Book in one sentence: A UK nutritional therapist walks women through the four hormones wrecking their health after 40, and shows how food and lifestyle can actually fix them.
- What Is It’s Not You, It’s Your Hormones! About?
- Why Am I Gaining Weight When Nothing Has Changed?
- What Is the Happy Hormone Code?
- What Does “Normal” Lab Work Actually Miss?
- Is It’s Not You, It’s Your Hormones! Worth Reading?
- Books Like It’s Not You, It’s Your Hormones!
What Is It’s Not You, It’s Your Hormones! About?
Picture this: you’re standing at the kitchen sink, too depleted to think, and your seven-year-old comes in to show you a drawing she made at school. You snap at her. Her face falls. She says, “Why are you always so grumpy, Mummy?” That moment happened to Nicki Williams in January 2007. She was 42, exhausted, gaining weight around her middle despite trying every diet, and had just left her GP’s office holding a Prozac prescription she didn’t want.
Williams sat in her car and cried. Then she called her father (also a doctor, one who had long since moved toward functional medicine) and he said: “Don’t worry, Nick. It’ll be your hormones.” That conversation sent her back to school, through a four-year qualification at the Institute of Optimum Nutrition, and eventually into a clinical practice built around the population she had become: women over 40 who feel terrible and keep being told their bloodwork is fine.
It’s Not You, It’s Your Hormones! is the book that came out of that journey. Williams is not an academic, and she writes like a practitioner, not a researcher. What she offers is a clear, accessible framework for understanding why perimenopause-era symptoms (fatigue, abdominal weight gain, brain fog, mood swings, broken sleep) happen at a physiological level, and what food and lifestyle changes can do about them. The UK origin means NHS references and British supplement brands appear throughout, but the underlying physiology translates cleanly anywhere.
Why Am I Gaining Weight When Nothing Has Changed?
That question drives most of the women who pick up this book. They haven’t changed what they eat. They’re not sedentary. They’re doing all the things that used to work, and the scale is still creeping up, specifically around the middle, in a way it never used to.
Williams’s answer centers on cortisol and insulin working together against you. Cortisol, the stress hormone, has a direct effect on abdominal fat storage: abdominal fat contains four times more cortisol receptors than fat anywhere else in the body. When cortisol is chronically elevated (from any form of stress, including poor sleep, refined carbohydrates, or skipped meals), it mobilizes blood glucose. That glucose spike triggers insulin. Insulin is the fat-storage signal, and with blood sugar elevated, it’s chronically activated regardless of how little you’re eating.
“Not only do we have four times more cortisol receptors in our abdominal fat than any other part of the body, but cortisol also stimulates appetite — sugar and carbs are vital when you need energy to run from that lion.”
The practical consequence is brutal: calorie restriction often makes this worse. A severe cut signals famine to the brain, which triggers more cortisol, which slows metabolism and breaks down muscle for glucose, which produces powerful cravings for sugar and refined carbohydrates. Williams draws on Zoe Harcombe’s work to note that 98% of people either fail to lose weight on a calorie-controlled diet or regain what they lost. The mechanism itself produces those outcomes.
The loop she describes is also behind the 3am wake-up and the afternoon crash. Blood sugar drops overnight, cortisol surges to correct it, and you’re wide awake. The morning exhaustion that follows sends you to coffee and carbohydrates, blood sugar spikes and crashes again, and the cycle restarts. Understanding that this is a physiological cascade, not a willpower failure, is the orientation shift the book is built around.
What Is the Happy Hormone Code?
Williams organizes her intervention into four steps: Eat, Rest, Cleanse, Move. Each maps to a specific hormonal lever. The whole system is built around what she calls the “Feisty Four”: cortisol, insulin, thyroid, and estrogen/progesterone. These four hormones interact so tightly that dysfunction in one tends to cascade into the others.
A few things worth knowing from each step:
Eat reframes food as hormonal information rather than calories. The practical targets are protein at every meal, low-glycemic-load carbohydrates, cruciferous vegetables (which contain indole-3-carbinol to support estrogen metabolism through the liver), healthy fats, and 35 grams of fiber daily. Ground flaxseeds get specific attention: two tablespoons a day, because flaxseeds contain lignans at roughly 100 times the concentration of any other food source, and lignans bind excess estrogen for elimination via the gut. A minimum 12-hour overnight fast is also recommended for insulin management.
Rest addresses cortisol directly. Williams is clear that stress management isn’t optional, it’s the foundational intervention. Consistent sleep before 11pm, diaphragmatic breathing (five-count rhythm, ten repetitions), and screens off one hour before bed are her baseline. Adaptogenic herbs like ashwagandha and rhodiola get a mention as cortisol modulators, and magnesium glycinate at bedtime comes up repeatedly as a first-line supplement because magnesium is rapidly depleted by stress and supports both cortisol regulation and sleep.
Cleanse focuses on xenoestrogens, the environmental chemicals from plastics, pesticides, and personal care products that mimic estrogen in the body. Williams recommends switching to glass and stainless steel where possible, choosing organic produce for high-pesticide items, and supporting the liver and gut as the main clearance routes for excess estrogen. The cruciferous vegetable recommendation reappears here.
Move reframes the exercise question for cortisol-depleted women. More cardio is not better. Williams advocates 30-minute daily walks, brief HIIT sessions (15 minutes, two or three times a week, because short HIIT raises growth hormone and improves insulin sensitivity without adding significant cortisol load), resistance training, and yoga or Pilates for their cortisol-lowering effects specifically.
One of the more useful distinctions in the book is Williams’s separation of estrogen dominance from low estrogen. These are two different perimenopausal states that require different responses. Estrogen dominance (too much estrogen relative to declining progesterone, common from the mid-30s onward) produces heavy or painful periods, breast tenderness, PMS, bloating, and conditions like fibroids. Low estrogen (the later perimenopausal and menopausal state) produces hot flushes, night sweats, dry skin, and memory changes. Using phytoestrogen support for the dominance phase can worsen it. The framework to tell them apart is one of the book’s more distinctive contributions.
What Does “Normal” Lab Work Actually Miss?
A significant portion of Williams’s readership has already been to their GP, had blood drawn, been told everything looks fine, and left no closer to understanding why they feel awful. The testing chapter is written for them.
Williams draws a sharp line between “normal” (anywhere within a reference range) and “optimal” (in the range where symptoms actually resolve). The thyroid example is the clearest illustration. The NHS upper limit for TSH is 5.0 mU/L. Many integrative practitioners treat 2.5 mU/L as the functional upper limit. A result of 4.2 is entirely “normal” by conventional standards and may prompt nothing further, while a patient at that level could be functionally hypothyroid.
“There is often a huge difference between someone with optimal TSH and someone with a level that is just within range. It will most often show up in their symptoms. If you ask me, I’d be wanting OPTIMAL levels not ‘normal’ levels.”
Standard thyroid panels measure only TSH, which is the pituitary’s signal to produce thyroid hormone, not whether the body is converting that hormone into its active form (T3) or whether the cells can receive it. Williams recommends requesting TSH, free T4, free T3, Reverse T3, and TPO antibodies (the last one for Hashimoto’s autoimmune thyroiditis, which she notes accounts for roughly 80% of hypothyroid cases). She also introduces the Barnes Basal Temperature Test, six consecutive mornings of underarm temperature readings before getting up, as a low-cost screen: consistent readings below 36.6°C suggest low thyroid function even with normal labs.
For adrenal function, she recommends saliva cortisol testing over serum testing, because saliva captures cortisol at multiple points through the day (including the critical morning cortisol awakening response) rather than a single snapshot. For sex hormones, she specifies timing: days 19-20 of the cycle, when progesterone should be at its peak and the estrogen-to-progesterone ratio is most informative. A woman tested on day 5 or day 28 gets a picture that tells a very different story.
Is It’s Not You, It’s Your Hormones! Worth Reading?
Read this if you’re between roughly 35 and 55, experiencing the cluster of symptoms Williams describes (fatigue that doesn’t resolve with sleep, abdominal weight gain, worsening PMS or cycle changes, mood instability, brain fog), and especially if you’ve had normal labs and been told there’s nothing wrong. Also useful if you’re a health coach or practitioner working with this population and want a clear client-education framework.
Skip it if you want a heavily cited research text or if you’re primarily post-menopausal and focused on HRT decisions. The HRT chapter is balanced and honest about the limits of Williams’s expertise in that area, but it’s thin coverage for someone who needs it to be the main event.
One caveat: the book was published in 2017, the research base for several claims (especially around HIIT for women over 40 and some of the adrenal fatigue framing) has evolved since then, and the UK-specific medical references require translation for anyone outside the NHS. Williams does not always distinguish clearly between interventions with strong evidence and those with more preliminary or clinical-observation-only support. Take the supplement protocols as a starting point for a conversation with a practitioner, not a prescription.
Books Like It’s Not You, It’s Your Hormones!
| Book | Author | Best For |
|---|---|---|
| Happy Hormones | Angelique Vermeulen | Women who want a broader hormonal overview beyond perimenopause |
| The Hormone Shift | Tasneem Bhatia | Deeper clinical detail with a heavier research base |
| Hormone Intelligence | Aviva Romm | Integrative MD perspective with stronger evidence citations |
| The Perimenopause Solution | Dr. Shahzadi Harper | UK-based GP who covers HRT and lifestyle together |
| Is It Me or My Hormones? | Marcelle Pick | Similar audience, more emphasis on the emotional and relational side |