What to actually test in perimenopause.

Perilune is not a clinical service. This information is for educational purposes. Discuss all testing decisions with your GP or a healthcare professional who knows your history.

Hormone Zoomer (Urinary Hormones)

Ask for: DUTCH test or urinary hormone panel

A single blood draw gives you ONE number at ONE moment. In perimenopause your hormones are wildly fluctuating -- a snapshot is meaningless. Urinary hormone testing maps the pattern, not just the moment.

ApoB (Apolipoprotein B)

Optimal: under 80 mg/dL

Estrogen is cardioprotective. It keeps artery walls flexible, reduces inflammation, and regulates cholesterol particle size. As estrogen drops in perimenopause, cardiovascular risk rises sharply. Your standard cholesterol panel estimates particle count -- and it is wrong up to 50% of the time. ApoB directly counts every atherogenic particle that can lodge in your artery walls.

Vitamin D (25-OH)

Optimal: 50-80 ng/mL. Most perimenopausal women test at 18-30.

Low vitamin D in perimenopause means accelerated bone loss (osteoporosis starts now, not at 60), worse hot flushes, higher anxiety, deeper depression, worse insulin resistance, poor sleep, increased joint pain, and a weakened immune system. Vitamin D also directly supports progesterone production -- the hormone that crashes first in perimenopause, the one that keeps you calm, helps you sleep, and stops the rage.

HbA1c

Optimal: 4.8-5.3%. The "normal" range goes up to 5.6 -- that is already metabolic dysfunction.

Estrogen is one of your body's primary insulin sensitizers. As it fluctuates and drops in perimenopause, your cells become more insulin resistant -- automatically, without you changing a single thing about your diet. The same foods you ate at 35 with no issues are now spiking your blood sugar, storing visceral fat, and keeping you in a cycle of crashes and cravings. HbA1c shows you the three-month picture: the post-meal spikes, the reason for brain fog after lunch, the 3pm crash, the belly that will not budge.

Ferritin

Optimal: 50-100 ng/mL

Hair loss in perimenopause is frequently blamed on hormones when the actual cause is low ferritin. Under 30 ng/mL and your hair starts falling out. Under 50 and your energy, cognition, exercise tolerance, and sleep quality tank. You get restless legs, breathlessness on stairs, and anxiety you mistake for perimenopause. Low ferritin also amplifies every perimenopausal symptom -- fatigue, brain fog, mood instability. You can be treating your hormones and completely missing the foundation.

SHBG (Sex Hormone Binding Globulin)

Ask for SHBG alongside your hormone panel -- it is the missing context

SHBG explains why two women with identical hormone levels on paper can have completely opposite symptoms. High SHBG (common with birth control history, low-calorie dieting, or high stress) means your already-declining estrogen and testosterone get bound up even more -- barely reaching your cells. That is your disappearing libido, muscle wasting, skin drying out, motivation gone, even though your levels look fine. Low SHBG (common with insulin resistance and weight gain) means too much free testosterone running loose -- chin hair, thinning scalp hair, acne at 42, rage, heavy bleeding.

RBC Magnesium

Optimal: 5.6-6.8 mg/dL on RBC magnesium (not serum -- serum is almost always normal even when you are deficient)

Estrogen helps you retain magnesium. As estrogen drops, you start excreting magnesium at an accelerated rate -- losing it faster and needing more of it because your nervous system is already dysregulated. Magnesium is required for sleep, muscle relaxation, stress response, blood sugar regulation, progesterone production, heart rhythm, and calming the nervous system. Every symptom you are attributing to perimenopause -- the insomnia, the tension headaches, the heart palpitations, the eye twitching, the night cramps, the wired-but-tired feeling, the constipation -- could be low magnesium making everything worse.

Omega-3 Index

Optimal: 8-12%. Average perimenopausal woman: 4-5%.

Your brain is 60% fat. The membranes of every neuron are made of fatty acids. Declining estrogen in perimenopause already increases neuroinflammation -- add cell membranes made of inflammatory omega-6 fats instead of anti-inflammatory omega-3s and you have a brain on fire with no protection. The Omega-3 Index measures what your cells are actually made of. Most perimenopausal women's cells are built from seed oils instead of the EPA and DHA their brain needs.

GGT (Gamma-Glutamyl Transferase)

Optimal: under 17 U/L for women. The normal range goes up to 45 -- that is already dysfunction.

Your liver is responsible for clearing estrogen. When it cannot, you become oestrogen dominant -- bloated, puffy, gaining weight while eating carefully, with heavy periods and mood swings. GGT is the earliest, most sensitive marker of liver stress and glutathione depletion. It catches the problem when your liver is just starting to struggle, not when you are already in fatty liver territory. If you feel puffy, inflamed, and toxic, your liver needs support before anything else will work.

OAT (Organic Acids Test)

Ask for: Organic Acids Test (OAT) through a functional medicine practitioner

This is a urine test that gives you a metabolic blueprint of what is happening at the cellular level: mitochondrial function (why your fatigue is bone-deep and sleep does not fix it), neurotransmitter metabolites (why your serotonin crashed, why your dopamine feels off), yeast and bacterial overgrowth (candida and gut dysbiosis that surge in perimenopause because estrogen changes your microbiome), B vitamin status at the cellular level (B6 for progesterone, B12 for energy, folate for methylation), and detox pathway efficiency.

Take this to your GP

Print or screenshot this page and bring it to your next appointment. You are entitled to ask for specific tests. If your GP is not familiar with some of these, a functional medicine practitioner or integrative GP can order them.