We’re Just Now Learning How Hormones Affect Our Brains

If you’ve ever found yourself freaking out before a meeting, you’ve experienced shifts in cortisol, the “fight or flight” hormone which plays an important role in general stress regulation (studies have found that burnout and complex grief, for example, have been associated with high cortisol levels).

Mood and energy shifts are likely due to changing levels of progesterone and estrogen, the two primary female sex hormones that also influence mood, cognitive functions and libido.

When you feel a sense a satisfaction from a meal, that’s elevated dopamine, the brain chemical for reward-driven learning, pleasure and satisfaction.

If you hug someone and feel more connected to them, oxytocin — the neurotransmitter and hormone of love, responsible for social connection and bonding as well as trust, herd mentality and social conformity — has increased.

That gut feeling you keep experiencing? It’s likely serotonin — a hormone regulating mood and social behavior that’s mainly found in the intestine — speaking.

Together, hormones influence our level of energy, ability to focus, quality of sleep, experience of stress and anxiety, mood, sociability and cognitive function. For women, hormones also follow a pattern. A month-long pattern. But the physiological process of how hormones manifest in our bodies still isn’t broadly understood, even by doctors. And though we’re beginning to discuss their effects, this conversation is still surprisingly speculative. Often, the subtext is that hormones lead to irrational behavior, that they’re a problem.


Researchers in the field, like Simon Baron-Cohen, author of several studies on gender differences and the brain, admit that the topic of sex difference in psychology is “fraught with controversy” and a field “prone to misunderstanding and misinterpretation.”

“It’s an area people didn’t want to enter for many decades because of its political incorrectness and [risk] of being misunderstood,” but increasingly, researchers are starting to ask more open-minded questions, “without fear of being accused of having a sexist agenda,” explains Baron-Cohen.

Most of our scientific knowledge on the topic of hormones and the brain has been acquired via animal studies — the majority using male animals — which is about as problematic as it sounds. However, new research offers fascinating findings.

In one study, researchers at the Max Planck Institute for Human Cognition and Brain Sciences performed brain scans on a patient for two months and discovered that her brain literally changed every month in sync with her hormones.

“In parallel to the rising estrogen levels leading up to ovulation, the Hippocampus (a brain area essential for memories, mood and emotions) also increases in volume — the volume of the grey matter as well as that of the white matter,” explains Claudia Barth, co-author of the paper.

Only one female was observed in this study; how changes in brain structure affect behavior and specific cognitive ability are still not fully understood.


There are tons of reasons to investigate women’s brains in relation to their cycles aside the obvious, which is that, well, half of the world happens to have a female brain. Here are just a few:

PMDD: This kind of research can help us understand premenstrual dysphoric disorder (PMDD), which affects one in 12 women in the days leading up to her period. PMDD is a more extreme case of PMS and women who suffer from it complain of severe physical and psychological symptoms such as listlessness or mood swings comparable to a depressive episode. “To get a better understanding of this disorder, we first have to find out which monthly rhythm the brain of a healthy woman follows. Only then can we reveal the differences in persons affected by PMDD,” says Julia Sacher, a researcher at Max Planck Institute.

Addiction: Addiction and recovery could be partly modulated by hormonal shifts in the menstrual cycle. Understanding these factors could offer beneficial insights into personalized treatments for recovery.

Per a BioMed study, “Preclinical and clinical research suggests that ovarian hormones (i.e., estradiol and progesterone), which fluctuate over the course of the menstrual cycle, influence smoking behavior, and relapse vulnerability.”

Menopause: Perhaps the most misunderstood and interesting phase of a woman’s life is menopause, which is associated with brain fog and some fifty other symptoms (yes, really).

According to Dr. Marianne D. Legato, a pioneer in the field of gender-based medicine, low levels of estrogen — which tend to occur during menopause — “impair our ability to think clearly and certainly impact memory.”


Birth control: The effect of birth control on both brain and hormones is becoming an increasingly hot topic, with suggestions that it is depressing the hell out of us. The most popular oral contraceptive options prevent ovulation and inhibit the usual hormonal cycle, which has a direct effect on mood-regulating chemicals in the brain, like serotonin. In addition, at least one study has found significant differences between the brain structures of women who did or didn’t take oral contraceptives — although it is not clear yet what those differences might mean.

The rewards of studying female hormones and the brain outweigh the risks of misunderstanding, bad research methods and discrimination. There are so many interesting and important things that happen to our brains which we do not yet understand. Education and information about the menstrual cycle and behavior could enable us to better predict changes, and adjust and adapt. Controversial, yes, but worth it.

Alexi Surtees and Daniele Orner-Ginor are co-founders of Ovary, a community and data company addressing knowledge gaps in women’s health. Learn more here. Illustrations by Maria Jia Ling Pitt. 

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  • Lil

    More research needs to be done on hormones. Especially on it’s relationship with birth control (BC). There’s so little official information on the side effects of birth control… Doctors rarely ever say that it can cause depression, which it did to many of my friends and I.

    • Meg S

      I can’t take birth control because it altered my moods so drastically. Depression, mood swings, anything that I felt was normal before and during my cycle was amplified by 10 and lasted all month. I’m surprised my boyfriend didn’t break up with me. It did help my cramps, but I’d rather have the cramps than the awful moods. It was worse in the winter when my seasonal depression kicks in. I could hardly get out of bed.

    • Emily

      I completely agree. I became depressed and had horrible, drastic mood swings while on birth control, and this has happened to many of my friends as well. I ultimately switched to an IUD, which is better for me.

  • I find this topic endlessly fascinating and, not just that, but also downright fucking important. The more I hear about the influence of hormones on our lives (and the more I note the influence they have on my own life) the more pissed I become that this topic has been pushed under the rug for so many years. That PMS is often laughed off as a joke, as this silly thing that makes women irrational and moody once a month, rather than something to be taken seriously and explored further.

    ANYWAY, thank you for this article. I for one would love for this to be a recurring series of sorts on MR.

  • Kate Long

    Hormones are fascinating! My friend and I both recently stopped taking the pill (neither of us are trying to get pregnant) and were talking about how much better we feel after quitting. It’s especially interesting to me because when I first started taking it (as a teenager, to stop me getting my period every other week) it made me feel so much better! Throughout this whole process (of figuring out why certain pills/patches/IUDs/shots/rings/etc. worked to regulate my cycle and then stopped) it was amazing how little certainty there was in the area and how much of it is just trial and error.

    Ultimately there are so many reasons why taking the pill (or other hormones) may or may not be the right decision for any particular person at any particular time, but it would be helpful to know more about the potential effects any medication can have so you can make an educated decision for yourself. More science please!

    • dietcokehead

      Man, it was SHOCKING how much better I felt when I left hormonal bc (Mirena briefly buffeted by Nuvaring) for Paragard. I ain’t even mad about having periods again. I just feel ok, finally.

      • Meg S

        I need to look into this. I can’t take any hormonal birth control because of how it affects my moods.

  • Abigail Larson

    I recently had Nexplanon removed because I was convinced that I was clinically depressed. I went to my doctor expecting to walk out with a prescription, and instead he asked me which birth control I was on. He then made an appointment to have it removed (it’s a small rod that’s placed on the inner part of your bicep, for anyone who’s wondering). When I woke up the next morning, I was a completely different person. My husband couldn’t even believe that I was back to my normal self. I don’t know, you guys. This whole birth control thing really scares me because it seems like it’s still misunderstood and can have such horrendous side effects.

    • ihaveacooch

      this is wild. i’m glad you’re feeling better but how scary!

      • Abigail Larson

        I know right? Some days I couldn’t even get out of bed because I felt so out of sorts. The doctor who removed it mentioned that she had seen many different patients exhibit the same symptoms, and she was convinced it was related to that particular form of BC.

    • I feel ya! I stopped using the nuva ring 2 months ago, after 10+ years of being on birth control. I have never felt better, happier, confident, and more in touch with my self.

  • Jane M.

    I think it should be noted that serotonin and dopamine are, first and foremost neurotransmitters. While hormones and neurotransmitters share many similarities, they operate within distinct systems, namely the endocrine system and the nervous system, respectively. For example, although dopamine does sometimes act as a hormone, this is exclusively in the case of stopping the release of breast milk. I.e. its major functions are that of a neuurotransmitter.

  • Jennifer

    Awesome article!

  • Meg Ramsay

    This is indeed a very interesting topic, which I wish EVERYONE, women and men alike understood better.

    It would be so beneficial to everyone, because hormones drive a huge part of our life, health, fitness and wellness. Why is “being hormonal” joked about, even mocked by others? Of course, a little joking around never hurt anyone, but there’s an underlying problem: people genuinely don’t understand their hormones, what they do, or how you can begin to control/manage them in your lifestyle choices.
    To be completely honest, I have suffered from PMDD for about 5 years. Some months are worse or better than others, but I can’t stress how LIFE ALTERING it is. Just as this article describes, the emotional rollercoaster is REAL. The depression/agressive episode is REAL, and I’m not exaggerating.
    However, my doctor has never been able/willing to discuss it with me. I’ve been told to get a therapist, and have been given the implication that “it’s just how you are” – which truth be told is horrifying and completely untrue, because a few days later everything is fine and back to normal.

    So yeah, basically… We really need to get our shit together, and start understanding hormones way better and stop shaming people who are affected by them. Peace to all of the women out there.

  • adrian56435

    Important content you write in here and i read the article with attention. As a human we need to know about hormones and i think it help us to get information about brain. Most of the people are like this content.