I hear this from women all the time: I went to my doctor, they ran some blood tests, and everything came back normal. But I do not feel normal. I feel exhausted. I cannot sleep. I am gaining weight. My mood is all over the place. And I was told there is nothing wrong.
If this is your experience, you are not imagining things, and you are not being dramatic. The problem is often not with you — it is with what was tested, how it was interpreted, and what was left out. Standard blood panels are designed to detect disease. They are not designed to identify the early metabolic, hormonal, and inflammatory shifts that drive the symptoms of perimenopause. And when the wrong markers are tested — or the right markers are interpreted through the wrong lens — women are told they are fine when they are clearly not.
This article is going to explain what standard testing typically misses, what a more comprehensive approach looks like, and what you can do to advocate for yourself.
The Problem with Standard Hormone Testing in Perimenopause
Many women go to their doctor expecting a blood test that will tell them whether they are in perimenopause. The reality is more complicated. During perimenopause, hormone levels fluctuate significantly — not day to day or week to week but by the minute or hours. A single blood draw is a snapshot of one moment in time, and it tells you very little about the broader pattern.
Oestrogen can be high one week and low the next. Progesterone, which is only produced after ovulation, may not even be present if the blood was drawn during an anovulatory cycle. FSH (follicle-stimulating hormone) is sometimes used to diagnose menopause, but during perimenopause it fluctuates so much that a single reading is unreliable. This is why the current standard of care for diagnosing perimenopause is symptom-based rather than lab-based. If you are in your forties, your periods are changing, and you are experiencing characteristic symptoms, you are very likely in perimenopause regardless of what a single blood test shows.
This does not mean testing is useless. It means that for sex hormones specifically, a single serum snapshot has significant limitations. Tracking symptoms and cycle changes over time often gives a more accurate picture of where you are in the transition.
The Thyroid Panel That Is Almost Always Incomplete
If there is one area where standard testing consistently falls short, it is thyroid. Most doctors will order a TSH (thyroid-stimulating hormone) test, and if it comes back within the reference range, the thyroid is considered normal. Some will also order free T4. But this is not the full picture, and for women in perimenopause, it can be deeply misleading.
A comprehensive thyroid assessment should include TSH, free T4, free T3, reverse T3, and thyroid antibodies (TPO and thyroglobulin antibodies). Here is why each one matters. TSH can appear normal even when thyroid function is suboptimal, because TSH can be artificially suppressed by inflammation, chronic stress, or certain medications. Free T4 tells you how much inactive thyroid hormone is circulating, but it does not tell you whether your body is converting it to the active form. Free T3 is the active thyroid hormone — the one your cells actually use. If T3 is low while T4 and TSH are normal, you may have a conversion problem that will not show up on standard testing. Reverse T3 is produced when the body is under stress and effectively blocks the action of T3 — it is a braking mechanism. Elevated reverse T3 can explain ongoing thyroid symptoms even when other markers look normal. And thyroid antibodies identify whether the thyroid condition is autoimmune, which changes both the treatment approach and the long-term outlook.
The overlap between thyroid symptoms and perimenopause symptoms is significant: fatigue, weight gain, brain fog, hair loss, low mood, constipation, feeling cold. Without a full thyroid panel, it is impossible to know whether these symptoms are being driven by hormonal changes, thyroid dysfunction, or both — which is often the case, since perimenopause can actually trigger or worsen autoimmune thyroid disease.
There is another important nuance. Many women are told their thyroid is fine because their results fall within the reference range. But reference ranges are broad averages based on the general population, not optimal ranges. For free T3, for example, most women feel their best when levels are in the upper portion of the range, not simply anywhere within it. Finding a practitioner who understands functional ranges and interprets results in the context of your symptoms is essential.
Insulin: The Marker Most Women Have Never Had Tested
Insulin resistance is one of the most significant metabolic shifts that occurs during and after menopause, and it drives weight gain, energy crashes, increased cardiovascular risk, and cognitive decline. Yet fasting insulin is almost never included in routine blood work.
Standard testing typically includes fasting glucose, and sometimes HbA1c (a marker of average blood sugar over the past three months). These are useful, but they are late-stage markers. By the time fasting glucose or HbA1c is elevated, insulin resistance has often been present for years. Fasting insulin rises long before glucose does, because your body compensates by producing more and more insulin to keep blood sugar in check. Testing fasting insulin allows you to identify insulin resistance early, when it is most responsive to dietary and lifestyle intervention.
If you are experiencing stubborn weight gain (especially around the middle), energy crashes after meals, strong sugar cravings, difficulty losing weight despite consistent effort, or increasing waist circumference, asking for a fasting insulin test is one of the most valuable things you can do. An oral glucose tolerance test with insulin measurements provides even more information about how your body handles glucose in real time.
What Else Gets Missed
Beyond thyroid and insulin, there are several other markers that are frequently left out of standard panels but are highly relevant for women in midlife.
Vitamin D is essential for bone health, immune function, mood, and hormonal balance. Many women in midlife are deficient, particularly those living in less sunny climates. Optimal levels are considered to be between 100 and 150 nmol/L (40-60 ng/mL), which is higher than the minimum reference range many labs use.
Iron studies (not just haemoglobin, but ferritin, transferrin saturation, and serum iron) are important because low ferritin is a common cause of fatigue, hair loss, restless legs, and poor exercise tolerance in women, and it can be missed if only haemoglobin is checked. Ferritin can be low even when haemoglobin is normal.
Vitamin B12 is critical for energy, mood, cognition, and nerve function. Deficiency is more common than many people realise, particularly in women taking certain medications like metformin or proton pump inhibitors. Folate and homocysteine can provide additional insight into methylation status, which affects detoxification, hormone metabolism, and cardiovascular health.
A full lipid panel including ApoB, triglycerides, HDL, LDL, and ideally lipoprotein particle size gives a much better picture of cardiovascular risk than total cholesterol alone. Cardiovascular risk increases significantly after menopause, and understanding your lipid profile in detail is an important part of proactive health management.
Inflammatory markers like high-sensitivity CRP and ESR can indicate whether systemic inflammation is part of your picture. And markers like SHBG (sex hormone-binding globulin) can provide insight into the balance between your hormones, particularly the relationship between oestrogen, testosterone, and insulin.
How to Advocate for Yourself
If you are reading this and recognising that your testing has been incomplete, here are some things you can do.
Start by tracking your symptoms. Write down what you are experiencing, when it happens, and how it affects your daily life. This gives you concrete information to bring to any conversation with a practitioner and makes it harder for your concerns to be dismissed.
Ask specific questions. Rather than asking for a general hormone check, ask for the specific markers you want tested. Request a full thyroid panel including free T3, reverse T3, and antibodies. Ask for fasting insulin. Ask for ferritin, vitamin D, and B12. You can frame it as wanting to take a proactive approach to your health and being willing to pay for additional testing if necessary.
Understand that reference ranges are not the same as optimal ranges. If you are told everything is normal but you do not feel well, ask what your actual numbers are and where they fall within the range. A result at the very bottom of the reference range is technically normal, but it may not be optimal for you.
Consider working with a practitioner who takes a functional approach. Functional health practitioners are trained to look at the full picture, to use comprehensive panels, and to interpret results through the lens of optimal function rather than disease detection. This does not replace your GP — it complements them.
Remember that testing is a tool, not a destination. The goal of testing is to inform a strategy. The most useful approach is one that combines comprehensive lab data with a thorough understanding of your symptoms, your history, and your goals, and then builds a personalised plan from that foundation.
Knowledge Is Power
The reason I am so passionate about this topic is that I have seen what happens when women finally get the full picture. When a woman who has been told for years that everything is normal finally discovers that her free T3 is low, her insulin is elevated, her ferritin is depleted, and her vitamin D is insufficient — and suddenly her symptoms make sense. That moment of clarity is powerful. It is the difference between feeling confused and dismissed, and feeling informed and equipped.
You deserve testing that matches the complexity of what your body is going through. You deserve results that are interpreted with nuance and intelligence. And you deserve a practitioner who listens to your experience and uses data to support a strategy that is built around you.