Low testosterone
Low testosterone means your body makes less testosterone than it needs, and that you have complaints from it. You notice it mostly as less desire for sex, sometimes with tiredness or irritability. One value in your blood shows where you stand: testosterone, measured in the morning. Testosterone falls with the years, and that fall on its own is not a deficiency. It is also called hypogonadism.
What are the symptoms of low testosterone?
How strong is the evidence?
- strong
- In the Dutch guideline, or confirmed in several controlled trials.
- fair
- From one controlled trial, an international guideline or a review of research.
- limited
- The research does not point one way.
Evidence as of October 2026. New research can shift this.
These complaints are also described with iron deficiency, anaemia, an underactive thyroid, a vitamin B12 deficiency, a vitamin D deficiency.
A falling testosterone you do not feel as a number. From 35 years it falls gradually in healthy men, and that fall is ordinary; in older men without clear indications measuring therefore makes little sense. The complaints above are each of them very common without a deficiency too, and that is precisely why the diagnosis asks for complaints and a twice-measured low testosterone.
None of these complaints belongs to low testosterone alone, and a measurement explains no complaint: the reading and the diagnosis belong with your GP. The complaint list follows the Dutch GP guideline on sexual complaints (NHG).
When is your testosterone too low?
Normal for men:
9.0 to 27.3 nmol/L
Enter your value as it appears on your results. Range for adults.
No value yet? How to get it measured
How do you raise your testosterone?
See what is pushing your testosterone down
Lose weight
Having your medicines checked
Measuring twice, in the morning
Testosterone replacement
Follows the Dutch GP guideline on sexual complaints (NHG) and the European urology guideline.
What causes low testosterone?
Weight and health
Weight and health
- Excess weight, belly fat above all: in one cohort waist circumference had more influence than age
- Diabetes, in which testosterone is on average 2.66 nmol/L lower
- Chronic illnesses such as HIV, COPD or cancer, and poor general health
Medication
Medication
- Opiates
- Corticosteroids such as prednisone
- Anti-epileptics
Pituitary or testes
Less common
Pituitary or testes
Less common- A pituitary tumour such as a prolactinoma, or a pituitary that makes too little
- Klinefelter syndrome or another chromosomal condition
How to get low testosterone measured
Every value below has its own page: what is normal, and what your value means.
| Value | What it shows | Points here when |
|---|---|---|
| Total testosteronedefining | The number the NHG steers on: an average below 11 nmol/L, measured twice before ten in the morning. | low |
And 7 values that complete the picture
| Value | What it shows | Points here when |
|---|---|---|
| SHBG | Binds 60% of testosterone. Rises with age and falls with excess weight, and so decides how much of the total works. | abnormal |
| Free testosterone | The working share, calculated from total, SHBG and albumin. Reads a normal total with a high SHBG as low after all. | low |
| FAI (free androgen index) | Total divided by SHBG: the same question in one ratio. | low |
| LH | The pituitary's order. High with a low testosterone points to the testes, low to the pituitary itself. | abnormal |
| FSH | The second pituitary hormone, pointing in the same direction. | abnormal |
| Prolactin | A high prolactin can suppress testosterone production; a prolactinoma is one of the central causes the NHG wants excluded. | high |
| Oestradiol | Made from testosterone, mostly in fat tissue. Says something about the balance, not about the deficiency itself. | abnormal |
- Every draw is fasted: nothing to eat or drink from midnight, only water. Appointments are therefore in the morning, until 12:00.Plan as early as you can: testosterone is measured before ten in the morning, because the value comes out lower later in the day.
- You can draw at 600+ locations near you, no referral needed. See the locations
- Results within 24 hours of analysis, in the app.
What is low testosterone?
Testosterone is the hormone that steers muscles, bone, brain, skin, prostate and sexual organs. It is made in the testicles, on the orders of the pituitary through LH and FSH. Of the testosterone in your blood only 2% is free; about 60% is firmly bound to SHBG and 38% loosely to albumin. Only the free and the albumin-bound part works, and that is why SHBG has a say in how much of a total value remains. From 35 years testosterone falls slowly in healthy men; a man of 75 still has about 70% of the value of a 25-year-old. That fall is ordinary, and the link with complaints is unclear in healthy older men. What lowers it harder than the years is the belly: in a cohort waist circumference had more influence on testosterone than age, and men with diabetes have on average 2.66 nmol/L less. Lack of sleep, heavy stress, alcohol and medicines such as opiates and prednisone lower it too, and it recovers once the cause is gone. The value has a daily rhythm, with its peak in the morning, and fluctuates from day to day. That is why testosterone is drawn before ten in the morning, and with a value below 11 nmol/L once more after a few weeks; the average of the two counts. A true deficiency, in which the testicles or the pituitary make too little, is rare and can be recognised from LH and FSH.
What is low testosterone confused with?
Each with the one value that tells the two apart.
Erection problems without a deficiency
By far most erection problems have a vascular or psychological cause. The NHG only has testosterone measured when less desire is in the foreground and there are other indications; otherwise a normal testosterone says nothing new.
Prolactinoma
A benign pituitary growth that makes prolactin and so suppresses testosterone. Prolactin points that way, and it is the central cause the urologist rules out.
Also tired, low and less desire, through a different hormone. TSH keeps the two apart.
Type 2 diabetes
Erection problems are a late sign of diabetes, and men with diabetes have a lower testosterone on average. Whether that is cause or effect is not known; fasting glucose says whether sugar is part of it.
Frequently asked questions
By complaints and a blood value together: less desire for sex and less arousal, erectile problems, marked tiredness, irritability, a poorer memory, mood changes and muscle weakness, and on examination small testicles, little body hair, little muscle mass and more belly fat. Each of those complaints is also common without a deficiency, with lack of sleep, stress and excess weight first of all, and that is why the diagnosis asks for complaints and a twice-measured low testosterone.
Sources 3
- 1.NHG-Standaard Seksuele klachten. 2023. richtlijnen.nhg.org
- 2.Bhasin S et al., Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline, Journal of Clinical Endocrinology & Metabolism. 2018. doi.org
- 3.European Association of Urology, Guidelines on sexual and reproductive health. 2025. uroweb.org
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This page explains what a result means. It is not a diagnosis and not treatment advice. Discuss complaints or an abnormal value with your doctor.
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