How Your Hormones Actually Work - Oestrogen, Progesterone & Testosterone in Plain English (Ep 2)

Have you ever felt like something has shifted — like you don't quite feel like yourself anymore — but you can't put your finger on why? So many women are living with anxiety that came from nowhere, bone-deep exhaustion, broken sleep, weight that won't budge and a fog they can't shake — without ever realising it could be perimenopause. I was one of them.

I saw five different doctors trying to get answers. Not one of them told me the same thing.

This week I'm taking you one level deeper — because when you understand how your three key hormones actually work, everything starts to make sense: your symptoms, your treatments, and why one doctor says one thing and the next says the complete opposite. And more than that — understanding these hormones is how you learn to recognise what your body is telling you, and how you advocate for yourself when something doesn't feel right. This is the episode I needed before I walked into any of those appointments — no jargon, no agenda, no medical degree required.

In this episode:
→ My experience with five different doctors — and what went wrong
→ Oestrogen: the three types, what it does, and why fluctuation matters more than decline 
→ Progesterone: the calming hormone nobody talks about — and why women without a uterus still need it 
→ The crucial difference between synthetic hormones and bioidentical — and why it matters 
→ Testosterone: the forgotten hormone, and the global testosterone crisis leaving women behind 
→ The hormonal hierarchy: cortisol, thyroid and insulin resistance 
→ The exact blood tests to ask your doctor for — and what to look for in the results → Why understanding your own hormones is the key to recognising your symptoms and advocating for yourself

BLOOD TEST CHECKLIST — take this to your appointment: Foundational: Full blood count · Iron studies (ferritin) · Thyroid panel (TSH, Free T3, Free T4) · Vitamin D · Vitamin B12 · Fasting glucose & insulin (or HbA1c) · Lipid panel Hormone panel: FSH · Oestradiol (E2, day 2–3) · Progesterone (day 21) · Total testosterone · Free testosterone · SHBG · AMH (optional)

If you've ever been made to feel like it's all in your head — it isn't. Understanding your body is how we take our power back.

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Ready to work with me? The Peri Protocol is my personalised coaching program for women in perimenopause and menopause. Apply here → www.kirstencookecoaching.com/apply

Grab your free guide — download your free What the Peri? guide → www.kirstencookecoaching.com/free-guide

Come say hi 🌸 Follow along on Instagram and Facebook @kirstencookecoaching — I'd love to hear what resonated with you.

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Research referenced:

• Global Consensus Position Statement on the Use of Testosterone Therapy for Women (2019)
• Davis SR et al. (2015). Testosterone in Women — The Clinical Significance. Lancet Diabetes & Endocrinology
• Australasian Menopause Society — testosterone position statement

This podcast is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare practitioner for personal medical decisions. If you're experiencing a mental health crisis, please contact Lifeline on 13 11 14 (Australia).

Transcript

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I saw five different women's health specialists. Not one of them told me the same thing. Not one of them explained what my hormones were actually doing. They just handed me things: a gel, a script, a shrug. Some of it even made me feel worse than before I started. So I went and learned for myself. And once I understood it, everything changed. This is what I wish someone had told me. Welcome to What the Perry. I'm your host Kirsten Cook, personal trainer, menopause coach, and a woman living it right alongside you. This is the podcast for women navigating perimenopause and menopause. The change you didn't ask for, but the conversations you need. Let's get into it. Last week I told you I'd spent years seeing specialists trying to get answers. Today I want to give you a bit more of that story because I think it will help you understand exactly why this episode matters so much. Over the past several years, I've seen five different practitioners who describe themselves as women's health specialists. Five. And here is what I can tell you with absolute certainty. Not one of them told me the same thing. The first prescribed me estrogen gel without reviewing a single blood test and told me I could increase the dose from one pump all the way to four within the first month or two. She said it was perfectly safe. She also told me I didn't need progesterone because I'd had a hysterectomy. I still have my ovaries, and that's a story for another episode, but it means I'm very much still in perimenopause. And then she sent me on my way with no follow-up booked. Now I knew enough by that point to know that progesterone does far more than protect the uterine lining. It has receptors throughout your entire body. It's essential for sleep. It calms the nervous system. The idea that I didn't need it because I no longer had a uterus didn't sit right with me at all, especially given horrible sleep was one of my biggest symptoms. So I didn't follow her protocol. The second doctor told me the maximum dose was one pump, not four, and that I should only increase every three months under supervision. Direct contradiction. Different doctor, same credential, completely different advice. Both of them dismissed my questions about testosterone completely, despite the fact that I had zero energy, zero libido, could not build or maintain muscle no matter how hard I tried, and was experiencing low mood every single day. Testosterone was not up for discussion. The third doctor gave me both estrogen and progesterone, which felt like progress, but put me straight onto the highest dose of progesterone from day one. Every night I took it, I felt horribly nauseous. All night, I'd wake up the next morning still nauseo, still groggy and barely able to function for work. When I went back and told her, she looked at me and said she had never seen that reaction before, that it was very unusual. She made me feel like I was imagining it, like I was crazy. I knew my body and I knew it was making me feel worse. So if she wasn't going to help me, then my only immediate choice was to stop taking the medication. The fourth doctor didn't want to prescribe estrogen at all, despite my levels being low and my symptom list being extensive, because she worked under a theory that it's the balance of estrogen to progesterone that matters, not the levels themselves. Now there is some truth in that, but she was using it to discount other factors entirely. Again, there was no willingness to discuss testosterone, and it was a come back in three months. I sat in that appointment and I burst into tears. Genuinely distraught. I was at the time at what I thought was my lowest point. And her solution, send me away for three months. What I did not share in episode one is that there came a point, not long before I started this podcast, where I was barely holding on. The brain fog was so severe I genuinely thought I was going to have to give up my work. The fatigue was bone crushing. I was surrounded by people all day, in my home, in my studio with my clients, and I'd never felt more alone or more defeated in my life. The person I had been, outgoing, energetic, ambitious, genuinely happy, seemed to have completely disappeared. And I didn't know if she was coming back. I want to say that clearly because I know there are women listening to this right now who are in that place, who are lying awake at 3 a.m. wondering how much longer they can keep going, who are doing everything they're supposed to do, seeing doctors, trying treatments, pushing through, and still feeling like they're getting worse. If that is you, I see you. You are not broken, and it does get better. I'm proof of that. What eventually changed was finding a practitioner who was willing to actually listen, who agreed without hesitation that I needed testosterone. He told me that just because I hadn't done well with one form of estrogen didn't mean that all forms were wrong for me. Who validated what I had suspected for years, that my body was not the problem, the problem was the care I had been receiving. I'm not fully through the other side yet. This is not a tidy recovery story with a bow on the end. But for the first time in years, I feel like I'm moving forward, and I know enough now to understand exactly why the road was so hard. Part of that reason, a big part of it, is that most of the practitioners I saw did not have a deep enough understanding of how these hormones actually work. And that is what we're covering today. Welcome back to What the Perry. I'm Kirsten Cook. Last week we covered the 34 symptoms of perimenopause, and then some. This week we're going to go one level deeper because I believe that once you understand how these hormones actually work, everything else starts to make sense. The symptoms, the treatments, why some worked and some didn't, why your doctor said one thing and then the next one said something completely different. This is the episode I needed before I walked into any of those appointments. And this is the episode I am giving you now in plain English with no jargon, no agenda, and no medical textbook required. We're talking about three hormones today estrogen, progesterone, and testosterone, the three pillars of female hormonal health. And by the end of this episode, you'll understand what each one does, what happens when they start to shift, and what tests to ask your doctor for. Let's start with the big one. Estrogen. Most women know the word. Far fewer know what it actually does, or that there is not just one type, there are three. Estradiol, also written as E2, is the most potent form. This is your dominant estrogen during your reproductive years, and it's the one that drives most of the perimenopausal story. Estriol, E3, becomes dominant during pregnancy, and estrone, E1, is the form that remains after menopause, produced mainly in fat tissue rather than the ovaries. When your doctor prescribes estrogen, like the estradiol gel I was offered repeatedly, it is almost always estradiol they're working with. And understanding which form you are taking and how it is delivered matters enormously. More on that in a moment. So what does estrogen actually do? It regulates your body temperature, which is why when it drops your internal thermostat goes haywire and you wake up drenched. It maintains bone density, which is why the risk of osteoporosis rises sharply after menopause. It supports cardiovascular health, protecting the lining of your blood vessels and keeping cholesterol in a healthy balance. It maintains the health of your vaginal and urinary tissue. It supports your brain, influencing serotonin, dopamine, and the neurotransmitters that regulate mood, memory, and sleep. It plays a role in your gut, your skin, your hair, your eyes, your joints, and as we discussed last week, your nose, your mouth, and your ears. Estrogen receptors are everywhere, which is why when estrogen starts fluctuating in perimenopause, not just declining but spiking and crashing erratically, the effects are felt everywhere simultaneously. Here's the thing about estrogen in perimenopause that trips people up, including, as I discovered, some of the practitioners I saw. In perimenopause, estrogen does not simply go down in a nice straight line. It fluctuates and wildly. Some months it spikes higher than it ever has in your adult life, other months it crashes, and that volatility, more than the actual level, is what drives so many of the symptoms. This is also why a blood test taken on the wrong day of your cycle can give a completely misleading picture of where your estrogen actually is. One reading does not tell the story. And this brings me to something that matters for anyone who has been prescribed estrogen therapy and had a reaction to it, or felt worse rather than better. Just because one form of estrogen didn't work for you does not mean estrogen therapy is wrong for you. There are different forms gels, patches, sprays, creams, lozenges, implants. There are different doses. There are different delivery systems that affect how the hormone is absorbed and metabolized. The fact that I was offered the same type of estrogen gel by four different practitioners when I clearly stated it hadn't worked for me, is not a reflection of what estrogen therapy can do. It's a reflection of the limited knowledge those practitioners had about the full range of options available. Progesterone is the hormone I wish more women knew about, and I wish more doctors truly understood. Progesterone is made by the corpus luteum, the structure that forms in the ovary after an egg is released, which means that as ovulation becomes less regular in perimenopause, progesterone production drops, often before estrogen does. And this, I believe, explains why for so many women, the very first signs of perimenopause are not hot flashes. They're worsening PMS, increasing anxiety, disrupted sleep, a feeling that emotional regulation has gone slightly offline. It certainly was for me. Years before I would have described myself as symptomatic, something had shifted. I just didn't know what it was. So what does progesterone do? It's your calming sleep-promoting hormone. It works via GABA receptors in the brain, the same pathway that anti-anxiety medications work on. So when progesterone is falling, the GABA pathway is less supported. Anxiety increases, sleep becomes disrupted, and the nervous system becomes less regulated. It balances estrogen, preventing the effects of estrogen dominance that can occur when estrogen is high relative to progesterone. It supports thyroid function. It has anti-inflammatory effects, and yes, it protects the lining of the uterus. Here is where I need to be direct about something that cost me a great deal of confusion and suffering. Multiple practitioners told me I did not need progesterone because I had had a hysterectomy. Their reasoning, progesterone's job is to protect the uterine lighting, and without a uterus, that job is irrelevant. But here is what those practitioners either did not know or did not communicate. Progesterone receptors exist throughout the entire body, in the brain, the bones, the cardiovascular system, the nervous system. Progesterone has systemic effects that are completely independent of whether you have a uterus or not. The sleep benefits alone, which are documented and well evidenced, are reason enough for many women without a uterus to use progesterone. I knew this and I kept raising it, and I kept being dismissed, which is why I want you to know it too, so that you can advocate for yourself in that conversation. Now, there is something important to understand about the difference between progesterone and progestins, because they are not the same thing, and this distinction matters enormously. Micronized progesterone, also known by the brand name prometrium or utragestin, is bioidentical. It is chemically identical to the progesterone your body produces. It has the sleep-promoting, calming effects I described. It carries a better safety profile than synthetic alternatives. Synthetic progesterons, like the madroxy progesterone acetate used in some combined pill formulations and in certain HRT protocols, are not the same. They behave differently in the body. They do not carry the same sleep and mood benefits, and they are associated with the increased breast cancer risk found in the 2002 Women's Health Initiative study, which we'll cover in full detail in episode three. I was prescribed prometrium, micronized progesterone, and I became violently nauseous. Every night, all night, into the next day, I could barely function. When I reported this, I was told it had never happened before, that it was very unusual, that I was probably imagining it or it would pass. What I now know, and what I wish someone had told me then, is that while prometrian is the right choice for many women, some women genuinely do not tolerate oral micronized progesterone well. The nausea is real, the grogginess is real, and for those women there are alternatives, including different delivery methods, different formulations, and compounded progesterone creams. The answer is not to push through or to question your sanity. The answer is to find a practitioner who will explore the alternatives with you. And then there is testosterone, the hormone that every single practitioner I saw for two years refused to discuss with me. Let me say this clearly, because it still astonishes me. Testosterone is one of the three most important hormones in a woman's body. Women produce testosterone in the ovaries and the adrenal glands throughout their lives. It declines gradually from the late 20s onwards, long before estrogen does, and by menopause, levels are roughly half what they were at their peak. So, what does testosterone do in women? Libido. That's the obvious one. And yes, it is real and significant. But testosterone also drives motivation and drive. Energy, cognitive sharpness, that sense of mental clarity and focus, muscle mass and muscle maintenance, which is why even with consistent strength training and high protein intake, I could not build or maintain muscle for two years. Bone density, a general sense of vitality and well-being that is very difficult to describe when you have it, and devastatingly apparent when it's gone. When I described these symptoms to my practitioners, zero energy, inability to build muscle despite training correctly, no libido, low mood, I was either dismissed outright or told my testosterone levels would be checked in a future appointment. That future appointment never seemed to come, and when it did, the results were almost always presented as within normal range, without any acknowledgement that normal range for women's testosterone is barely a range at all, and that many women feel significantly better with levels in the upper quarter of that range. Now here's the global picture, and I want you to understand how significant this is. Government-approved testosterone therapy, specifically formulated for women, is not currently available in most countries worldwide. In most of Europe, women who are prescribed testosterone receive a microdose of a male formulation, used off label. The treatment exists. The evidence supports it, the product does not. Think about that. One of the three most important hormones in a woman's body, and in most of the world, there is no approved female formulation. Women are either prescribed a male testosterone product at a fraction of the dose, which can work but requires a practitioner to really know what they're doing, or they go without. Australia is actually ahead of the curve here, which is not something I often get to say about our approach to women's hormonal health. In 2020, Australia became the first country in the world to have a government-approved testosterone cream specifically formulated for women. It's called Androphem. It is a 1% testosterone cream applied to the skin, and it's a genuine step forward. However, there is a catch, and it is a significant one. In Australia, Androphem is approved specifically for the treatment of a condition called HSDD, hypoactive sexual desire disorder. This is a diagnosable condition characterized by persistently low sexual desire that causes significant personal distress. And here is the problem. By the time a woman meets the diagnostic threshold for HSDD, by the time her libido has been so low and non-existent for long enough that it has caused enough distress and has been formally assessed, her testosterone levels may have been low for years. The fatigue, the muscle loss, the brain fog, the loss of vitality, all of which can also be driven by low testosterone, are not the qualifying conditions. She has to be distressed enough about her libido specifically, for long enough, formally assessed. Does that strike you as an adequate response to what is happening in a woman's body? I don't think so. Now let me put this into stark perspective because I want you to feel the full weight of this disparity. A man in Australia who is struggling with erectile dysfunction can open up his phone right now, complete an online consultation in minutes, and have a Viagra prescription sent directly to his phone for around $30. No waiting list, no specialist referral, no years of suffering while the condition is deemed not serious enough. An entire private telehealth industry has been built efficiently, lucratively, and with very little friction around the premise that men's sexual function matters and deserves fast accessible treatment. Men experiencing low testosterone can access specialized telehealth clinics that take them from initial consultation to treatment in as little as one to two weeks. Now, a woman with debilitating low testosterone affecting not just her libido but her energy, her muscle mass, her cognitive function, her mood, her sense of self spends years trying to have the conversation with a practitioner who will take her seriously. When she finally does find someone, she's told that the only approved indication for female testosterone therapy is a formally diagnosed condition called HSDD, that the low libido must have been present for long enough, must cause significant personal distress, must be formally assessed, and even then the treatment is only approved for postmenopausal women, not perimenopausal women, who may have been suffering for years before they reach that threshold. Government approved testosterone therapy for women is not currently available worldwide, presumably because of the lack of long-term efficacy and safety data and the barriers to product development and approval. Men's sexual dysfunction, a $30 phone consultation and same-week treatment. Women's sexual dysfunction? Years of suffering, multiple specialist appointments, a formal diagnosis, and then maybe a treatment, depending on where in the world you live. I'm not saying that men's health does not matter. I'm saying that the disparity in how urgently and how resourcefully the medical system responds to men's sexual health versus women's sexual health tells you everything you need to know about who this system was built for. And it's not us. An estimated 1.34 million Australian midlife women are currently experiencing symptoms of HSDD. That number does not include the women suffering low testosterone in other ways, the exhaustion, the muscle loss, the flat mood, who do not meet the specific sexual desire criteria for the diagnosis. The gap is enormous, and closing it requires practitioners who are willing to look at the full picture of what testosterone deficiency actually looks like in women, not just the one symptom that qualifies them for the approved treatment. My current practitioner, the fifth one, the one who finally listened, agreed to discuss testosterone without me having to fight for it. And for the first time, I'm actually on a protocol that addresses all three hormones. It is early days, but it's the first time in years that I feel like we are looking at the full picture. Before I take you to the blood tests, which is where this episode gets practically useful, I want to talk briefly about what I call the hormonal hierarchy. Because estrogen, progesterone, and testosterone do not operate in isolation. They are part of a broader hormonal system, and what is happening in the rest of the system matters enormously. Cortisol comes first. Your primary stress hormone takes physiological priority over sex hormones. Your body will always prioritize survival over reproduction. Which is what cortisol essentially signals. Chronic stress, and perimenopause is itself a physiological stressor on top of whatever else is in your life, directly impacts your ability to produce progesterone. The raw materials used to make cortisol and progesterone overlap. When the body is under chronic stress, it diverts those materials towards cortisol. This is sometimes called the pregnenolone steel, and it is one of the reasons why stress management is not optimal in perimenopause. It's biological. Thyroid hormones interact closely with estrogen and with the entire reproductive hormonal system. Thyroid dysfunction, particularly Hashimoto's thyroiditis, is significantly more common in women in their 40s and produces fatigue, weight gain, brain fog, hair loss, mood changes, and poor sleep, exactly like perimenopause, which is why ruling out thyroid dysfunction is always one of the first steps. I'll cover this in detail in the blood test section. Insulin resistance increases through the menopausal transition. As estrogen declines, cells become less responsive to insulin, meaning glucose is less efficiently used and more likely stored, particularly as visceral fat around the abdomen. This is why dietary changes that make no difference in your 30s suddenly matter enormously in your 40s and 50s. The hormonal picture in perimenopause, it's not just about three hormones going down. It is a systemic shift across your entire endocrine system. And every practitioner who looks at only one part of the picture is missing most of the story. Right, let's get practical, because one of the most common things I hear from women is, I don't know what to ask for when I go to my doctor. So here is exactly what to ask for. Take a photo of this section, write it in your phone, bring it to your next appointment. First, the foundational panel. These are the tests that rule out conditions that mimic perimenopause that every woman in this age group should have regardless of symptoms. The foundational panel. Full blood count checks for anemia which causes fatigue, hair loss, and brain fog, and is extremely common in women in their 40s. Iron studies, specifically serumferritin. A ferritin below 30 micrograms per liter causes fatigue and hair loss, even when your hemoglobin is technically normal. Most standard blood tests will not flag this as low. You'll need to look at the actual number. Thyroid panel. TSH, free T3, free T4. TSH alone is not sufficient. A TSH can be within range while free T3 is low, and low T3 causes fatigue, weight gain, and brain fog. Ask for the full panel. Vitamin D. Vitamin D deficiency is extraordinarily common in Australia despite our climate, because most of us spend our working days indoors. Vitamin D deficiency causes fatigue, low mood, musculoskeletal pain, and immune dysfunction. Target level is 75 to 100 nanomoles per liter. If your GP says you are fine at 50, push back. Vitamin B12 deficiency causes neurological symptoms, including brain fog, tingling, and fatigue, and is more common than most people realize, particularly in women who have used the oral contraceptive pill long term. Fasting glucose and insulin or HBA1C assesses insulin resistance, which as I mentioned increases significantly through the menopause transition. Lipid panel, total cholesterol, HDL, LDL, triglycerides, your cardiovascular risk baseline, which matters enormously given what we know about estrogen's role in heart health. The hormone panel, this is where it gets more nuanced because hormone testing in perimenopause has significant limitations that your doctor may not explain to you. FSH, follicle stimulating hormone. This is the test most GPs use to check for menopause. An elevated FSH above 30 suggests menopause may have occurred. But, and this is critical, FSH fluctuates wildly in perimenopause. One elevated reading does not confirm menopause. One normal reading does not rule out perimenopause. This test is unreliable as a standalone diagnostic in the transition years. Estradiol E2. Ideally tested on day two or three of your cycle if you still have periods. Again, one reading tells you where you are on one specific day. It does not tell you the full fluctuation story. Progesterone, ideally tested on day 21 of your cycle, the midpoint of the luteal phase, to assess whether ovulation is actually occurring and what your progesterone response looks like. Testosterone. Total testosterone and, if possible, free testosterone and SHBG, sex hormone binding globulin. SHBG is the protein that binds to testosterone and makes it unavailable. High SHBG can mean your total testosterone looks adequate on paper while your free active testosterone is actually very low. This is why total testosterone alone can be misleading. AMH, any malarian hormone, reflects your ovarian reserve, how many eggs you have left, declining in perimenopause. Not essential but useful context, particularly if you're trying to understand where you are in the transition. Here's the most important thing I want you to take from this section. Results within normal range do not mean optimal for you. Normal ranges are based on population averages. You are not an average. You are a specific woman with a specific symptom picture, a specific history, and a specific body. A result at the bottom of normal and a result at the top of normal are not the same thing, even if they're both technically fine. Any practitioner who responds to your symptoms with your bloods are normal without looking at where within that range your results sit and without cross-referencing them with how you actually feel is not doing their job adequately. Request copies of all your results, you're entitled to them. Track them over time. Trends matter more than single readings. As always, the research behind today's content is linked in the show notes. I also want to point you to Susan Davis and colleagues at Monash University, whose work on testosterone in women has been foundational, including some of the research that supported the Australian approval of Androphem. Here's what I want you to take from today. Your hormones are not just three things declining at menopause. They are a complex interconnected system that's been supporting every function in your body your entire adult life. When they shift, and they do shift in perimenopause, unpredictably and sometimes dramatically, the effects are felt everywhere, in your brain, your bones, your heart, your skin, your sleep, your mood, your muscle, and your sense of self. Understanding even the basics of what estrogen, progesterone, and testosterone do, and why they matter, changes the conversation you can have with your doctor. It means you can ask better questions. It means you can push back when something doesn't feel right. It means you can recognize when the care you are receiving is not adequate, and keep looking until you find someone who can actually help you. I spent years not having that knowledge, and it costs me. I don't want it to cost you the same. Your action for this week? Book a blood test. Take the list from today's show notes or screenshot the episode summary and ask your GP for the full panel, not just FSH, not just estrogen, the full picture. Next week, we are tackling the topic that causes more fear and more confusion than almost anything else in this space. HRT. What does the research actually say? What was wrong with the study that scared an entire generation of women off hormone therapy? And how do you make an informed decision? It's gonna be a good one. If today's episode helped you, please subscribe, leave a review, and share this with a woman who you know is navigating this. Every review makes a real difference in helping What the Perry reach the women who need it most. Thanks for being here. Everything I've mentioned today is referenced in the show notes along with all the links. And you can find me at KirstencookCoaching.com. Just a reminder, though, this is education, not medical advice. So take these conversations to a practitioner who will actually listen to you. Thank you so much for being here and for listening to the What the Perry podcast. The change you didn't ask for, the conversations you need to do.