Low Testosterone: What Is Real, What Is Hype, What Helps
Few areas of men health attract as much marketing as testosterone. Advertisements describe tiredness, a thickening waist and a fading sex drive as signs of low testosterone, and offer a clinic, a gel or a supplement as the answer. Some of those men genuinely have low testosterone. Many do not, and a good number of those who do have a cause that can be fixed without hormones at all.
This article separates the real condition from the marketed one, explains how it should actually be tested, and sets out a consequence of treatment that is rarely mentioned in the advertisements: replacing testosterone can switch off fertility.
📉 Some decline with age is normal. Testosterone levels tend to fall gradually from middle age, by roughly one per cent a year, and the rate varies widely between men. Many older men have levels well within the normal range, and a gradual fall is not in itself a disease.
What doctors call low testosterone, or hypogonadism, requires both consistently low blood levels and symptoms that fit. Either one alone is not enough to justify treatment.
🔎 The symptoms, and which ones matter most
| Symptom | How strongly it points to low testosterone |
|---|---|
| Reduced sex drive | The most specific symptom |
| Fewer spontaneous or morning erections | Fairly specific |
| Erectile difficulty | Common, but more often caused by blood vessel problems than by testosterone |
| Breast tissue enlargement or tenderness | Suggestive, and worth investigating |
| Hot flushes and sweats | Suggest a marked fall |
| Loss of body hair, reduced shaving | Suggests long-standing low levels |
| Reduced muscle, increased body fat | Non-specific |
| Fatigue, low mood, poor concentration | Very non-specific — far more often due to something else |
| Low bone density or fracture after minor injury | Worth checking testosterone as part of the assessment |
The pattern to notice is that the symptoms advertisements lead with — tiredness, low energy, low mood — are the least specific. They are just as consistent with poor sleep, depression, an underactive thyroid, anaemia or sleep apnoea, and assuming testosterone is responsible often means the real cause is missed.
🧪 Testing it properly
This is where many diagnoses go wrong. Testosterone levels vary through the day and are affected by food and illness, so a casual blood test can suggest a problem that does not exist.
| Requirement | Why |
|---|---|
| Blood taken in the morning, roughly between 7 and 11am | Levels are highest in the morning and fall later in the day |
| Ideally fasting | Eating, particularly sugar, can lower the result |
| Repeated on a second day | A single low result is not enough to diagnose |
| Not during or just after an illness | Acute illness temporarily suppresses levels |
| Further hormones checked if low | Pituitary signalling hormones distinguish a testicular problem from a brain signalling problem |
| Prolactin and binding protein where relevant | Raised prolactin can lower testosterone; binding protein changes the free amount |
If testosterone is confirmed low, the pituitary hormones matter. A low testosterone with high signalling hormones points to a problem in the testes. A low testosterone with low or normal signalling hormones points to a problem higher up — including, occasionally, a pituitary tumour raising prolactin, described in the article on pituitary adenoma.
⚖️ The causes that can be fixed first
A large share of low testosterone in adult men is secondary to something else — and treating that something else often raises testosterone without any hormone therapy.
| Cause | What helps |
|---|---|
| Excess weight | The most common cause. Fat tissue converts testosterone to oestrogen and suppresses production. Weight loss can raise levels substantially |
| Type 2 diabetes | Strongly associated. Better control and weight loss help |
| Sleep apnoea | Disrupted sleep lowers testosterone. Treating it can improve levels |
| Opioid painkillers | Suppress the hormonal signal. Reducing them can restore levels |
| Steroid tablets | Long-term use suppresses production |
| Heavy alcohol use | Directly damages production |
| Previous anabolic steroid use | Can shut down natural production for months or years after stopping |
| Very intense training with low food intake | Low energy availability suppresses hormones |
| Raised prolactin | From medication or a pituitary cause; treatable |
Weight is by far the largest lever. Modest weight loss often produces a meaningful rise in testosterone, and the improvement in energy and sexual function that follows is frequently attributed to hormones when it is really the weight loss itself.
💊 Testosterone replacement: benefits and trade-offs
In men with genuinely low testosterone and fitting symptoms, replacement can improve sex drive and sexual function, bone density, muscle mass and, to a modest degree, mood and energy. It also corrects the mild anaemia that low testosterone can cause.
But it is a long-term treatment with real monitoring requirements, and it is not appropriate for men whose only issue is a gradual age-related decline within the normal range.
🔴 Testosterone replacement switches off sperm production. Taking testosterone from outside tells the brain to stop signalling the testes, and sperm production falls, often to zero. Men who want to have children, now or later, should not take testosterone replacement without first discussing fertility-preserving alternatives. Recovery after stopping is possible but can take many months and is not guaranteed.
| Risk or requirement | What it means |
|---|---|
| Thickening of the blood | Red cell count rises and must be checked regularly. Too high increases the risk of clots |
| Prostate monitoring | Prostate checks before and during treatment. Not used in men with prostate cancer |
| Sleep apnoea | Can be worsened, particularly if untreated |
| Heart rhythm | A large trial found no increase in heart attacks or strokes overall, but a higher rate of irregular heart rhythm and some other events |
| Acne, breast tissue, fluid retention | Possible, and usually manageable |
👶 Raising testosterone while protecting fertility
For men whose low testosterone comes from reduced brain signalling rather than a testicular problem, there is another approach. Instead of replacing testosterone from outside, some medicines stimulate the body to make more of its own.
Clomiphene, better known as a fertility medicine for women, is used off-label in men for this purpose. It increases the brain signal to the testes, which raises natural testosterone while maintaining sperm production. It is not suitable for every cause of low testosterone and needs supervision and blood monitoring, but for younger men who want children it is often a better first option than replacement.
Other options sometimes used in specialist care include hormone injections that mimic the natural signal, and medicines that reduce the conversion of testosterone to oestrogen in men with excess weight.
🚫 Supplements and boosters
Products sold as testosterone boosters generally have little or no evidence that they raise testosterone meaningfully. Worse, analyses of some bodybuilding and performance supplements have found undeclared anabolic steroids — which can shut down natural production and carry the same fertility and blood risks as prescribed hormones, without the monitoring. The wider problem with supplements is described in the article on supplements and the health halo.
Zinc and vitamin D only help where there is a genuine deficiency. Neither raises testosterone in men with normal levels.
❤️ Erections and testosterone
Erectile difficulty is the most common reason men ask about testosterone, but low testosterone is often not the main cause. Erections depend first on healthy blood vessels, which is why erectile problems can be an early warning sign of heart disease, as the article on erectile dysfunction explains.
In practice, tablets for erectile dysfunction work in most men regardless of testosterone level. Where testosterone is genuinely low and those tablets have not worked well, correcting testosterone can improve the response. For most men, though, the tablets and attention to blood vessel health do more than hormones.
🩺 When to seek help
- Reduced sex drive, fewer morning erections or erectile difficulty that persists
- Breast tissue enlargement or tenderness
- Hot flushes, loss of body hair or reduced shaving
- A fracture after minor injury
- Headaches or visual changes alongside low testosterone symptoms — pituitary causes need checking
- Difficulty conceiving
- Before starting any testosterone product, including anything bought online
- On testosterone treatment: calf pain or swelling, chest pain, breathlessness or palpitations need urgent assessment
This pharmacy does not supply testosterone. Treatment for erectile dysfunction is stocked in the mens health category, including Cialis Super Active (tadalafil) and Caverta (sildenafil). Clomiphene, used off-label in men to raise natural testosterone while preserving fertility, is available as Fertomid and must be used under medical supervision with blood monitoring.
❓ Frequently asked questions
What are the main signs of low testosterone?
The most specific is reduced sex drive, followed by fewer spontaneous or morning erections. Breast tissue enlargement, hot flushes and loss of body hair also point that way. Tiredness, low mood and poor concentration are common but very non-specific, and are more often caused by poor sleep, depression, thyroid problems or sleep apnoea.
When should testosterone be tested?
In the morning, roughly between 7 and 11am, ideally fasting, and not during or just after an illness. Levels are highest in the morning and are lowered by food and illness. A low result should be repeated on a second day before calling it low.
Is falling testosterone with age a disease?
Not in itself. Levels tend to fall gradually from middle age, but many older men remain in the normal range. Treatment is considered only when levels are consistently low and there are fitting symptoms, not for age alone.
Can losing weight raise testosterone?
Yes, and often substantially. Excess weight is the commonest cause of low testosterone in adult men, because fat tissue converts testosterone to oestrogen and suppresses production. Treating sleep apnoea, improving diabetes control and reducing alcohol can also raise levels without hormones.
Does testosterone replacement affect fertility?
Yes. External testosterone signals the brain to stop stimulating the testes, and sperm production falls, often to zero. Men who want children should not take it without first discussing alternatives such as clomiphene. Recovery after stopping can take many months and is not guaranteed.
How can testosterone be raised without losing fertility?
In men whose low testosterone comes from reduced brain signalling, clomiphene can be used off-label to increase the signal to the testes, raising natural testosterone while maintaining sperm production. It is not suitable for every cause and needs supervision and blood monitoring.
What are the risks of testosterone treatment?
The most important is thickening of the blood, which needs regular monitoring. Others include suppressed fertility, possible worsening of sleep apnoea, acne and breast tissue changes. A large trial found no overall increase in heart attacks or strokes, but a higher rate of irregular heart rhythm. Prostate checks are needed before and during treatment.
Do testosterone boosters work?
Most have little or no evidence of raising testosterone meaningfully. Some performance supplements have been found to contain undeclared anabolic steroids, which can shut down natural production and carry hormone risks without monitoring. Zinc and vitamin D only help where there is a real deficiency.
Will fixing testosterone cure erectile dysfunction?
Usually not on its own. Erections depend first on healthy blood vessels, and erectile dysfunction tablets work in most men regardless of testosterone. Where testosterone is genuinely low and tablets have not worked well, correcting it can improve the response.
Can past steroid use cause low testosterone?
Yes. Anabolic steroids shut down the body own production, and after stopping it can take months or even years to recover, sometimes incompletely. This is a common and under-recognised cause of low testosterone in younger men, and it deserves an honest conversation with a doctor.
📑 Sources and editorial
- Clinical guidelines on the diagnosis and treatment of male hypogonadism
- Evidence on diurnal variation, food effects and repeat testing of serum testosterone
- Literature on obesity, type 2 diabetes, sleep apnoea and opioids as causes of low testosterone
- Evidence on weight loss and testosterone recovery
- Large randomised trial on cardiovascular safety of testosterone replacement in middle-aged and older men
- Literature on suppression of spermatogenesis by exogenous testosterone and recovery after stopping
- Evidence on off-label clomiphene for secondary hypogonadism and fertility preservation
- Regulatory analyses of undeclared anabolic steroids in dietary supplements
- Evidence on testosterone and response to phosphodiesterase type 5 inhibitors
- Related reading: erectile dysfunction, pituitary adenoma, steroids and hormones
- Related products: mens health category
- RXshop Editorial Team — reviewed by Daniel Kim, MD, Endocrinology
Medical Disclaimer: The information in this article is for educational and informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek guidance from a qualified healthcare provider with any questions you may have regarding a medical condition, and before starting, stopping or changing any medication.