What are the symptoms of low testosterone?

The symptoms usually described include reduced sex drive, erectile difficulties, low energy, low mood, reduced muscle mass and disturbed sleep. Reading that list is where most people start, and it is also where the difficulty begins.

Every item on it is caused far more often by something else. Poor sleep, depression, thyroid problems, medication effects and simply being unwell all produce the same picture. The NHS is explicit that these symptoms are common in men who do not have low testosterone at all, and that they warrant looking for other causes.

This is why the route is a blood test interpreted by a clinician rather than a symptom checklist. Testosterone follows a daily rhythm and results vary between laboratories, so a single number read against a range you found online tells you very little. If the list above sounds like you, that is a reason to book an appointment, not to reach a conclusion.