Low Libido in Men: Testosterone, Mood and What Actually Helps

Losing interest in sex is one of the harder things to say out loud. Most men I see about it have waited months, sometimes years. Many arrive with a theory already in place: their testosterone must be low.

Sometimes that theory is right. Often it is only part of the story. And sometimes it points in exactly the wrong direction.

Here is the pattern I see in clinic. One man has a borderline testosterone result and a partner he no longer feels close to. Another has a perfectly normal result, a new antidepressant and a job that leaves him exhausted. Both say the same words: "I just don't want it any more." Both expect a hormone answer.

Desire is not a single switch. Specialists describe three parts to it. There is drive, which is biological. There is motivation, which is psychological. And there is wish, which is shaped by culture, upbringing and your relationship. In real life the three are tangled together.

Testosterone matters for desire. But the European Association of Urology makes a point that surprises many people. How much desire you feel does not track neatly with your testosterone level, especially as men get older. A number on a lab report is part of the picture, not the whole of it.

That is why I don't treat low libido as a blood test with a patient attached. I treat it as a question about your body, mood, medicines and relationship. The blood test is one of the tools we use to answer it.

This page walks you through what low libido is, what usually causes it, how testosterone fits in, what a proper assessment looks like, and what can actually help. It is part of my wider guide to sexual health and wellbeing.

Low desire or a low mood about sex — what counts as a problem?

There is no "normal" amount of sexual desire. It varies between people, and it changes across a lifetime. A drop in interest is only a medical problem if it bothers you, or it is causing strain in your relationship.

Doctors use the term low sexual desire for this. When it is persistent and distressing, the formal name is male hypoactive sexual desire disorder. That means a lasting lack, or absence, of sexual thoughts, fantasies and wish for sex. The judgement always takes your age and your life into account.

One distinction matters a great deal. Is loss of desire the main problem? Or is it a knock-on effect of something else, such as trouble getting an erection or coming too quickly? In my experience, men who struggle with erections often start avoiding sex, and that avoidance can feel exactly like low desire.

How common is it? We don't know exactly. One large German study of more than 12,000 middle-aged men found it in about 1 in 20.

What usually lowers desire — and why it is rarely just one thing

The list of possible causes is long. In practice, most men have more than one at the same time. The European guideline groups them broadly like this.

• • Mood and mind:
• • depression, anxiety, anger and post-traumatic stress.
• • Relationship factors:
• • conflict, distance, or worry about where the relationship is going.
• • Hormones:
• • low testosterone, a raised level of prolactin (a hormone made by the pituitary gland in the brain) and, less certainly, thyroid problems.
• • Medicines:
• • antidepressants in particular.
• • Other sexual problems:
• • erectile dysfunction, premature ejaculation and urinary symptoms.
• • General health:
• • heart disease, stroke, kidney failure, epilepsy, HIV, and chronic prostatitis or pelvic pain.
• • Body and lifestyle:
• • ageing, heavy bodybuilding, eating disorders, smoking and poor overall health.

Anxiety deserves a special mention. When you are anxious, your attention drifts from what is arousing to what could go wrong. Worrying about your erection during sex is one of the clearest predictors of low desire in men. It can become a loop: worry dampens desire, and low desire feeds the worry.

Where testosterone fits in — and where it doesn't

Testosterone is the main male sex hormone. It is made mostly in the testicles. When levels are genuinely low and you have symptoms, doctors call this testosterone deficiency, or hypogonadism. When it appears later in life, it is called late-onset hypogonadism.

Specialists list reduced libido, erection problems and fewer morning erections among the symptoms most closely linked to low testosterone. Tiredness, low mood and lack of motivation can also appear. But many things other than hormones cause those too.

That is the key point. Low desire on its own does not prove low testosterone. A normal result does not mean your low desire is "all in your head" either. It means we need to look elsewhere for the main cause.

Some men have what doctors call functional hypogonadism. Their testosterone is low because of something else — excess weight, diabetes, another illness or a medicine. In that situation, the guideline advises treating those causes first. Weight loss and lifestyle change come before testosterone.

What a proper assessment looks like

When you come to see me about low desire, most of the first appointment is conversation. That is deliberate. The guideline puts your medical and sexual history at the centre of the diagnosis.

I will ask about:

• • when the change started, and whether it was sudden or gradual
• • whether you still have sexual thoughts, fantasies or desire to masturbate
• • erections, including morning erections, and ejaculation
• • your mood, sleep, stress and alcohol use
• • every medicine and supplement you take, including anything bought online
• • your relationship, if you have one, and how your partner sees the problem
• • whether you may want children in future

I will also examine you. This can pick up physical signs linked to low hormones, or a problem with the penis or testicles that is affecting sex.

Then come blood tests to rule out hormone problems. That usually means testosterone, prolactin and thyroid function, taken in the right way and at the right time of day. I sometimes ask men to fill in a short questionnaire about desire, which helps us track change over time.

If erections are part of the picture, my guide to erectile dysfunction tests explains what else may be worth doing.

What actually helps

Treatment depends on the cause. That sounds obvious, but it is the step most often skipped. Here are the main routes, and most men need more than one.

Depression deserves its own mention. If low mood is behind the loss of desire, treating the depression matters most. For these men, talking therapy can make medication work better.

If you would like help with the psychological side, my page on psychosexual counselling explains what it involves. For many men, this is where the real change happens.

Is testosterone therapy right for you?

Testosterone replacement therapy, often shortened to TRT, can improve sexual desire and sexual thoughts. But only in the right men. The European guideline recommends it when low desire comes with the signs and symptoms of genuine testosterone deficiency, confirmed by proper testing.

It is just as clear about when not to use it:

• • not in men whose testosterone is normal
• • not as a fertility treatment, and not in men who want to become fathers
• • not to lose weight, or to boost energy, strength or thinking in older men

The fertility point is the one I most need you to hear. Testosterone taken as a medicine tells your brain to stop signalling the testicles, and sperm production falls. If children are still a possibility for you, tell me before any treatment is discussed. My article on TRT and fertility explains why, and a semen analysis can be a sensible first step.

TRT also needs regular blood tests once you start, including your red blood cell count. Testosterone can raise it, and a high count is linked to a greater risk of blood clots and heart problems. Men with a history of prostate cancer need very careful individual advice. The full picture of benefits, risks and monitoring is on my testosterone replacement therapy page.

It isn't only your problem — the relationship side

Low desire is the most common complaint that brings couples to therapy. That is worth knowing, because it means you are far from alone.

Specialists increasingly think about "desire discrepancy" rather than one person's "low libido". Two people rarely want sex at exactly the same level, and the gap shifts over time. Seeing it this way removes blame. It also opens up practical ways to meet in the middle.

If you have a partner, it often helps if they come to an appointment. That is your choice, and many men prefer to start alone.

What you can do this week

You don't need to wait for an appointment to start. These steps are useful whatever the cause turns out to be.

1. 1. Write down when the change started, and anything else that changed around then.
2. 1. List every medicine and supplement you take, including anything bought online.
3. 1. Notice whether you still have morning erections. It is useful information for your doctor.
4. 1. Look honestly at sleep, alcohol, weight and stress. Each one affects desire.
5. 1. Don't start testosterone bought online. Unmonitored hormones can harm your fertility and your health.
6. 1. Book an appointment with your GP or a specialist, and bring your notes.

Your GP is a good place to start. If you would like a specialist opinion, I am happy to see you.

Questions men often ask about low libido

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