Low testosterone results from a problem in the testicles or the brain and can cause low libido, muscle loss, and/or depressed mood. It is primarily treated with testosterone replacement therapy.
Testosterone is the best-known androgen (i.e., male sex hormone). It is secreted by the testicles and is responsible for the development and maintenance of secondary male characteristics (e.g., increased body and facial hair, enlarged larynx, deep voice, muscularity). Low testosterone (i.e., hypogonadism) results from the failure of the testicles (i.e., the gonads) to produce normal levels of testosterone due to a problem within the hypothalamic-pituitary-testicular (HPT) axis.
- Low sex drive
- Erectile dysfunction (i.e., the inability to get or keep an erection)
- Low sperm count
- Reduced muscle mass and strength and increased fat mass
- Low bone density (i.e., osteoporosis)
- Loss of body hair
- Gynaecomastia (i.e., enlargement of breast tissue)
- Sleep disturbances
- Reduced energy, depressed mood, and trouble concentrating
Testosterone levels are assessed using a blood test. The cutoff for low testosterone differs between organizations, but most define it as a total testosterone level of <231–275 ng/dL. Testosterone levels should be assessed early in the morning (between 7–11 a.m.) when peak levels occur, and in a fasted state. Two separate low testosterone measurements (preferably four weeks apart) along with clinical signs and symptoms of low testosterone are needed to be diagnosed with low testosterone.
Testosterone replacement therapy (TRT) is the primary treatment option for low testosterone and can be given as an oral pill, buccal tablet (which dissolves in the mouth), injection, nasal gel, topical gel, transdermal patch (worn on the skin), or implant. TRT appears to be safe, although there is limited data on long-term safety.
Each form of administration can cause unique adverse effects, but in general, TRT may cause erythrocytosis (as indicated by a hematocrit level > 54%), dyslipidemia, acne, oily skin, reduced sperm production, and/or growth of metastatic prostate cancer. Additionally, TRT is contraindicated for certain populations (e.g., people with a recent history of heart attack or stroke, heart failure, or prostate cancer).
A long list of supplements are marketed as testosterone boosters, but there is scant evidence to suggest that any of them affect testosterone levels. Some of the more popular options include saw-palmetto, ashwagandha, tribulus-terrestris, fenugreek, d-aspartic-acid, maca, horny-goat-weed, and boron.
In many men low testosterone is caused by reversible conditions, such as excess body fat and chronic disease (e.g., type-2-diabetes, metabolic-syndrome). Consequently, a hypocaloric diet is very effective for increasing testosterone levels in this population, whereas a hypocaloric diet seems to reduce testosterone levels in lean men.
In addition, it’s worth paying attention to dietary fat levels, because limited evidence suggests that low-fat diets (≤25% of energy intake) decrease testosterone levels compared to higher-fat diets (about 40% of energy intake).
Exercise — whether it’s aerobic exercise, high-intensity interval training, or resistance training — increases testosterone levels, especially when it’s included as part of a lifestyle intervention to reduce body weight. Exercise may also improve the effectiveness of TRT. Bariatric surgery is another effective method for increasing testosterone levels in men with obesity.
The cause of low testosterone is classified as either primary or secondary and further categorized as functional or organic. Primary hypogonadism originates from a problem in the testicles, while secondary hypogonadism indicates a problem in the hypothalamus or the pituitary gland, which are the parts of the brain that signal the testicles to produce testosterone.
Functional hypogonadism is caused by factors that suppress testosterone levels (e.g., medications, obesity, type 2 diabetes, aging, excessive exercise, malnutrition) but are potentially reversible, while organic hypogonadism is caused by a congenital, structural, or destructive condition (e.g., Klinefelter syndrome, Kallmann syndrome, hemochromatosis, inflammatory disease, injury to the testicles, traumatic brain injury, chemotherapy or radiation) that results in largely irreversible hypothalamic, pituitary, or testicular dysfunction.
Looking for a Supplement guide?Our Supplement Guides give you unbiased research-based recommendations that you can immediately apply to improve your health. Low Testosterone is related to the following Supplement Guides:
When it comes to increasing your testosterone, quality sleep, physical activity, and weight management come first. A few supplements can help sustain healthy testosterone levels, but most supplements marketed as testosterone boosters don't work, though some can make you believe they do by boosting your libido.
Testosterone is an androgen, a male sex hormone, though women need it too. In men, low testosterone has been associated with low libido and poor health outcomes, such as the development of metabolic syndrome. In men and women, low testosterone has been associated with depression.
Middle-aged and older men see their testosterone levels decrease by 0.4% to 1.6% per year, and many are the men who experience lower-than-average levels even in their 30s. Fortunately, quality sleep, physical activity, weight management, magnesium, zinc, and vitamin D can all help sustain healthy testosterone levels.
To optimize your testosterone levels, you don’t only need the proper amounts of vitamins and minerals; you also need to sleep well, exercise, and keep a healthy weight.
Lack of sleep causes numerous health issues. Notably, it decreases testosterone production and facilitates fat gain (and we’ll see that fat gain itself can impair testosterone production). Getting enough quality sleep is so important that we will be publishing an article on that soon.
2. Physical activity
Resistance training can raise testosterone levels for 15–30 minutes post-exercise. More importantly, it can benefit testosterone production in the long run by improving body composition and reducing insulin resistance.
Overtraining, however, is counterproductive. Prolonged endurance exercise especially can cause your testosterone to drop. Ensuring adequate recovery time will help you receive the full benefits of physical activity.
3. Weight management
Weight gain and the associated chronic diseases, such as cardiovascular disease and type 2 diabetes, are strongly linked to decreases in testosterone, particularly in middle-aged and older men.
If you gain weight (as fat), your testosterone production drops. Fortunately, if you lose weight, your testosterone production can climb back up.
Adapted from Grossmann and Matsumoto. J Clin Endocrinol Metab. 2017.
As this figure shows, observational studies have seen consistent results: in people who are overweight or obese, the greater the weight loss, the greater the testosterone increase.
These results have been echoed in clinical trials. A meta-analysis of 24 RCTs looked at weight loss caused by diet or bariatric surgery: In the diet studies, the average 9.8% weight loss was linked to a testosterone increase of 2.9 nmol/L (84 ng/dL). In the bariatric-surgery studies, the average 32% weight loss was linked to a testosterone increase of 8.7 nmol/L (251 ng/dL).
You need not lose huge amounts of weight to see a bump in testosterone levels, either: a 5% loss in weight can increase total testosterone by 2 nmol/L (58 ng/dL).
Quality sleep, physical activity, and weight management support healthy testosterone levels, and they’re synergistic: If you lack sleep, you find it harder to exercise and easier to gain fat. If you exercise, you find it easier to sleep and to keep a healthy weight. If your weight is healthy, you find it easier to exercise and easier to sleep.
If you want to know more about the lifestyle-testosterone connection, check out our infographic and article here.
Only a few supplements have been shown to benefit testosterone production. Among those, the evidence mostly supports vitamin D and zinc, followed by magnesium. Two caveats should be kept in mind, however:
Supplementing with a vitamin or mineral is likely to help you only if you suffer from a deficiency or an insufficiency in this vitamin or mineral.
Correcting a deficiency or an insufficiency is more likely to raise your testosterone levels if they are low.
1. Vitamin D
Vitamin D helps regulate testosterone levels. Ideally, you would produce all the vitamin D you need through sunlight exposure, but if you live far from the equator, have dark skin, or simply spend most of your time inside, you may need to complement your own production with the help of foods or supplements.
Serum 25(OH)D concentrations
In Canada and the United States, the Recommended Daily Allowance (RDA) for vitamin D falls between 400 and 800 IU (International Units). These amounts, which have been criticized as too low by some, are attainable from only a few food sources, which is why vitamin D has become a popular supplement.
* 40 IU = 1 mcg | ** Adequate intake (AI)
Reference: Institute of Medicine. Dietary Reference Intakes for Adequacy: Calcium and Vitamin D (chapter 5 in Dietary Reference Intakes for Calcium and Vitamin D. The National Academies Press. 2011. DOI:10.17226/13050)
Zinc deficiency can hinder testosterone production. Like magnesium, zinc is lost through sweat, so athletes and other people who sweat a lot are more likely to be deficient. Although dietary zinc is mostly found in animal products, zinc-rich foods include some grains and nuts.
* Adequate Intake (AI) Reference: Institute of Medicine. Zinc (chapter 12 in Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. The National Academies Press. 2001. DOI:10.17226/10026)
In males with low magnesium levels and low testosterone levels, an increase in magnesium intake can translate into an increase in testosterone production, both directly and (since one of magnesium’s functions in your body is to help convert vitamin D into its active form) indirectly.
While more common in the older population, magnesium deficiency isn’t unknown in younger people (notably athletes, since, link zinc, magnesium is lost through sweat). Yet getting your RDA should be easy: magnesium-rich foods are numerous and can fit all kinds of diets.
* Adequate intake (AI)
Reference: Institute of Medicine. Magnesium (chapter 6 in Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. The National Academies Press. 1997. )
If you still feel the need to supplement, keep in mind that supplemental magnesium is more likely than dietary magnesium to cause adverse effects, which is why the FDA fixed at 350 mg the Tolerable Upper Intake Level for magnesium supplementation in adults. Also, you may want to avoid magnesium oxide: it has poor bioavailability (rats absorbed only 15% in one study, and humans only 4% in another) and can cause intestinal discomfort and diarrhea.
Numerous products are advertised as testosterone boosters, but the vast majority don’t work, though some can make you believe they do by boosting your libido. Maca, for instance, can enhance libido without affecting testosterone.
Maybe the most popular “testosterone booster” is D-aspartic acid (DAA, or D-aspartate). DAA did increase testosterone levels in two studies, one that used 2.66 g/day and the other 3.12 g/day, but two later studies found no increase with 3 g/day, and the latest even noted a decrease with 6 g/day.
Eat a healthy, balanced diet, so as to avoid nutritional deficiencies. If your testosterone levels are low, pay attention to your intakes of vitamin D, zinc, and magnesium. Be skeptical of supplements marketed as testosterone boosters; there’s a good chance the only thing these supplements will boost is their manufacturers’ bottom lines.
The interventions discussed in this article will work best for men with low testosterone, but they can also help men with normal testosterone to sustain their levels, year after year.
Supplements can help, but they can’t replace a healthy lifestyle. In order to optimize your testosterone production, make sure you get enough quality sleep on a daily basis, incorporate some resistance training into your workout program, and monitor your weight.
Not all testosterone deficiencies can be fixed through lifestyle or supplement interventions. It may be prudent to speak with your doctor if the options discussed above do not yield sufficient results.
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