 2005.