Magnesium supplements generally come in the form of magnesium salts bound to another element or amino acid. Some of the main forms of magnesium include magnesium oxide, magnesium hydroxide (the commercial product Milk of Magnesia), magnesium citrate, magnesium lactate, magnesium gluconate, magnesium aspartate, magnesium glycinate, magnesium orotate, magnesium threonate, and magnesium sulfate (Epsom salt).

Some forms of magnesium (such as magnesium hydroxide and magnesium oxide) are typically used for laxative purposes. Magnesium citrate is the most commonly used form of supplemental magnesium because of its high bioavailability and relatively low cost. Magnesium threonate has been investigated for its effects on increasing brain magnesium levels, which may benefit learning and memory,^[50][51] although research to date has only been conducted in animal models (rats).

In other words, different forms of magnesium are used for different specific purposes.

A variety of plant and animal foods are good sources of magnesium, including the following:

Dark leafy green vegetables: kale, spinach, collard greens, turnip greens, mustard greens

Nuts and seeds: cashews, almonds, pumpkin seeds, chia seeds, flaxseed

Beans and legumes: lentils, chickpeas, peas, soybeans, black beans, kidney beans, peanuts

Whole grains: rice, oats, whole-wheat bread, quinoa, buckwheat, barley

Fruits and vegetables: bananas, avocados, potatoes, raisins, apples, carrots, broccoli

Meat and fish: salmon, halibut, chicken, lean ground beef

Other dietary sources of magnesium include fortified bread and breakfast cereals, milk and yogurt products, and, serendipitously, dark chocolate.^[4]

Of note, approximately 30%–40% of the dietary magnesium we eat is absorbed by the body when a mixed (i.e., omnivorous) diet is consumed.^{[52][5][7][6]} The consumption of certain foods( i.e., low-oxalate leafy green vegetables) also appears to enhance magnesium bioavailability compared to magnesium obtained from eating whole grains or oxalate-rich vegetables, which contain compounds that interfere with magnesium absorption.^[53][54][55]

Due to its actions as an N-methyl-D-aspartate (NMDA) antagonist and a gamma-aminobutyric acid (GABA) agonist, magnesium is hypothesized to help regulate the sleep/wake cycle and thereby promote healthy sleep.^[56][57] For this reason, magnesium is often promoted as a sleep-enhancing supplement, and some people use magnesium to treat insomnia and improve sleep quality and/or sleep duration. However, there is surprisingly little evidence to support its use.

Some evidence from animal studies shows that higher magnesium levels in specific sites in the brain are associated with better sleep quality.^[58] Some evidence from observational studies in humans finds low serum magnesium concentrations in people with obstructive sleep apnea, a sleep disorder associated with sleep disturbances.^[59] Meanwhile, other evidence from observational studies shows that higher magnesium intake is associated with better sleep quality.^[60] However, these lines of evidence do not prove that magnesium helps with sleep.

Unfortunately, very few randomized controlled trials have assessed the effect of magnesium on sleep quality or sleep duration, and their outcomes are mixed.^[61][62][63] Consequently, although recent systematic reviews and meta-analyses have found that supplemental magnesium may reduce sleep latency by approximately 17 minutes, they conclude that the quality of current evidence is insufficient to make well-informed recommendations and that larger randomized controlled trials are needed to remedy that issue.^[56][64]

Supplementation with magnesium during pregnancy can have health benefits for both mother and baby; however, the quality of evidence is mixed, and large, well‐designed randomized controlled trials are needed to draw firm conclusions.^{[65][66][67][12][68][49][69][28][70]}

Importantly, adverse effects of magnesium are rare, and supplementation with magnesium before or during pregnancy appears to be safe for mother and baby.^{[65][66][69][70]} That said, women who are pregnant or planning to become pregnant should consult their doctor for advice before starting to supplement with magnesium.

Observational studies have found that serum magnesium concentrations are not different between people with and without generalized anxiety disorder^[71] and that serum magnesium concentrations are not correlated with self-reported levels of anxiety.^[72][73] Some observational studies have found an association between a greater dietary magnesium intake and lower odds of anxiety,^[74] but other studies do not confirm that finding.^[75][76]

Some clinical trials have compared magnesium to magnesium + pyridoxine (vitamin b6) and found a post-trial decrease in self-reported anxiety and/or stress levels in people in the magnesium group.^[77][78][79] However, conclusions concerning the direct effect of magnesium cannot be made from studies lacking a control group who did not take magnesium. Fortunately, there are some randomized controlled trials comparing supplementation with magnesium to a placebo. These studies have mixed outcomes that showed a possible, but weak, effect of magnesium on anxiety.^{[61][80][81][32][82][83]} However, the overall quality of the evidence is low, and high-quality randomized controlled trials are needed.^[82][83]

Some people take Milk of Magnesia, which contains magnesium hydroxide, to alleviate constipation. While some studies find a benefit,^{[84][85][86][87]} its overall efficacy is unclear due to a lack of high-quality research.^[88][89] Other studies have found that magnesium oxide might also improve constipation;^[90][91][92] similarly, however, further high-quality research is needed to draw firm conclusions concerning its efficacy.

It’s important to note that Milk of Magnesia has several drug interactions (e.g., aspirin, prednisone, cholecalciferol (vitamin D3)); therefore, people who use medications should consult their doctor before using Milk of Magnesia/magnesium hydroxide. Furthermore, Milk of Magnesia interacts with several conditions. People with intestinal disorders, kidney problems, or inflammatory bowel disease should also consult their doctor before using Milk of Magnesia/magnesium hydroxide.

Large cross-sectional studies have shown that a higher systolic blood pressure in adults who experience hypertensive crises (sudden and severe rises in blood pressure) is associated with a higher serum magnesium concentration.^[93] However, in healthy children and adults without hypertensive crises, higher blood pressure is associated with a lower serum magnesium concentration.^[94][95][96] Furthermore, children with lower serum magnesium concentrations are more likely to have high blood pressure,^[94][95] and serum magnesium concentrations are lower in adults with high blood pressure (hypertension) compared to healthy adults.^[96]

Other types of observational studies show that a lower systolic blood pressure is associated with a high dietary magnesium intake^[96][97] and that people with a high dietary magnesium intake are less likely to have high blood pressure (hypertension).^[98] However, not all studies confirm this relationship,^[99] and these types of studies have limitations because magnesium intake is estimated from self-reported diet intake surveys. Consequently, they do not reveal whether supplementation with magnesium helps with blood pressure.

Meta-analyses of randomized controlled trials show that supplementation with magnesium can have a small but meaningful effect on lowering blood pressure in people with high blood pressure,^{[100][23][101][102]} prediabetes,^[24] or type 2 diabetes.^[26][25] However, there is large between-trial variability in the effect size, and the efficacy of magnesium on blood pressure appears greatest in people with low serum magnesium concentrations.^[11][23] That said, many randomized controlled trials do not report baseline serum magnesium concentrations, so this relationship requires further exploration.

ZMA is a proprietary blend of Zinc bound to monomethionine, Magnesium bound to aspartate, and the vitamin B6 (Pyridoxine). It is sometimes reported to give users 'weird, vivid dreams'.

This claim has not been investigated much, but a pilot study^[41] suggests that a dose of 250mg pyridoxine can alter dream perception in college aged men, through a hypothesized increased conversion of tryptophan to serotonin. This dose of B6, however, is much higher than that occurring in ZMA products; which tends to range in the 10-50mg range and usually at the lower end.

One other study has reported synergism between B6 and Magnesium in regards to anxiety reduction, when the subjects were women experiencing PMS;^[42] it is theoretically possible that the ZMA formulation enhances the actions of pyridoxine allowing the previous research's results to be relevant.

It’s a widely held belief that imbalances in electrolytes — in particular magnesium — may be involved in the etiology of muscle cramps — sudden involuntary contractions of one or more muscles that lead to sharp pains. However, the theory that muscle cramps are related to electrolyte or water imbalances has been questioned, although some evidence suggests that exercise-associated muscle cramps may have their origin in excessive losses of water and sodium during exercise.^[43]

The idea that low magnesium levels play a role in muscle cramping comes from evidence that reduced magnesium levels are correlated to higher rates of muscle cramping during pregnancy^[44][45] and in people who experience leg cramps at night.^[46] Severe magnesium deficiency has also been associated with a higher incidence of muscle pain and cramping.^[47][48]

However, a meta-analysis published in 2020 concluded that it is unlikely that magnesium supplementation in any form can reduce idiopathic nocturnal or exercise-induced muscle cramps. The available evidence on a reduction in pregnancy-associated muscle cramps was conflicting.^[49]

Testosterone is an androgen, a male sex hormone, though women need it too. In men, low testosterone has been associated with low libido^[103] and poor health outcomes, such as the development of metabolic syndrome.^[104] In men and women, low testosterone has been associated with depression.^[105][106]

Middle-aged^[107] and older^[108] 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.^[109] 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^{[110][111][112][113][114]} and facilitates fat gain^[115] (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.^[116][117] More importantly, it can benefit testosterone production in the long run by improving body composition and reducing insulin resistance.^[116]

Overtraining, however, is counterproductive. Prolonged endurance exercise especially can cause your testosterone to drop.^[118][119] 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,^{[120][121][122]} 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.^[123]

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.^[120]

These results have been echoed in clinical trials. A meta-analysis of 24 RCTs looked at weight loss caused by diet or bariatric surgery:^[124] 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).^[125]

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.^[126][127] 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.

In Canada and the United States, the Recommended Daily Allowance (RDA) for vitamin D falls between 400 and 800 IU (International Units).^[128] These amounts, which have been criticized as too low by some,^[129][130] 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.^[131][132] Like magnesium, zinc is lost through sweat,^[133] 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^[134] can be harmful. In the short term, high doses can cause nausea^[135] and vomiting.^[136] In the long term, they can lead to a copper deficiency.^[137][138]

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,^[139] both directly and (since one of magnesium’s functions in your body is to help convert vitamin D into its active form^[140]) indirectly.

While more common in the older population,^[141] magnesium deficiency isn’t unknown in younger people (notably athletes,^[142] since, link zinc, magnesium is lost through sweat^{[133][143][144]}). 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. ^[35])

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,^[145] and humans only 4% in another^[146]) 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.^{[147][148][149][150]}

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^[151] and the other 3.12 g/day,^[152] but two later studies found no increase with 3 g/day,^[153][154] and the latest even noted a decrease with 6 g/day.^[153]

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.