What Are The Signs of Low Testosterone?

What are the signs of low testosterone?

Common misconceptions about low testosterone is that it only causes muscle loss or low libido, or that it only affects men. In reality, it’s much more complex than that.

This guide will go through the full range of physical and mental symptoms that can be linked to low testosterone in both men and women, as well as how they can impact your day-to-day life.

Medically reviewed by

Daniel Atkinson, Clinical Reviewer

Extreme tiredness

Although fatigue can have many causes that have nothing to do with low testosterone, feeling tired despite getting a normal seven or eight hours of sleep is a common symptom of low T. And if you’re wondering whether it’s just everyday tiredness or something more, one clue is that testosterone-related fatigue is often accompanied by other symptoms, like lack of motivation, loss of muscle mass, difficulty concentrating, low mood, and even depression.

This is because when your testosterone drops below normal levels, it can change how your cells produce and use energy and leave you feeling constantly drained.

Weight gain

If you feel like you’ve been gaining belly fat or developing enlarged breast tissue, even if you exercise regularly, this could be another sign that your testosterone levels are low. Clinical trials have found that testosterone replacement therapy (TRT) potentially can reduce body fat, especially around the middle of your body (the trunk).

In both men and women around or after menopause, low testosterone levels can contribute to a loss of muscle mass. And because muscle burns more calories than fat, having less muscle can slow your basal metabolism over time, making you more prone to accumulate stubborn fat, particularly around your abdomen.

Hair loss

Testosterone itself isn’t directly linked to hair loss. However, your body’s sensitivity to a hormone called DHT, which is linked to testosterone, is. Here’s how it works.

There are two types of testosterone in the body: bound and free testosterone. Most of the testosterone in the body is bound to proteins in the blood, while only 2% to 5% of it is free. The free T (not the bound form) can be converted into dihydrotestosterone (DHT) in your body. DHT then binds to receptors on hair follicles on your scalp, face, and the rest of your body. Over time, this causes them to become thinner and shorter, and can eventually lead to hair loss.

For women, if your follicles are more sensitive to DHT, hair loss is more likely to start around menopause, when hormonal changes can make the effects of DHT more noticeable.

Low libido

Low T can reduce sex drive (libido) in both men and women. However, libido is influenced by many factors, including age, your relationship with your partner, what medications you’re taking, and your overall physical and mental health. So, if you’re experiencing low libido, low testosterone may be one of several possible causes rather than the only explanation. Yet, many studies have shown that testosterone replacement therapy (TRT) can improve libido in some men and women with low testosterone levels.

Erectile dysfunction

Low T can contribute to erectile dysfunction (ED), but it’s usually not the sole factor. While TRT has been shown to improve mild ED, it’s generally less effective for more severe cases. However, TRT has been shown to help improve erectile function in men who haven’t responded well to PDE-5 inhibitor medications like sildenafil and tadalafil.

Loss of muscle mass

This is one of the late signs of low T, and is also sometimes called muscle wasting. It happens because on the surface of muscle cells there are receptors for testosterone. When testosterone levels are low, muscle tissue may start to break down and gradually lose function.

Mood changes

Low T can contribute to difficulty concentrating, feeling irritable, anxious, depressed, and in some cases suicidal thoughts. You might find yourself more easily irritated by things others do or say, show a lower level of interest in activities you once enjoyed, or you may find it harder to cope with everyday stress.

Low motivation

Testosterone is involved in brain pathways linked to motivation, reward, and emotional regulation. So, if you have testosterone deficiency, you may find it harder to get started on tasks, feel less enthusiastic about work or hobbies, or notice that activities you once enjoyed no longer feel as rewarding. That said, these symptoms can also be caused by many other factors, including stress, poor sleep, and depression.

Brain fog

Brain fog is used to describe when you feel that your thinking isn’t as sharp as normal. You may also feel more forgetful or less able to concentrate.

Testosterone receptors are found throughout the brain, including areas that play a role in cognition and memory. Although testosterone’s effects on the brain are still incompletely understood, changes in testosterone levels can trigger difficulties with concentration, memory, and mental focus in some people.

Heightened anxiety or depression

Low T can affect your emotions as well, leading to feelings of sadness that can eventually develop into depression. Research, however, has found that both high and low testosterone levels were linked to depressive symptoms compared with men with normal testosterone levels. This means changes in mood are not always explained by testosterone levels alone.

Mental exhaustion

Mental exhaustion is not specific to low testosterone. Sleep problems, chronic stress, mental health conditions, and other health issues can all cause similar symptoms. That said, some people with low T describe feeling like everyday tasks require more effort, struggling to stay focused, or finding it harder to cope with stress.