Total testosterone refers to the sum of the concentrations of protein-bound and unbound testosterone in the circulation and can be broken down into three categories:^[28]

• Tightly bound testosterone: About two-thirds of testosterone in the blood is bound to sex hormone binding globulin. It is not readily available for use by the body.
• Loosely bound testosterone: About one-third of testosterone in the blood is weakly bound to albumin. Once the bond is broken, the testosterone circulates as free testosterone in the body.
• Free testosterone: A small percentage of testosterone in the blood floats around freely. The body can readily use it, and the enzyme 5-alpha-reductase can convert it to DHT. The term bioavailable testosterone refers to the sum of loosely bound and free testosterone.

Assessing testosterone levels

DHEA, vitamin D, magnesium, and zinc have been seen to raise low testosterone levels. Few other supplements seem to help at all.

A few trials support the use of coleus-forskohlii, but its numerous potential adverse effects make it a risky proposition, especially for older people.

You might also have heard of d-aspartic-acid, but its promising initial trials were followed by several others that found that it didn’t increase testosterone.

Some other supplements, such as ginger and Eurycoma longifolia, might support testosterone levels only in infertile men (or in men with testicular damage).

Many other herbs, such as horny-goat-weed, have not even been studied in humans yet.

Finally, keep in mind that a supplement can benefit libido (as do maca and, according to a small number of studies, tribulus-terrestris), mood, or energy levels, yet not affect testosterone.

The evidence is mixed, but the preponderance of the evidence suggests that it’s unlikely that creatine will increase your testosterone levels.

Three randomized controlled trials conducted in healthy young men reported that supplementing with creatine for 1–3 weeks produced small increases in the levels of testosterone or dihydrotestosterone (DHT; a highly active androgen converted from testosterone).^[29][30][31] One of the 3 trials looked at the effect of creatine loading (25 grams/day for 1 week) followed by a maintenance phase (5 grams/day for 2 weeks) on testosterone and DHT in 20 young, healthy rugby players. Although no effect on testosterone was found, creatine increased the levels of DHT by 12 nanograms of DHT per deciliter of blood (ng/dL).^[29] The other 2 trials found that supplementation with creatine for 1 week in healthy, active young men increased the concentrations of testosterone by 57 ng/dL and 150 ng/dL.^[30][31]

Conversely, 10 other trials (involving a total of 218 participants) looking at the effect of supplemental creatine at daily doses of 3–25 grams on testosterone levels for up to 12 weeks have found no statistically significant effect.^{[32][33][34][29][35][36][37][38][39][40]} The participants in the majority of these trials were healthy, active young men. With regard to the form of creatine used, 9 trials administered creatine monohydrate, whereas 1 trial administered creatine malate. It’s worth noting that no trials have looked at the effect of creatine on testosterone in men with abnormally low testosterone levels.

Taken together, the available evidence suggests that supplementing with creatine is unlikely to increase testosterone levels, at least in young healthy men whose testosterone levels are within the normal range.

What is Ashwagandha?

Ashwagandha is a traditional Indian medicine (Ayurveda) that is known to be associated with male virility and vitality; a common supplement to recommend to men that are feeling past their prime and a traditional medicine with a surprisingly large amount of evidence overall. It does seem to have some anti-stress effects due to having the properties of an adaptogen.

Among the adaptogens and traditional medicine, however, ashwagandha is one of the few associated with masculinity. Since anything that can be named a testosterone booster gets praise faster than it gets research, many people are wondering whether ashwagandha can increase testosterone or whether it is overhyped.

What does it do?

When it comes to the topic of testosterone, the first study to find an effect was one in male rats where an increase was seen.^[41] When later tested in men suffering from some degree of infertility, improvements in sperm quality came alongside subtle boosts in testosterone around the range of 14-40%^[42] or 10-22%^[43].

While a promising supplement for fertility, it should be stated that supplements that can provide antioxidant support to the testicles are at times associated with an increase in testosterone in infertile but not otherwise fertile men (Vitamin E and CoQ10, for example). Other profertility drugs, such as D-Aspartic acid, are commonly confused with testosterone boosting supplements when the benefits seen in infertile men are erroneously extrapolated.

However, despite all that, at least one study has found a mild increase in testosterone in otherwise healthy men subject to weight training by 15%.^[44] It is not likely that a 15% increase in testosterone will result in major changes in muscularity, but an earnest increase in testosterone in healthy young men by a dietary supplement is quite rare.

While it is more likely a profertility agent, we cannot deny a possibility that ashwagandha could increase testosterone. However, evidence at this time is quite limited.

Resistance training can temporarily raise testosterone levels for 15–30 minutes post-exercise.^[16][17] More importantly, it can benefit testosterone production in the long run by improving body composition and reducing insulin resistance.^[16]

Overtraining, however, is counterproductive. Prolonged endurance exercise especially can cause your testosterone to drop.^[18][19] Ensuring adequate recovery time will help you receive the full benefits of physical activity.

In general, serum testosterone rises immediately following resistance training in men, but returns to baseline, or even below baseline, after about 30 minutes.^[20] In women, some studies have also found short-term increases in serum testosterone, but others haven’t, so the results are more equivocal.

Fat gain and the associated increase in chronic disease risk, such as cardiovascular disease and type 2 diabetes, are strongly linked to decreases in testosterone, particularly in middle-aged and older men.^[21][22][23] If you gain weight (as fat), your testosterone production drops. Fortunately, if you lose weight, your testosterone production can climb back up.

Effect of weight loss on testosterone levels

Reference: Grossmann and Matsumoto. J Clin Endocrinol Metab. 2017.^[8]

A meta-analysis of 24 RCTs looked at weight loss caused by diet or bariatric surgery.^[15] 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 may increase total testosterone by 2 nmol/L (58 ng/dL).^[24]

Middle-aged^[25] and older^[26] men see their total testosterone levels decrease by 0.4% to 1.6% per year, many of whom had lower-than-average levels even in their 30s.^[27] Bioavailable testosterone decreases by about 2–3% a year.^[25]

Those numbers can be pretty misleading, though. Men approaching middle age tend to exercise a lot less and eat a lot worse. So it’s hard to say what a “natural” decline in testosterone looks like on a population-wide basis.

It’s kind of like saying muscle mass decreases 1–2% a year once you hit middle age. That decrease can have a lot to do with more time spent on work and family and less time spent trying to get ripped.

Several drugs and drug classes may decrease testosterone levels. If you are on any of the medications below and are concerned about your T levels, consult your physician. Do not stop the treatment without professional medical input.

• Antiandrogens (e.g., cyproterone, bicalutamide, flutamide, spironolactone)
• Chemotherapy (e.g., alkylating agents)
• Chronic anabolic steroid use (particularly when high doses are used)
• Glucocorticoids
• Ketoconazole
• Luteinizing hormone-releasing hormone agonists (aka LHRH analogs or GnRH agonists)
• Opioids
• Radiation therapy (total body or pelvis in particular)
• Selective serotonin reuptake inhibitors (SSRIs)
• Suramin

What does male orgasm result in, biochemically?

Higher serum testosterone levels are seen during abstinence (3 weeks in cited study).^[45] Non-significant Luteinizing Hormone increases have also been noted.^[45] The difference between abstinence and non-abstinence appears to be about 0.5ng/ml when averaged out.^[45]

Although higher testosterone levels are seen with abstinence,^[46] orgasm does not acutely affect testosterone levels in the blood.^[45] Although there is not much evidence for the spike in testosterone during abstinence, there does not appear to be counter evidence at the moment; it is an understudied topic.

Orgasm can cause a significant spike in prolactin levels (approximately 10 to 15ng/ml) immediately after and upwards to 10-20 minutes later, at which it starts to decline.^[45][47] This spike is dependent on ejaculation, and does not occur under non-orgasmic arousal.^[48] This spike may serve to suppress further sexual desires.^[49][50]

Various cardiovascular parameters, such as heart rate and catecholamine (adrenaline, noradrenaline) levels are increased during sex/masturbation and orgasm.^[47] Some measure of increase is seen during arousal.^[48]

Other various markers, such as Vasopressin and Follicle-Stimulating Hormone (FSH) remain unchanged.^[48]

Biochemical markers do not differ significantly when comparing orgasm after abstinence and orgasm without abstinence.^[45] Slight increases were seen in heart rate and catecholamine (adrenaline) levels, but may be due to self-reported higher arousal on average.

How is testosterone related to orgasm?

Testosterone has minimal interactions with orgasm, but is seen as a positive regulator of sexual desire or libido alongside dopamine.^[51][52] Agents that increase dopamine levels or act like dopamine can increase frequency of erections and subjective sexual arousal.^[53][54] Prolactin is the opposite here, and is a negative regulator of sexual appetite.

The actual ejaculatory process and erection process is mediated by serotonin and Nitric Oxide, as well as various mechanical contractions in the pelvic and penile region.^[51] Drugs or supplements that interfere with serotonin reuptake (such as SSRIs) can reduce the orgasm response, and may be useful in treating premature ejaculation.^[55][56]

Dopamine is reduced temporarily as prolactin rises, as the two can be seen as antagonistic of each other. Levels shortly normalize.^[57] The post-orgasm 'orgasmic state' of euphoria is mediated by prolactin and mimicked by ecstasy.^[58]

Ejaculation does not impact your testosterone levels.

Testosterone is an androgen, a male sex hormone, though women need it too. In men, low testosterone has been associated with low libido^[59] and poor health outcomes, such as the development of metabolic syndrome.^[60] In men and women, low testosterone has been associated with depression.^[61][62]

Middle-aged^[25] and older^[26] 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.^[27] Fortunately, quality sleep, physical activity, weight management, magnesium, zinc, and vitamin D can all help sustain healthy testosterone levels.

Lifestyle

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.

1. Sleep

Lack of sleep causes numerous health issues. Notably, it decreases testosterone production^{[63][64][65][66][67]} and facilitates fat gain^[68] (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.^[16][17] More importantly, it can benefit testosterone production in the long run by improving body composition and reducing insulin resistance.^[16]

Overtraining, however, is counterproductive. Prolonged endurance exercise especially can cause your testosterone to drop.^[18][19] 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,^[21][22][23] 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.^[8]

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.^[21]

These results have been echoed in clinical trials. A meta-analysis of 24 RCTs looked at weight loss caused by diet or bariatric surgery:^[15] 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).^[24]

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.

Supplements

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.^[69][70] 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).^[71] These amounts, which have been criticized as too low by some,^[72][73] 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)

2. Zinc

Zinc deficiency can hinder testosterone production.^[74][75] Like magnesium, zinc is lost through sweat,^[76] 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)

Consuming much more than your RDA^[77] can be harmful. In the short term, high doses can cause nausea^[78] and vomiting.^[79] In the long term, they can lead to a copper deficiency.^[80][81]

3. Magnesium

In males with low magnesium levels and low testosterone levels, an increase in magnesium intake can translate into an increase in testosterone production,^[82] both directly and (since one of magnesium’s functions in your body is to help convert vitamin D into its active form^[83]) indirectly.

While more common in the older population,^[84] magnesium deficiency isn’t unknown in younger people (notably athletes,^[85] since, link zinc, magnesium is lost through sweat^[76][86][87]). 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. ^[88])

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,^[89] and humans only 4% in another^[90]) and can cause intestinal discomfort and diarrhea.

Overhyped supplements

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.^{[91][92][93][94]}

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^[95] and the other 3.12 g/day,^[96] but two later studies found no increase with 3 g/day,^[97][98] and the latest even noted a decrease with 6 g/day.^[97]

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.

Bottom line

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.

Try to get enough vitamin D, zinc, and magnesium through your diet. However, if dietary changes prove insufficient, supplementation can help make up the difference.

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.