In this monologue, Kayla Osterhoff recounts how her mother’s opioid overdose and the failures of the healthcare system propelled her into a doctoral study of neuropsychophysiology. Her research uncovered profound sex differences in brain structure and chemistry, highlighting that the female brain—particularly the prefrontal cortex, hippocampus, and hypothalamus—contains high densities of estrogen and progesterone receptors, which confer enhanced decision‑making, memory, and emotional intelligence. She explains that the female hormone cycle consists of four distinct monthly phases, each producing a unique cognitive "superpower" and biochemical signature. By understanding these phases, women can align biohacks such as fasting or cold exposure with periods of higher stress tolerance, avoiding the shift from beneficial eustress to harmful distress. Osterhoff also notes that the cyclic rhythm persists beyond reproductive years, influencing perimenopausal and post‑menopausal physiology, even when hormone replacement therapy is used. She emphasizes the principle of self‑regulation—training the nervous system to respond adaptively rather than reactively—and argues that true empowerment comes from women granting themselves permission to deviate from male‑centric health advice and to partner with their own bodies.
Chapters
I come from a family history of addiction and mental health issues. My mom actually ended up having an overdose from opioid addiction, and that really caused all kinds of upheaval in our family, but it caused her a lot of issues with her brain function and her mental health specifically. And at that point, I was so angry with the healthcare system because that was the culprit for my mother's addiction. All of the drugs that she was taking were prescribed and not only were they prescribed, but they were taken as prescribed. And that really led her down a dark path. So I was really just looking for answers. Why did this happen to my mom? And how can doctors who are supposed to do no harm end up causing a life-threatening addiction? And not really address the root causes of what is causing the pain or the surgeries or whatever it is that ended up giving those kind of pain medicines, right? I was doing a lot of research to help my mom and get her in with, you know, functional neurologists and really learning about the brain and the intricacies of everything there. And so that led me to pursue my doctoral degree in neuropsychophysiology. I really found some interesting things about women's health and women's psychology, women's neurology, and women's biochemistry, and how everything is really interrelated. And that a woman's biology has a cyclic nature to it. Unlike our male counterparts that are more on more of like a repeating 24-hour system, the female system, meaning the whole body and all the systems involved in it, not only the reproductive parts,, but the whole body really follows a monthly cyclic rhythm. And then starting to dive into that, I found all kinds of interesting research and information and putting it together, really learning about the female biorhythm as the key or the missing link to feminine health, not only cognitive health and function and psychological health and function, but women's health in general. Yes. It's really interesting because women represent 51% of the world's population, right? However, 51% of the world's population remains this mystery. We don't know as much as we know about male biology, for instance, about feminine biology. And just for instance, I've studied the health sciences, the hard sciences my whole life through to a terminal degree. And nowhere along the path did I ever take any science class on women's biology specifically, or women's physiology specifically. Out of 80 or so brain areas that have been studied, looking at the differences between female and male brains, the female brain is more active in about 70 of them. There are a couple of areas that are specifically impacted and operate a different way. In the female brain, which is the prefrontal cortex, the hippocampus, and the hypothalamus. Now, these three areas are really interesting because these are areas of the brain that are associated with leadership. So decision-making, acuity, memory consolidation, emotional intelligence. These are areas of the brain that are key for those functions specifically. So women kind of have an enhanced ability for those specific cognitive functions. And the reason why is because when you look at these areas of the brain, they actually have high densities of estrogen and progesterone receptors. So estrogen and progesterone are not only female sex hormones. They are actually really important neurochemicals. So as estrogen and progesterone ebb and flow throughout the month, right, This actually changes the way that our brain functions throughout the month. The female hormone cycle with its 4 specific phases has an interesting impact and a very different cognitive function and biochemical signature for each of the phases. And so technically women have different cognitive, what I call superpowers during each phase of their hormone cycle. That if they understand this, they can actually leverage that for higher performance and better health. I don't think a long-term fast is necessary or, you know, maybe even safe for every woman. It really depends on your situation and what your goals are and what's going on with your health, what's going on with your stress levels. That's really important is you have to understand your stress threshold and if it has been surpassed, because if you do something like fasting, you have to understand that even though that is a form of eustress, right? Positive stress. That can cause what is called hormetic stress, which helps the body to grow, right? Or it helps us to grow and become better and more resilient. But even eustress becomes distress if our stress threshold is already met. However, it's important to understand that there are certain times during our cycle where our stress threshold is naturally higher and naturally lower. So this also has to come into consideration when you're choosing your biohacks. Because things like fasting or even cold thermogenesis, again, positive stress, but that becomes distress if you're already surpassed your stress threshold. So it's important to know that yes, we have these 4 phases of our monthly hormone cycle, right? But women also have different phases of their life cycle that change this monthly cycle. So what's interesting and not researched at all is that women who are postmenopausal or even perimenopausal, menopausal, but even women who are post-menopausal still report having a cyclic nature to their biology and physiology. And so my hunch is that because we spend so many years of our life in this cyclic monthly rhythm with our entire physiology, not just our reproductive system, our biology is really set to that pace and groomed to function in a cyclic nature. And that just doesn't end because we are post-menopausal. Even if you're taking hormone replacement therapy in the form of birth control, or if you're taking hormone replacement therapy, you know, through perimenopause to help regulate your cycle, you will still go through all 4 phases, though your phases may be longer or shorter, but you can start to track this by kind of tracking the way that you're feeling and listening to your body. One quote that I love that I actually got from one of my professors is that you can't control anything. You can only self-regulate. And so that's a nerdy neuroscience reference, but you know, self-regulation is the body's ability through the nervous system to regulate itself in response to stimulus so that we don't have those big cortisol dumps. And so that we don't get overtaxed and use our resources to become very reactive. Right. So the ability to control anything in our lives is an illusion. We really can't control the things in our lives, but we can control essentially the way that we react to those things through taking care of our neurological function and really training our nervous system to be more resilient, right? Permission not only comes from the outside world for women to do things differently, but it first comes from ourselves. And that tends to be the hardest step because allowing ourselves, first of all, knowing that our bodies operate differently, that helps, that helps for us to give ourselves permission. But then knowing like, hey, my body is brilliantly designed and it actually knows exactly what it wants and needs. I just need to listen to it. I need to come into partnership with it. So kind of guiding women through that first step in Yes, it's okay to do things differently. You don't have to follow all of the recommendations and advice of your favorite influencer if it doesn't feel in alignment with you, which it probably doesn't because that influencer is a man, right? So allowing yourself to do things differently can be the hardest first step, but it's the most important.
