Medically reviewed content · Last updated April 2026

Female Hormones: Normal vs Optimal Ranges (and Why Your GP Might Miss the Difference)

You went to your GP because something felt off. Fatigue that sleep does not fix, weight gain around your middle despite eating well, cycles that have changed, mood swings that appeared from nowhere, brain fog that makes you feel like a different person. Your GP ran bloods. The result came back: “Everything is normal.”

But you do not feel normal. And here is the uncomfortable truth that nobody explained: NHS reference ranges are designed to detect disease, not to identify when your hormones are suboptimal. A result can sit inside the “normal” range and still be far from where you would feel your best. The gap between “not clinically ill” and “actually thriving” is enormous — and it is exactly where millions of women in the UK are stuck.

This guide walks through the seven key female hormones, explains what the NHS reference ranges actually mean, shows you where functional and optimal ranges differ, and helps you understand why your results might be technically normal but functionally inadequate. We also cover when to test during your cycle, what patterns suggest conditions like PCOS, perimenopause, or post-pill amenorrhea, and what to do with results your GP has dismissed.

Why “Normal” Does Not Mean Optimal

To understand the problem, you need to understand how NHS reference ranges are created. A laboratory takes a large sample of the population, measures a given hormone, and defines “normal” as the middle 95% of results. That means 2.5% of perfectly healthy people will fall outside the range on either side — and, critically, the reference population includes people who are already symptomatic, overweight, stressed, or on medication.

The result is ranges that are wide. Take testosterone in women: the NHS reference range typically runs from 0.3 to 1.7 nmol/L. A woman at 0.4 nmol/L is technically “normal” but may be experiencing fatigue, low libido, poor muscle recovery, and brain fog that would improve significantly if her testosterone were closer to 1.0–1.2 nmol/L. Her GP has no clinical reason to act because she is not below the lower limit. But she is not thriving either.

Functional medicine and integrative endocrinology take a different approach. Instead of asking “is this result consistent with the absence of disease?” they ask “is this result consistent with this person feeling well?” The distinction matters — and it is where the most meaningful improvements in quality of life happen.

The Seven Key Female Hormones Explained

1. Oestradiol (E2)

Oestradiol is the most potent and biologically active form of oestrogen. It regulates your menstrual cycle, protects bone density, supports cardiovascular health, maintains skin elasticity, and plays a critical role in mood regulation and cognitive function. When women describe “feeling like themselves,” oestradiol is often the hormone that underpins it.

What to watch for: An early follicular oestradiol below 150 pmol/L in a premenopausal woman may indicate declining ovarian reserve, even if technically “within range.” Combined with an FSH above 10 IU/L, this pattern is suggestive of early perimenopause. An oestradiol below 100 pmol/L with ongoing symptoms is a strong case for further investigation regardless of what the reference range says.

2. Progesterone

Progesterone is often called the “calming hormone.” It rises sharply after ovulation, stabilises the uterine lining for potential implantation, promotes restful sleep, reduces anxiety, and counterbalances oestrogen’s proliferative effects. It is also the first hormone to decline as you approach perimenopause — often years before oestradiol drops.

Why this matters: A mid-luteal progesterone of 17 nmol/L technically confirms ovulation. But many practitioners consider levels below 30 nmol/L to be associated with a “weak” luteal phase, which can cause premenstrual anxiety, insomnia, spotting before your period, and difficulty conceiving. A woman with a progesterone of 18 nmol/L may be told she is ovulating normally while experiencing significant symptoms of progesterone insufficiency.

Timing is everything: Progesterone must be tested 7 days after ovulation. For a 28-day cycle, that is day 21. For a 35-day cycle, that is day 28. Testing at the wrong time will give a low result that does not reflect your actual luteal function.

3. Follicle-Stimulating Hormone (FSH)

FSH is produced by your pituitary gland and tells your ovaries to develop follicles. When your ovaries respond well, they produce oestradiol, which feeds back to the pituitary and lowers FSH. As ovarian reserve declines (with age or other factors), the pituitary has to “shout louder” — FSH rises.

The subtlety your GP may miss: An FSH of 10–12 IU/L on day 3 is technically normal. But in a 38-year-old who is also experiencing cycle changes, it may represent the very early stages of declining ovarian reserve. Serial testing over 3–6 months reveals trends that a single snapshot cannot.

4. Luteinising Hormone (LH)

LH works alongside FSH to regulate your cycle. A mid-cycle LH surge triggers ovulation. Outside of that surge, LH should be lower than FSH. The ratio between the two is diagnostically important.

NHS early follicular range: 1.0–12.0 IU/L
Functional optimal: 2.0–6.0 IU/L, with LH ≤ FSH

PCOS pattern: In polycystic ovary syndrome, the LH:FSH ratio is often elevated — typically 2:1 or higher. An LH of 10 with an FSH of 4 gives a ratio of 2.5:1. Both individual values may be “within range,” but the ratio is abnormal and suggestive of PCOS. This is one of the most commonly missed patterns when GPs look at individual numbers rather than ratios.

5. Testosterone

Testosterone is not just a male hormone. Women produce testosterone in the ovaries and adrenal glands, and it plays a critical role in energy, libido, muscle maintenance, bone density, mood, and cognitive function. Testosterone declines gradually from your mid-20s, and by perimenopause, levels may be half of what they were at 25.

Why it gets missed: Many GPs do not test testosterone in women at all. When they do, a result of 0.5 nmol/L is reported as “normal” — technically true, but potentially responsible for significant symptoms. Women in the lower quarter of the reference range frequently report low energy, poor exercise recovery, absent libido, and difficulty building or maintaining muscle.

PCOS caveat: In PCOS, testosterone is often elevated — above 1.7 nmol/L or with a high free androgen index. This causes acne, hirsutism, hair thinning, and irregular cycles. Context matters: high testosterone in a woman with regular cycles and no androgenic symptoms is different from high testosterone with classic PCOS features.

6. DHEA-S (Dehydroepiandrosterone Sulphate)

DHEA-S is an adrenal androgen — a precursor hormone that your body converts into both testosterone and oestrogen. It is the most abundant circulating steroid hormone and declines steadily from your late 20s, a process sometimes called “adrenopause.”

NHS reference range (premenopausal women): 1.0–11.7 µmol/L
Functional optimal: Upper half of age-adjusted range. For women aged 30–40, typically 4.0–8.0 µmol/L.

Why test it: DHEA-S reflects adrenal function and androgen production capacity. A low DHEA-S alongside low testosterone and fatigue may point to adrenal insufficiency or chronic stress depleting your androgen reserves. An elevated DHEA-S alongside high testosterone suggests adrenal-driven androgen excess, which presents differently from ovarian-driven PCOS.

7. SHBG (Sex Hormone-Binding Globulin)

SHBG is a protein produced by your liver that binds to sex hormones — primarily testosterone and oestradiol — making them inactive. The amount of SHBG in your blood determines how much of your total testosterone and oestradiol is actually free and biologically available.

NHS reference range: 20–155 nmol/L
Functional optimal: 40–80 nmol/L

Why it is the most underrated marker on this list: A woman with a total testosterone of 1.0 nmol/L and an SHBG of 120 nmol/L has almost no free testosterone available to her tissues. Her total looks fine; her free is negligible. Conversely, a woman with a testosterone of 1.0 nmol/L and an SHBG of 25 nmol/L has substantially more bioavailable testosterone. Without testing SHBG, you cannot interpret testosterone meaningfully.

What affects SHBG: The combined oral contraceptive pill dramatically raises SHBG — often to 150+ nmol/L — effectively neutralising much of your free testosterone. This is why many women on the pill experience low libido, flat mood, and fatigue. SHBG can remain elevated for 6–12 months after stopping the pill. Insulin resistance, obesity, and hypothyroidism lower SHBG, increasing free androgens and potentially unmasking or worsening PCOS symptoms.

When to Test: Cycle Day Timing

Testing your hormones on the wrong day of your cycle is one of the most common mistakes — and it renders results almost uninterpretable. Hormones are not static; they change dramatically across a 28-day cycle.

If your cycles are irregular: For women with cycles longer than 35 days or unpredictable timing, test the baseline panel (oestradiol, FSH, LH, testosterone, DHEA-S, SHBG) on any day you identify as early in your cycle (light bleeding or the first few days of a new period). For progesterone, you may need to track ovulation with LH strips and test 7 days after the positive.

If you are not menstruating: For women with amenorrhea (no periods), test all hormones at the same time on any convenient day. The lack of a cycle means there is no “wrong” day, and the results themselves will help determine whether the cause is hypothalamic, ovarian, or related to high androgens.

Recognisable Hormone Patterns

Perimenopause Pattern

The hallmark of perimenopause is instability. Oestradiol may swing from very high (sometimes above 1,500 pmol/L) to very low within a single cycle. FSH begins to rise intermittently — above 10 IU/L, then back to normal, then up again. Progesterone declines as anovulatory cycles become more frequent. Testosterone and DHEA-S gradually decrease.

A single blood test during perimenopause can look completely normal. This is why NICE guidelines recommend diagnosing perimenopause clinically in women over 45. For women in their late 30s and early 40s, serial testing every 3–6 months builds a trend that is far more informative than any single result.

PCOS Pattern

Classic PCOS presents with elevated LH relative to FSH (ratio ≥2:1), raised total or free testosterone, low SHBG (often below 30 nmol/L driven by insulin resistance), and oestradiol that may be normal or slightly elevated. Progesterone is typically low because ovulation is infrequent or absent.

Not all PCOS looks the same. “Lean PCOS” may present with normal SHBG and only mildly elevated androgens. Adrenal PCOS shows elevated DHEA-S with normal ovarian testosterone. The full seven-hormone panel is essential for distinguishing subtypes, because treatment differs significantly.

Post-Pill Amenorrhea Pattern

After stopping the combined oral contraceptive pill, some women experience months of absent or irregular periods. The typical hormone pattern shows suppressed LH and FSH (the pituitary is still “waking up”), low oestradiol, absent progesterone (no ovulation), very high SHBG (persistent pill effect), and consequently very low free testosterone despite a potentially normal total.

This pattern usually resolves within 3–6 months, but for some women it persists much longer. Serial testing helps distinguish true post-pill recovery (gradual hormone normalisation) from an underlying condition like hypothalamic amenorrhea or PCOS that was masked by the pill.

Hypothalamic Amenorrhea Pattern

Caused by chronic undereating, overexercising, or severe stress, hypothalamic amenorrhea presents with low FSH, low LH, low oestradiol, absent progesterone, and often low testosterone and DHEA-S. Everything is suppressed because the hypothalamus has downregulated the entire reproductive axis. This pattern requires medical attention as it affects bone density, cardiovascular health, and fertility.

Age-Specific Considerations

Twenties

Hormones should be at or near their peak. Oestradiol, progesterone, and testosterone are typically robust. If you are experiencing symptoms (irregular cycles, acne, hair loss, fatigue), a full panel can identify PCOS, thyroid issues, or nutritional deficiencies early. The pill masks these conditions — consider testing before starting or after stopping hormonal contraception.

Thirties

Subtle declines begin. Testosterone and DHEA-S start their gradual descent. Progesterone quality may start to dip, particularly after 35, as anovulatory cycles become more common. FSH may begin creeping up above 8 IU/L in the late thirties. These changes are normal but can cause symptoms that are easily dismissed as “stress” or “lifestyle.” This is also the decade where fertility concerns often arise, making baseline hormone data invaluable.

Forties

The perimenopause decade. Progesterone declines significantly, oestradiol becomes erratic, FSH rises intermittently, and testosterone continues its decline. Symptoms may include cycle changes, sleep disruption, mood shifts, weight redistribution, and brain fog. Testing every 6 months provides data that supports HRT discussions with your GP or menopause specialist.

Fifty-Plus

Post-menopause brings consistently low oestradiol and progesterone with elevated FSH. If you are on HRT, regular testing helps confirm adequate dosing — many women are under-dosed because they “feel OK” without knowing their levels are still suboptimal. Monitoring testosterone remains important for energy, bone density, and cognitive function.

What to Do When Your GP Says “Normal”

If you have received results labelled as normal but are still experiencing symptoms, here is a practical framework:

1. Request the actual numbers. “Normal” is not a number. Ask for the specific values and reference ranges. In the UK, you have a legal right to your blood test results under GDPR. Many GPs will share them if you ask; some require a formal Subject Access Request.
2. Check the timing. Were you tested on the right cycle day? If your GP tested progesterone on day 10 or oestradiol on day 14, the results may be meaningless for the intended purpose.
3. Look at the full panel. Did your GP test all seven hormones, or just one or two? A single FSH result tells you very little. The pattern across multiple markers tells you far more.
4. Compare to functional ranges, not just reference ranges. Use the tables in this guide to assess where your results sit within the spectrum — not just whether they are inside or outside the NHS boundaries.
5. Consider serial testing. One set of results is a snapshot. Two or three sets over 6–12 months reveal trends. This is particularly important in perimenopause, where single tests frequently look “normal.”
6. Bring data to your GP. GPs respond to objective data. Presenting a trend showing rising FSH, declining progesterone, and low testosterone alongside a symptom diary is far more compelling than saying “I just don’t feel right.”

Complementary Markers Worth Adding

While the seven hormones above form the core female panel, several additional markers provide important context:

• Thyroid function (TSH, free T4, free T3): Thyroid dysfunction mimics many hormone symptoms — fatigue, weight gain, mood changes, hair loss, irregular periods. It is also common in women, especially those with autoimmune conditions.
• Ferritin: Iron deficiency causes fatigue that overlaps almost perfectly with low oestrogen or low progesterone symptoms. Many women are iron-deficient without being anaemic. A ferritin below 30 µg/L is associated with fatigue symptoms even when technically “within range.”
• Vitamin D: Deficiency is endemic in the UK, particularly between October and March. Low vitamin D compounds fatigue, mood disruption, and bone health risks associated with declining oestrogen.
• HbA1c and fasting insulin: Insulin resistance drives PCOS, lowers SHBG, raises free androgens, and promotes weight gain. Testing fasting insulin alongside hormones provides a more complete picture, especially for women with PCOS features.
• Prolactin: Elevated prolactin can suppress ovulation and cause amenorrhea. It is worth testing if periods have stopped or become very irregular without an obvious hormonal explanation.

Frequently Asked Questions

Can I test my hormones while on the contraceptive pill?

Hormonal contraception (the combined pill, mini-pill, implant, or hormonal coil) suppresses your natural hormone production. Testing oestradiol, progesterone, FSH, and LH while on hormonal contraception will show suppressed levels that reflect the medication, not your natural hormone status. SHBG will be very elevated on the combined pill. If you want to understand your natural hormone levels, you need to be off all hormonal contraception for at least 3 months before testing. The copper coil (IUD) does not affect hormone levels and is fine to test with.

How often should I test my hormones?

For a healthy woman in her 20s or early 30s with no symptoms, a baseline panel once a year is reasonable. If you are experiencing symptoms, test every 3–6 months to establish trends. During perimenopause (typically late 30s to early 50s), testing every 6 months provides valuable trend data. If you are on HRT, your prescribing clinician will typically recommend testing 3 months after starting or changing a dose, then every 6–12 months for monitoring.

My GP only tested FSH. Is that enough?

No. FSH alone is a poor screening tool for most female hormone concerns. In perimenopause, a single FSH can be completely normal one month and elevated the next. In PCOS, FSH is often normal while the LH:FSH ratio is abnormal. Without oestradiol, progesterone, testosterone, and SHBG, you cannot build a meaningful picture of your hormonal health. A comprehensive panel of all seven markers plus thyroid function is recommended for any woman investigating hormone-related symptoms.

What does a high SHBG mean for me?

High SHBG binds more of your testosterone and oestradiol, reducing the amount of free (active) hormone available to your tissues. Common causes include the combined oral contraceptive pill, hyperthyroidism, low body weight, and ageing. Symptoms of high SHBG overlap with low testosterone: fatigue, low libido, poor muscle recovery, dry skin. If your total testosterone looks normal but your SHBG is high, your effective free testosterone may be very low.

Can I get these tests on the NHS?

GPs can request most of these tests, but in practice, NHS hormone panels are often limited to FSH and sometimes oestradiol. Testosterone, DHEA-S, and SHBG are rarely tested in women unless there is a strong clinical indication (such as suspected PCOS or hirsutism). Progesterone is typically only tested to confirm ovulation in fertility investigations. Private blood testing allows you to request the full panel, test at the correct time in your cycle, and receive results within days rather than weeks.

What is the Free Androgen Index and should I ask for it?

The Free Androgen Index (FAI) is a calculation: (total testosterone ÷ SHBG) × 100. It estimates free testosterone without needing a direct free testosterone assay, which is technically difficult and less reliable. An FAI above 5 in women suggests androgen excess and is commonly used in PCOS diagnosis. If you have both total testosterone and SHBG results, you can calculate the FAI yourself. It is a far more useful number than total testosterone alone.