Tiredness, a flat mood and a weaker sex drive can all point to low testosterone, yet each has many other explanations. We explain how to sort one from the other and what a test involves.
Low sex drive, fewer morning erections and erectile problems are the most specific signs of low testosterone. Fatigue, low mood and muscle loss often come with them. These symptoms overlap with many other conditions, so a diagnosis of low T requires matching symptoms plus two early-morning blood tests below about 300 ng/dL. Supplements can't correct a true deficiency. Get tested by a doctor first.
Low testosterone seldom announces itself with a single clear symptom. More often a group of changes creeps in gradually, and many men blame stress, age or a hectic year. The Cleveland Clinic says the sexual symptoms are the most specific, and the others are more general.
Mayo Clinic reports that reduced sex drive, low energy and depression commonly show up first. Muscle loss, less body hair and bone loss tend to follow later.
Nearly every item above has other frequent causes. Depression, ongoing stress, poor sleep, thyroid problems, heavy drinking, relationship strain and many medications can also bring on tiredness, low libido and a low mood. Erectile problems often trace back to blood vessel health, diabetes or blood pressure medicines.
The American Urological Association (AUA) says so plainly in its testosterone deficiency guideline. The symptoms are nonspecific and may stem from chronic fatigue, chronic stress or depression. So symptoms can't establish low T alone, and neither can a blood test alone. Both are needed.
Levels do slide with age. The Cleveland Clinic estimates a fall of about 1% per year from the late 30s onward. In most men that gradual change causes no trouble by itself, and many older men stay comfortably within the normal range.
Real deficiency, called hypogonadism in medical terms, is a separate matter. The AUA defines it as low testosterone production together with symptoms. Having a number a little under what you had at 25 doesn't qualify. Neither does feeling worn out at 50 with a normal blood result.
| Age-related decline | Testosterone deficiency | |
|---|---|---|
| Blood levels | Slowly declining, normally still within the usual range | Repeatedly under the lab's cutoff on morning retests |
| Symptoms | Frequently nothing, or mild ones that other factors explain | Symptoms and physical signs consistent with the low levels |
| What usually happens next | Lifestyle changes: sleep, weight, exercise and alcohol | Identify the cause, then talk through treatment with a doctor |
The test itself is a simple blood draw, but timing and details matter. One afternoon sample taken after a poor night's sleep can easily be misleading.
Levels are highest in the morning, so blood is typically taken between about 7 and 10 a.m., says MedlinePlus. The AUA guideline uses a total testosterone below 300 ng/dL as a reasonable cutoff. It also says the diagnosis should rest on two total testosterone readings taken on separate early mornings. The Endocrine Society guideline agrees that a low result should be confirmed with a repeat morning fasting total testosterone test.
The Cleveland Clinic notes that even a short illness can lower testosterone for a while. If you were sick or run down on the day of the draw, ask your doctor whether to repeat it.
Most of the testosterone in blood is attached to proteins, chiefly sex hormone-binding globulin (SHBG). A total testosterone test counts bound and unbound hormone together and is the usual first test. A free testosterone test counts only the portion that isn't attached. The Endocrine Society says hypogonadism can be diagnosed from low total and/or free testosterone, with the free level checked when indicated. If your total is borderline, your doctor may add free testosterone or SHBG.
A low result raises the question of why. The AUA recommends measuring luteinizing hormone (LH) in men with low testosterone. The Endocrine Society recommends LH and follicle-stimulating hormone (FSH), which help tell two main types apart:
Your doctor might also test prolactin, because a high level can hint at a pituitary problem. The AUA recommends this in certain cases.
Few men with low T symptoms have an injured testicle or a pituitary tumor. The Cleveland Clinic says most cases are tied to obesity or diabetes. Contributors you might see include:
That's why the cause should be found before anyone tries to move the number. Treating sleep apnea, losing weight or switching a medication can sometimes raise levels without hormone therapy.
Book a visit if you have several of the symptoms above for more than a few weeks, particularly low libido, fewer morning erections or erectile problems. Don't wait if you notice any of these:
Ask for a morning test, and expect a second one if the first comes back low. Testosterone therapy for a diagnosed deficiency is a prescription treatment, and it has real trade-offs. Because it can suppress sperm production, the AUA advises against prescribing it for men who are actively trying to conceive. During treatment your doctor should also check blood counts and monitor your levels.
Over-the-counter "testosterone boosters" can't repair clinical hypogonadism. If the testicles or pituitary aren't working as they should, no herb or mineral takes over that job. Choosing a supplement over a test can also hold up the discovery of something important, like sleep apnea, diabetes or a pituitary problem.
Evidence for these products is thin. A 2019 analysis of 50 testosterone booster products, published in the World Journal of Men's Health, found that 90% claimed to raise testosterone. Only about a quarter of the 109 unique ingredients, though, had published data showing a rise, and some products went beyond safe upper limits for zinc, niacin (vitamin B3) or magnesium. The researchers examined labels and published research. They did not test how the products worked in people.
A supplement has a narrower role than the marketing suggests. Fixing a genuine shortfall, such as low vitamin D or zinc, may help men whose levels are low because of it. Our vitamin D and testosterone guide sums up what the trials found. If your levels are normal or borderline-normal and you want to support general health, sleep, weight loss and strength training come first, and a supplement is at best a small extra.
Still want to try one? Our advice on choosing a testosterone supplement helps you check doses and ingredients against the research, and our testosterone boosters for men over 40 roundup is there if age matters to you. Tell your doctor what you take, especially if you use blood thinners, diabetes or blood pressure medicines, or have a prostate condition.
The symptoms of low testosterone are real, but stress, depression, poor sleep and many other conditions produce the same ones. To find out, you need two early-morning blood tests and a doctor's review of your symptoms and likely causes. Weight, sleep apnea, diabetes and medications are common contributors that can often be addressed. Supplements may have a minor role where levels are borderline or a nutrient gap is proven. They don't replace a diagnosis, or prescription treatment when deficiency is genuine.