Functional Medicine for Women's Health

I integrate functional medicine into my gynaecology practice because, after years of treating women with conditions such as PCOS, endometriosis, and difficult perimenopause, I kept encountering the same problem: conventional treatment would address the immediate symptoms, but something was still missing. Women would come back and say they felt better in one respect but worse in another, or that their blood results were “normal” yet they felt anything but. Functional medicine gives me the framework to ask the deeper question — why is this happening? — and to act on the answer.

This article explains what a functional medicine consultation in my clinic actually involves, who benefits most, the specific investigations I use, and where the evidence stands. My goal is to give you a transparent, clinician-level view so you can decide whether this approach is right for you.

What is functional medicine?

Functional medicine is a patient-centred, science-based approach that focuses on identifying and addressing the root causes of disease. The Institute for Functional Medicine has been instrumental in establishing the evidence base for this methodology. Rather than treating symptoms in isolation, functional medicine examines the complex web of interactions in a patient's history, physiology, and lifestyle that can lead to illness.

In the context of women's health, this means going beyond a standard consultation to explore:

• Hormonal balance — understanding the full hormonal picture, including thyroid, adrenal, and reproductive hormones and how they interact
• Gut health — the microbiome plays a key role in oestrogen metabolism, immune function, and inflammation
• Nutritional status — identifying deficiencies in iron, vitamin D, B vitamins, magnesium, and other nutrients critical to women's health
• Chronic inflammation — a common driver of conditions such as endometriosis, PCOS, and autoimmune thyroid disease
• Stress and adrenal function — how chronic stress impacts hormonal health, sleep, and energy levels
• Environmental factors — the role of endocrine disruptors, toxin exposure, and lifestyle factors in hormonal imbalance

Who benefits most from this approach?

In my experience, the women who benefit most from functional medicine fall into a few recognisable patterns. They are women who have a diagnosed condition — PCOS, endometriosis, thyroid disease — that is being treated conventionally but not fully controlled. They are women in perimenopause whose symptoms are multisystem: fatigue, brain fog, weight gain, mood changes, joint pain, and poor sleep all arriving at once. And they are the women who have been thoroughly investigated by their GP, told everything is normal, and yet feel profoundly unwell.

More specifically, functional medicine consultations are particularly valuable for women experiencing:

• Persistent fatigue that does not improve with rest
• Hormonal imbalances such as irregular periods, severe PMS, or difficult perimenopause
• Digestive issues including bloating, IBS-type symptoms, and food sensitivities
• Recurrent infections or autoimmune conditions
• Weight changes that seem resistant to conventional approaches
• Brain fog, low mood, or anxiety without a clear cause
• Skin conditions such as acne, eczema, or hair thinning linked to hormonal factors

Functional medicine uses more comprehensive testing and evaluates optimal ranges rather than just standard reference ranges. This distinction matters: a thyroid-stimulating hormone (TSH) of 3.8 mIU/L is technically within the NHS reference range, but many women feel significantly better with a TSH closer to 1.0–2.0 mIU/L. Identifying these subtleties is where the approach excels.

A typical functional medicine consultation in my clinic

A functional medicine consultation is longer and more in-depth than a standard appointment — typically 60 to 90 minutes for the initial visit. The process follows a structured path that I have refined over years of practice.

Before we meet, I send detailed questionnaires covering your diet, sleep patterns, stress levels, digestive health, energy, menstrual history, and environmental exposures. I review these thoroughly before the appointment, so our time together is spent on dialogue rather than form-filling.

During the consultation itself, I build a health timeline — a chronological map of your health from early life to the present. This might reveal, for instance, that recurrent thrush began after a course of antibiotics five years ago, that your fatigue coincided with a stressful job change, or that your skin and periods deteriorated after stopping the pill. These connections are often invisible in a standard ten-minute GP appointment, but they are clinically meaningful.

The investigations I actually order

One of the most common questions I receive is about testing. Functional medicine is sometimes criticised for ordering expensive tests without clear rationale. I want to be transparent about what I order and why.

Comprehensive hormonal panels: I frequently use the DUTCH test (Dried Urine Test for Comprehensive Hormones), which provides a detailed picture of oestrogen metabolites, progesterone metabolites, androgens, cortisol patterns throughout the day, and melatonin. Unlike a single-point blood draw, the DUTCH test shows how your body is processing hormones — for example, whether oestrogen is being metabolised through favourable or less favourable pathways. This is particularly useful in perimenopause and for women with oestrogen-dominant conditions such as endometriosis and fibroids.

Comprehensive thyroid panel: Standard NHS thyroid testing often includes only TSH and sometimes free T4. I routinely test TSH, free T4, free T3, reverse T3, and thyroid antibodies (anti-TPO and anti-thyroglobulin). This full panel identifies subclinical Hashimoto's thyroiditis, poor T4-to-T3 conversion, and autoimmune thyroid activity that a basic TSH alone would miss entirely.

Gut health markers: When digestive symptoms, immune dysregulation, or hormonal imbalance suggest gut involvement, I may recommend a comprehensive stool analysis. This assesses microbiome composition, markers of inflammation (such as calprotectin and secretory IgA), digestive enzyme function, and the presence of parasites or pathogenic bacteria. The oestrobolome — the collection of gut bacteria that metabolise oestrogen — is particularly relevant to conditions like endometriosis and PCOS.

Nutrient status: I check iron studies (ferritin, serum iron, transferrin saturation), vitamin D, active B12, folate, red blood cell magnesium, zinc, and selenium. Women with heavy periods frequently have ferritin levels that are technically within range but far below optimal. I consider ferritin below 50 µg/L worth addressing, particularly when fatigue and hair thinning are present.

Inflammatory and metabolic markers: High-sensitivity CRP (hs-CRP), homocysteine, fasting insulin, HbA1c, and a full lipid profile help me understand the metabolic and inflammatory landscape. Fasting insulin is particularly valuable in PCOS — a woman can have a normal fasting glucose while her insulin is already significantly elevated, indicating early insulin resistance that standard testing would miss.

What a functional medicine workup looks like in practice

To make this concrete, here is how a functional medicine approach applies to three conditions I see regularly in clinic.

PCOS: A woman in her late twenties came to me with irregular periods, stubborn weight gain around her midsection, acne that had worsened since stopping the combined pill, and fatigue. Her GP blood tests showed mildly elevated testosterone and an ultrasound consistent with polycystic ovaries. Standard management had been metformin and advice to lose weight. In my functional medicine workup, I found significantly elevated fasting insulin despite normal glucose, low vitamin D (28 nmol/L), suboptimal ferritin (22 µg/L), and a cortisol pattern on DUTCH testing showing chronic low-level stress activation. We continued metformin but added myo-inositol (4g daily), optimised her vitamin D, corrected her iron stores, introduced a Mediterranean-pattern diet with specific attention to glycaemic load, and addressed her sleep quality. Over six months, her periods regulated, her acne improved substantially, and her energy transformed. You can read more about lifestyle strategies for PCOS in my PCOS lifestyle blog post.

Endometriosis: Another patient, a woman in her thirties with surgically confirmed stage III endometriosis, was on a progestogen-only pill for disease suppression. Her pain was better but she described persistent bloating, fatigue, and low mood. Her functional workup revealed gut dysbiosis with elevated inflammatory markers on stool analysis, low zinc, and a DUTCH test showing poor oestrogen detoxification through the 4-OH pathway. I kept her on her hormonal treatment — it was working for pain control — but layered in targeted gut restoration, zinc supplementation, cruciferous vegetable support for oestrogen metabolism, and an anti-inflammatory dietary approach. Her bloating improved within weeks and her energy gradually followed. I discuss the broader holistic approach to endometriosis in this dedicated article.

Perimenopause: A woman in her late forties presented with insomnia, anxiety, joint pain, weight gain, and brain fog. She had been told she was “too young for menopause” and her FSH was normal. However, her comprehensive thyroid panel revealed elevated anti-TPO antibodies with a TSH of 3.6 mIU/L — technically normal but contributing to her symptoms. Her DUTCH test confirmed fluctuating progesterone typical of perimenopause, and her vitamin D was low. We started body-identical HRT alongside thyroid monitoring, vitamin D repletion, magnesium glycinate for sleep, and a structured approach to blood sugar regulation. Within three months, she described feeling like herself again. For more on recognising perimenopausal symptoms, see my article on perimenopause in your 40s.

How functional medicine integrates with conventional treatment

I want to be unequivocal: functional medicine does not replace conventional gynaecology. It sits alongside it. I would never suggest a woman with a large ovarian cyst forgo surgery in favour of supplements, or that someone with severe endometriosis stop their hormonal treatment. What I offer is an additional layer of care — one that asks why the problem developed and what we can do to create the best possible environment for healing.

A patient starting HRT for menopause, for example, may see better results when we also address vitamin D deficiency, optimise her magnesium levels for sleep, and support her gut health. A woman with PCOS who is already on metformin might benefit from dietary changes that further improve her insulin sensitivity. The two approaches are genuinely complementary, and in my experience, women who engage with both tend to feel significantly better than those using either alone.

This integration is deliberate. I am a gynaecologist first. I prescribe medication, I refer for surgery, I follow NICE guidelines. Functional medicine gives me an expanded toolkit, not a replacement one.

The evidence base: what functional medicine gets right, and where it is still building

Intellectual honesty matters to me, and I believe patients deserve a candid assessment of the evidence. There are areas where the functional medicine approach is well supported by research: the role of insulin resistance in PCOS and the benefit of dietary intervention is robust; the impact of gut health on systemic inflammation and oestrogen metabolism is increasingly well documented; nutrient deficiencies as contributors to fatigue, mood disturbance, and immune dysfunction have a strong evidence base; and the benefits of anti-inflammatory dietary patterns are supported by multiple systematic reviews.

There are also areas where the evidence is still building. The DUTCH test, while clinically informative, does not yet have the same volume of validation studies as standard serum hormone testing. Some comprehensive stool tests have limited standardisation across laboratories. And certain supplements promoted within functional medicine circles have preliminary but not conclusive evidence for specific gynaecological conditions.

I navigate this by being transparent with my patients about what the evidence shows, what is biologically plausible but not yet proven, and what falls outside my scope. If a test or intervention does not have a clear clinical rationale for you specifically, I will say so. Good medicine requires honesty about the limits of what we know.

Book your functional medicine consultation

If you are interested in taking a deeper, root-cause approach to your health, I would be glad to discuss whether a functional medicine consultation is appropriate for you. Appointments are available at our London clinics. Book your appointment here or contact us to find out more.