Low Testosterone Symptoms in Men: Signs, Causes, Testing and Treatment

Low testosterone, also called androgen deficiency or male hypogonadism, gets a lot of attention online. Real androgen deficiency that needs treatment affects about 5 in every 1000 men,⁶ but many more men have symptoms that could be low testosterone or something else. Here's what the evidence says about the signs, the tests and what actually helps.

What does testosterone do?

Testosterone is the main male sex hormone (androgen). It's made mostly in the testes, and its production is controlled by two small structures in the brain: the hypothalamus and the pituitary gland. Testosterone is needed for:

• starting and completing puberty
• bone and muscle development
• body and facial hair growth
• the deeper adult male voice
• sex drive (libido) and erections
• sperm production

What are the symptoms of low testosterone?

Symptoms can be subtle and often overlap with other health problems. Common signs include:⁷

• Sexual: reduced libido and erection problems
• Energy and mood: low energy, low mood and poor concentration
• Sleep: poor sleep, and sometimes hot flushes
• Body changes: more body fat, less muscle, swollen or tender breasts, and less body hair growth

Because tiredness, low mood and low libido have many possible causes, including stress, poor sleep, depression and other medical conditions, these symptoms are a reason to get checked, not proof of low testosterone.²

What causes low testosterone?

True androgen deficiency is caused by a problem with the testes, or with the hypothalamus or pituitary gland that signal the testes to make testosterone.¹

• Testicular causes: Klinefelter syndrome, undescended testes, injury or surgery, infection such as mumps, and chemotherapy or radiotherapy.
• Hypothalamus or pituitary causes: a benign pituitary tumour, Kallmann syndrome and other genetic conditions, and iron overload (haemochromatosis).

Lower testosterone is also linked with obesity, metabolic syndrome and type 2 diabetes, and with taking opioids or corticosteroids. In these cases the drop may be partly reversible, and it isn't clear that testosterone treatment helps.¹ Anabolic steroid use can also shut down the body's own testosterone production.

How is low testosterone diagnosed?

Low testosterone is diagnosed with a blood test, taken early in the morning while fasting, when levels are highest. Because levels vary, a low result needs to be confirmed with a second morning test on a different day.²⁶ Your doctor will usually also check luteinising hormone (LH) and follicle-stimulating hormone (FSH), which show whether the problem starts in the testes or the brain.¹

Saliva and urine tests, and home "hormone kits", aren't used to diagnose androgen deficiency. A diagnosis needs both symptoms and consistently low blood levels.²

How is low testosterone treated?

If you have true androgen deficiency, testosterone replacement therapy (TRT) is recommended regardless of age.¹ It's prescribed by a doctor as a gel or cream, injection or capsule, and needs regular monitoring. In Australia, PBS-subsidised testosterone requires confirmed deficiency on blood tests and treatment by, or in consultation with, a specialist such as an endocrinologist or urologist.⁶

If you want children, tell your doctor. Testosterone therapy suppresses sperm production, so it shouldn't be started in men planning a family soon.²⁶ Talk through the benefits and possible side effects with your doctor before starting.

How can you increase testosterone naturally?

Lifestyle changes won't fix testicular or pituitary disease, but they matter a lot when low testosterone is linked with excess weight or type 2 diabetes.

• Lose excess weight: in a meta-analysis of 24 studies, weight loss was linked with higher testosterone, and the more weight lost, the bigger the rise.³ Managing type 2 diabetes can help too.⁷
• Don't go very low-fat: men on low-fat diets had lower testosterone than men on higher-fat diets in intervention studies.⁴ Choose mostly unsaturated fats such as olive oil, avocado, nuts, seeds and oily fish.
• Stay active: regular exercise, including strength training, supports weight loss, muscle and blood glucose control.
• Look after sleep and stress: poor sleep and low mood are common symptoms, and improving them helps how you feel whatever your testosterone level.

Do testosterone booster supplements work?

Mostly no. A systematic review found that tribulus, one of the most popular "booster" herbs, doesn't appear to raise testosterone in humans, and that marketing claims are unsubstantiated.⁵ If you think you could be low in a nutrient such as vitamin D or zinc, ask your practitioner to check your levels before you supplement.

How an Accredited Practising Dietitian can help

An APD can help you lose weight steadily without crash dieting, build meals with enough protein and healthy fats, and support blood glucose control if you have type 2 diabetes. That work can sit alongside any medical treatment your doctor recommends.

Frequently asked questions

What are the first signs of low testosterone?

Low sex drive, erection problems, tiredness and low mood are often the first things men notice. These can have other causes, so a blood test is needed to confirm it.

What time of day should testosterone be tested?

Early in the morning while fasting, when levels are highest. A low result should be repeated on another morning to confirm it.

Can losing weight increase testosterone?

Yes. In men with excess weight, weight loss is linked with higher testosterone, and greater weight loss is linked with a bigger rise.

Does tribulus increase testosterone?

The evidence suggests it doesn't raise testosterone in humans, and marketing claims for it are unsubstantiated.

Does testosterone therapy affect fertility?

Yes. Testosterone therapy suppresses sperm production, so it shouldn't be started if you're planning to have children soon.

Is low testosterone just part of ageing?

Testosterone falls by about 1% a year with age, but this gradual decline on its own isn't considered androgen deficiency.

References

Research (PubMed)

1. Yeap BB, Grossmann M, McLachlan RI, et al. Endocrine Society of Australia position statement on male hypogonadism (part 1): assessment and indications for testosterone therapy. Med J Aust. 2016;205(4):173–178. PubMed 27510348
2. Bhasin S, Brito JP, Cunningham GR, et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2018;103(5):1715–1744. PubMed 29562364
3. Corona G, Rastrelli G, Monami M, et al. Body weight loss reverts obesity-associated hypogonadotropic hypogonadism: a systematic review and meta-analysis. Eur J Endocrinol. 2013;168(6):829–843. PubMed 23482592
4. Whittaker J, Wu K. Low-fat diets and testosterone in men: systematic review and meta-analysis of intervention studies. J Steroid Biochem Mol Biol. 2021;210:105878. PubMed 33741447
5. Qureshi A, Naughton DP, Petroczi A. A systematic review on the herbal extract Tribulus terrestris and the roots of its putative aphrodisiac and performance enhancing effect. J Diet Suppl. 2014;11(1):64–79. PubMed 24559105

Australian guidelines

6. Healthy Male (Andrology Australia). Androgen deficiency: clinical summary guide. 2021. View source
7. healthdirect Australia. Testosterone. Reviewed September 2024. View source

This article is general information and isn't a substitute for personalised advice. Speak to your practitioner about your situation.