Low Testosterone in Men: Symptoms, Normal Levels and the Blood Test

The NHS lists depression, loss of sex drive, erectile dysfunction, mood swings, loss of muscle, fat redistribution, low energy, poor sleep and poor concentration, and says "in many cases the symptoms are nothing to do with hormones". A GP may order a blood test, taken fasting in the morning and repeated if low or borderline; a specialist confirms any deficiency.^{1, 2} More in the Wellgard men's health guide.

Evidence at a glance

• Rests on: the NHS "male menopause" page, NICE's primary-care summary, the 2023 British Society for Sexual Medicine (BSSM) guideline and the European Male Ageing Study (EMAS: 3,369 men aged 40 to 79).^{1, 2, 3, 4}
• Largest single study: 9,054 men in four pooled cohorts; the middle 95% of healthy non-obese men aged 19 to 39 ran from 264 to 916 ng/dL.⁵
• Strongest measured outcome: only poor morning erections, low sexual desire and erectile dysfunction clustered with low testosterone; 2.1% met the full definition.^{3, 4}
• Not set: a NICE guideline on testosterone deficiency, or a single UK reference range.^{3, 6}

Sources checked on 13 October 2026.

What is testosterone, and what does the NHS mean by the "male menopause"?

Testosterone is the principal male hormone, made in the testes and "essential for the development and maintenance of secondary male characteristics", says BSSM.³ Blood tests report total testosterone; free testosterone can be calculated from it, sex hormone binding globulin and albumin.²

The NHS page, last reviewed 13 October 2022 and now overdue for review, calls the "male menopause" "an unhelpful term" and says the decline is "steady at about 1% a year from around the age of 30 to 40, and this is unlikely to cause any problems in itself". Late-onset hypogonadism is "an uncommon and specific medical condition that's not a normal part of ageing".¹

What are the symptoms of low testosterone?

The NHS lists these for men in their late 40s to early 50s:¹

• depression
• loss of sex drive
• erectile dysfunction
• mood swings and irritability
• loss of muscle mass and reduced ability to exercise
• fat redistribution, such as developing a large belly or "man boobs" (gynaecomastia)
• a general lack of enthusiasm or energy
• difficulty sleeping (insomnia) or increased tiredness
• poor concentration and short-term memory

It says "in many cases the symptoms are nothing to do with hormones", naming stress, depression, anxiety, lack of sleep, a poor diet, lack of exercise, drinking too much alcohol, smoking and low self-esteem.¹ In EMAS, only the three sexual symptoms clustered with low testosterone; BSSM calls fatigue and sleep disturbance less specific.^{3, 4} Other NHS pages add relationship problems, some medicines, sleep apnoea, anaemia, diabetes and thyroid problems.^{7, 8}

What causes low testosterone?

The NHS says hypogonadism is sometimes present from birth, with delayed puberty and small testes, and occasionally develops later, "particularly in men who are obese or have type 2 diabetes".¹ In Klinefelter syndrome the testicles may produce less testosterone than usual.⁹ In 3,200 European men aged 40 to 79, a body mass index of 30 or more went with total testosterone about 5 nmol/L lower than under 25.¹⁰ BSSM reports hypogonadism in 25% to 80% of men on long-term prescribed opioid painkillers: a GP question; never stop a prescribed medicine on your own.³ The NHS lists shrunken testicles, a reduced sperm count and infertility among the effects of anabolic steroids in men, and says a GP can help anyone who wants to stop.¹¹ Pooled studies of 1,823 men linked sleep apnoea with lower testosterone, with a significant difference in severe but not mild apnoea; the NHS says gasping or choking noises in sleep need a GP.^{8, 12} Weight and alcohol: how to increase testosterone naturally; sleep: the Wellgard sleep guide.

How is testosterone tested in the UK?

With a blood test a GP may order.¹ NICE's primary-care summary on erectile dysfunction asks for "a fasting serum total testosterone (taken between 9–11 am)" and, if low or borderline, a repeat with LH, FSH, sex hormone binding globulin and prolactin.² BSSM asks for samples between 7 and 11 am "on at least 2 occasions", preferably four weeks apart, not during an acute illness; non-fasting levels may be up to 30% lower.³

In 66 Boston men, testosterone at ages 30 to 40 was 20% to 25% lower at 4 pm than at 8 am, and 17 men with a low afternoon result were normal at every morning visit.¹³ In a London analysis of 266 people, testosterone fell 34.3% after a mixed meal.¹⁴ If you have a test done privately, take the result to your GP: UK guidance reads a single result only with your symptoms and a second morning sample.

What is a normal testosterone level for a man, by age?

There is no single UK number; BSSM notes "wide variations in laboratory practice".³

This page explains what the NHS and UK guidance say; it cannot tell you whether your own result is low. A GP reads a result alongside your symptoms and a repeat morning test.

The EMAS definition was met by 0.1% of men in their 40s and 5.1% in their 70s; 75% of men kept normal testosterone into old age.³

When should you see a GP, and what happens next?

The NHS says to see your GP, who will ask about work and personal life in case stress or anxiety is behind the symptoms; medication or a talking therapy may help, as can exercise and relaxation. If a blood test suggests a deficiency, the GP may refer you to an endocrinologist, "a specialist in hormone problems", as NICE's summary also advises.^{1, 2}

Testosterone replacement is a prescription treatment that a specialist decides on after confirming a deficiency; the NHS says it may be given as an injection or a gel.¹ Erection problems that keep happening can be a sign of a health condition, so the NHS advises seeing a GP or a sexual health clinic.¹⁶ Under-18s with questions about puberty or growth should see a GP.

Can lifestyle changes raise a low testosterone level?

In some studies. Testosterone rose in weight-loss studies BSSM reviewed, though in EMAS free testosterone rose significantly only after large weight loss, and BSSM does not back lifestyle change alone as the first step for a confirmed deficiency.³ The studies are in how to increase testosterone naturally.

What have supplement trials found?

A 2024 review of 52 studies of 27 ingredients found most did not raise total testosterone against placebo; tongkat ali, ashwagandha and a purified shilajit extract were rated possibly effective in particular groups of men.¹⁷ Zinc contributes to the maintenance of normal testosterone levels in the blood, and its trials were in men low in zinc.¹⁸ Ingredient by ingredient: testosterone supplements.

What we don't know

• NICE has no guideline on testosterone deficiency: a search of its site on 13 October 2026 returned only the fertility guideline.⁶
• In EMAS's 4.3-year follow-up, recovery of low levels was not linked with better symptoms, as BSSM reports it.³
• The prevalence figures cover European men aged 40 to 79 only.³

Frequently asked questions

Can low testosterone cause erection problems?

It can be one cause. The NHS lists hormone problems among the causes of frequent erectile dysfunction; in EMAS it was one of three symptoms that clustered with low testosterone; NICE's summary checks morning testosterone in men with erection problems.^{2, 4, 16}

Can low testosterone make you angry or emotional?

The NHS lists depression, mood swings and irritability among the symptoms, and says mood swings may be the result of stress, depression or anxiety.¹

What are the signs of high testosterone in men?

A natural result above the laboratory's range is a GP question. The NHS says anabolic steroids "copy the effects of male hormones, such as testosterone", and lists severe acne, breast development, aggressive behaviour and mood swings among their effects.¹¹

Is a testosterone level of 9.5 or 300 low?

Both 9.5 nmol/L and 300 ng/dL (10.4 nmol/L) sit in the 8 to 12 nmol/L band where UK specialist guidance checks free testosterone and repeats the morning test; symptoms and the repeat decide.^{3, 13}

Sources

1. NHS. The "male menopause". Page last reviewed 13 October 2022 (review overdue). nhs.uk.
2. NICE Clinical Knowledge Summary. Erectile dysfunction: assessment and management. Last revised July 2026.
3. Hackett et al., 2023. BSSM guideline, 25 statements; society-funded; the lead author declares advisory roles, and a co-author travel grants, with testosterone-therapy companies. PubMed 36876744.
4. Wu et al., 2010. EMAS: observational, 3,369 men aged 40 to 79. PubMed 20554979.
5. Travison et al., 2017. Pooled cohorts, 9,054 men, four US and European studies. PubMed 28324103.
6. NICE. Search for "testosterone deficiency", 13 October 2026: one result, NG257. nice.org.uk.
7. NHS. Low sex drive (loss of libido). Page last reviewed 26 May 2026. nhs.uk.
8. NHS. Tiredness and fatigue. Page last reviewed 2 June 2023 (review overdue). nhs.uk.
9. NHS. Klinefelter syndrome. Page last reviewed 20 February 2023 (review overdue). nhs.uk.
10. Wu et al., 2008. EMAS: observational, 3,200 men aged 40 to 79. PubMed 18270261.
11. NHS. Anabolic steroid misuse. Page last reviewed 16 January 2026. nhs.uk.
12. Su et al., 2022. Pooled analysis of 18 observational studies, 1,823 men. PubMed 34536053.
13. Brambilla et al., 2009. Observational, 66 men; publicly funded (PubMed grant record). PubMed 19088162.
14. Abbara et al., 2024. Observational analysis, 266 people; publicly funded. PubMed 37977226.
15. Harman et al., 2001. Observational, 890 men followed over years. PubMed 11158037.
16. NHS. Erectile dysfunction (impotence). Page last reviewed 28 July 2023 (review overdue). nhs.uk.
17. Morgado et al., 2024. Systematic review, 52 studies of 27 ingredients. PubMed 37697053.
18. Prasad et al., 1996. Cross-sectional, 40 men, plus uncontrolled studies of 4 and 9 men; government-funded (PubMed record). PubMed 8875519.

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