Best Magnesium Supplement for Men: ZMA vs Glycinate and 8 Labels Compared

Reviewed by Sarah Law, Dip CNM, Naturopathic Nutritionist

Published 3 November 2026. Every figure for the other brands comes from the brand's own product page or supplement facts panel, read on 3 November 2026. Our own figures come from our printed labels, and our prices were read live from our UK and US stores on 6 November 2026.

Magnesium Glycinate: unbuffered bisglycinate, 303 mg elemental magnesium per 4 capsules, 240 vegan capsules, made in the UK and third-party tested.

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Best magnesium supplements for men compared: the label table

The table compares the daily serving of eight magnesium supplements men commonly buy in the UK and the US, as each brand defines it (for the US ZMA, the men's dose of three capsules). Every figure for the other brands was read from the brand's own product page or supplement facts panel on 3 November 2026; prices are each brand's one-off price for the pack named, before subscription discounts, and two UK prices were sale prices on the day. Our two rows come from our printed labels and live store prices. UK NRV is the 375 mg nutrient reference value used on UK and EU labels.

Sources: Optimum Nutrition ZMA and Magnesium Glycinate supplement facts panels on optimumnutrition.com (US store); thorne.com; doctorsbest.com; myprotein.com (UK store), all read 3 November 2026. Price per serving is the pack price divided by the servings each brand states. Love Life Supplements figures from labels Mag_Bis_P32648_v10 and MagnesiumSEVEN_175x70_v2; prices from our UK and US stores on 6 November 2026.^19,20

Two things stand out. First, the cheapest products per serving are also the lowest dose: the Myprotein tablet costs 8p but gives 113 mg, so reaching our 303 mg would take nearly three tablets. Second, the product sold most directly to men, the US ZMA, is the one that goes furthest over the reference limits, on both magnesium and zinc.

Which magnesium is best for men?

Glycinate is the best everyday magnesium for most men: it is well absorbed, it rarely loosens stools at normal doses, and a capsule makes the dose easy to repeat. The right pick then depends on what you want it for and what else you already take.

Magnesium contributes to normal muscle function, normal protein synthesis, electrolyte balance, normal energy-yielding metabolism, normal psychological function and the reduction of tiredness and fatigue.¹⁵ Those are the authorised claims, and they apply whichever well-absorbed form you choose. If you want the full form-by-form comparison, our magnesium glycinate vs citrate vs oxide guide covers absorption in detail, and our best magnesium supplement for women page compares nine more labels.

How much magnesium does a man need a day?

A man aged 19 to 64 needs 300 mg of magnesium a day on the NHS figure, and 400 mg (ages 19 to 30) or 420 mg (31 and over) on the US NIH Recommended Dietary Allowance.^13,14 These are totals from food, drink and supplements. The two systems set the figure differently, so the US number is higher, but both expect most of it to come from food such as nuts, seeds, beans, wholegrains and leafy greens.

Sources: NHS vitamins and minerals guidance; UK food information regulation Annex XIII; NIH Office of Dietary Supplements magnesium fact sheet; US National Academies Dietary Reference Intakes for magnesium (1997) and zinc (2001).^13,14,16,17

Many men fall short on food alone. In the US, almost half (48%) of the population ate less than the required amount of magnesium from food in 2005 to 2006, and the NIH names men aged 71 and over among the groups at highest risk of low intakes.^6,13 That is the case for a moderate supplement: it tops up a shortfall. It does not mean more is better. High doses of magnesium from supplements can cause diarrhoea, nausea and abdominal cramping, which is why the US limit applies to supplements and medicines rather than food.¹³ Our how much magnesium glycinate per day guide works through doses by body size and goal.

Count every product. A man taking our Magnesium Glycinate (303 mg) and a serving of our Ultimate Electrolytes (150 mg magnesium from 1,000 mg magnesium malate) on the same day gets 453 mg from supplements, above the US limit. On those days, two capsules of glycinate (about 150 mg) instead of four keeps the total near 300 mg.

"When men come to me wanting to add magnesium, I ask them to list what they already take first: the electrolyte sachet, the ZMA before bed, the multivitamin. It is common to find two or three products all containing magnesium or zinc. One well-chosen magnesium at the label dose, alongside a diet with nuts, seeds, beans and greens, is usually all that is needed."

Sarah Law, Naturopathic Nutritionist | Optimised Female

ZMA vs magnesium glycinate: which should men take?

For most men, magnesium glycinate is the better choice, because it gives a clear magnesium dose without adding zinc you may not need. ZMA is a combination of zinc, magnesium and vitamin B6, sold mainly to men who train, usually taken at bedtime.

The evidence for ZMA itself is limited. The one double-blind trial of a commercial ZMA in trained men gave it to 42 resistance-trained men for 8 weeks of standardised training. Serum zinc rose slightly (not significantly), but there were no differences from placebo in anabolic or catabolic hormones, body composition, bench or leg press strength, muscular endurance or anaerobic capacity. The authors concluded that ZMA did not appear to enhance training adaptations.³

The bigger issue is dose, and it differs sharply between markets:

• US Optimum Nutrition ZMA, men's dose (3 capsules): 435 mg magnesium from aspartate and oxide, 28 mg zinc, 10 mg vitamin B6. That is above the US 350 mg supplement limit for magnesium and above the NHS 25 mg guidance for zinc, though under the US zinc limit of 40 mg.
• UK Myprotein The ZMA (1 capsule): 150 mg magnesium, 10 mg zinc, 3.5 mg vitamin B6. Comfortably within both systems' guidance.

Form matters too. Magnesium oxide is poorly absorbed: in one study only about 4% of it was absorbed, while magnesium aspartate, chloride and lactate did significantly better.⁷ In a 60-day trial at 300 mg a day, an amino-acid chelate and citrate were absorbed better than oxide, which made no difference compared with placebo.⁸ Both ZMAs above use some oxide; glycinate products use none.

Zinc is not harmless in excess: high doses reduce how much copper the body can absorb, which over time can lead to anaemia and weaker bones.¹⁴ If you choose a ZMA, pick one at around 10 mg of zinc and do not stack it with a high-zinc multivitamin.

Does magnesium raise testosterone?

There is no authorised health claim linking magnesium to testosterone, and the research does not justify buying magnesium for that reason. The authorised claim belongs to zinc: zinc contributes to the maintenance of normal testosterone levels in the blood.¹⁵ Here is what the magnesium studies men usually hear about actually show:

• A small 2011 trial gave sedentary men and tae kwon do athletes 10 mg of magnesium per kilogram of body weight for 4 weeks and reported higher free and total testosterone.⁴ That dose is about 800 mg a day for an 80 kg man, more than twice the US supplement limit, and the study was short and small.
• An observational study of 399 men aged 65 and over in Italy found that men with higher blood magnesium tended to have higher testosterone.⁵ An association in older men is not evidence that a supplement changes hormone levels.
• The ZMA trial in 42 trained men found no difference in anabolic hormones after 8 weeks.³

So if your diet is low in magnesium, correcting that is sensible in its own right. If testosterone is your concern, speak to your GP, who can test it properly.

Magnesium for men who train or sweat a lot

Men who train hard may need a little more magnesium, but supplements only help if you are short. A review from the US Department of Agriculture's nutrition centre found that strenuous exercise increases urinary and sweat losses that may raise magnesium needs by 10 to 20%, and that intakes under 260 mg a day in male athletes may lead to low magnesium status.² The same review found that supplementing physically active people who already have adequate magnesium has not been shown to improve performance, while those who are low do benefit.² A 2017 review reached a similar view: the need for magnesium rises with activity, and most of the performance findings come from people with low status or older adults.¹

In practice: if you train most days, sweat heavily or cut weight for a sport, check your food first, then use a moderate supplement. Magnesium contributes to normal muscle function and electrolyte balance, which is why it sits in our electrolyte drink as well as our capsules. If you use creatine too, our creatine guide for runners covers how the two fit into a routine.

"For men who train hard or sweat a lot, I look at the whole day, not just the supplement. Magnesium contributes to normal muscle function and electrolyte balance, but it works alongside enough food, fluid and sleep. I would rather see a steady daily dose with an evening meal than a large amount taken now and then."

Sarah Law, Naturopathic Nutritionist | Optimised Female

Which magnesium is best for men over 50?

A well-absorbed form such as glycinate at a moderate dose, checked against any medicines you take. Men over 50 have the same NHS figure of 300 mg (up to age 64) and a US RDA of 420 mg a day, and the NIH lists men aged 71 and over among the groups most likely to have low intakes.¹³

Two cautions matter more with age. First, magnesium can interact with some antibiotics, bisphosphonates, diuretics and acid-reducing medicines, so take advice and space doses as your pharmacist suggests. Second, the kidneys clear excess magnesium, so anyone with reduced kidney function should ask a GP before taking it. Our who should not take magnesium guide lists the common interactions.

Is magnesium glycinate good for men's sleep?

The evidence is encouraging but weak. A 2021 meta-analysis of three small trials in 151 older adults found people fell asleep about 17 minutes sooner on magnesium than placebo, but rated the evidence low to very low quality.¹⁰ One of those trials gave 500 mg a day to older adults for 8 weeks.¹¹ No sleep claim is authorised for magnesium. Many men still like glycinate as part of an evening routine; our which magnesium is best for sleep page goes through the trials.

Magnesium glycinate vs citrate vs oxide vs aspartate: which form?

Glycinate and citrate are the best-absorbed everyday forms; aspartate also absorbs well, and oxide absorbs poorly. Organic salts tend to do somewhat better than oxide, though a 2017 review of absorption studies found the differences between well-made forms are modest and that dose, food and the person matter as much as the salt.⁹

• Glycinate (bisglycinate): magnesium bound to glycine. Well absorbed, gentle on the gut, the usual choice for daily use. Glycinate and bisglycinate are the same compound; see glycinate vs bisglycinate.
• Citrate: well absorbed and mildly laxative. Good if regularity is a goal, less so if it is not.⁸
• Aspartate: absorbed better than oxide in a direct comparison; found in many ZMA products.⁷
• Oxide: the most magnesium per gram but about 4% absorbed in one study. Cheap, and common in budget tablets and blends.⁷
• Multi-form complexes: several salts in one capsule. Useful if you want variety in one product; see our magnesium complex comparison.

What to look for on a magnesium label

1. Elemental magnesium per serving. The figure that matters is the magnesium, not the compound. “2,750 mg magnesium glycinate” on our label gives 303 mg of magnesium; “1000 mg magnesium bisglycinate” on a Myprotein tablet gives 113 mg.
2. What a serving is. One tablet, two capsules, three capsules or four: compare price per daily dose, not per bottle.
3. The total against the limits. Add up every product with magnesium or zinc and compare with 350 mg (US) or 400 mg (NHS) for magnesium and 25 mg (NHS) or 40 mg (US) for zinc.
4. The forms named. “Magnesium (as aspartate, oxide)” tells you part of the dose is oxide.
5. Capsule and diet. Both Optimum Nutrition products use gelatin capsules; ours, Doctor's Best and both Myprotein products are vegan.
6. Testing. Look for third-party testing of the finished product, such as a lab report on magnesium content and heavy metals, or a sport certification if you are drug tested.

Our magnesium glycinate buyer's guide goes further into fillers, buffering and the brands that do not state their elemental figure.

How we make and test our magnesium

Magnesium Glycinate is made in the UK under GMP in a vegan hypromellose capsule, with one active ingredient: fully reacted magnesium bisglycinate. Our printed label states 2,750 mg of magnesium glycinate giving 303 mg of elemental magnesium per four capsules, 81% of the reference intake, 240 capsules and 60 servings a tub.

The Eurofins result (110,000 ± 22,000 mg/kg) is consistent with the 11% magnesium share stated on the label. The contaminant figures are far below the GB maximum levels for food supplements (3.0 mg/kg lead, 1.0 mg/kg cadmium, 0.10 mg/kg mercury).¹⁸ Our how we test magnesium glycinate page explains each test.

Magnesium Seven is the alternative for men who want several forms in one capsule: seven named forms (orotate, taurate, lactate, malate, glycinate, citrate and Sucrosomial magnesium) giving 329 mg of magnesium per four capsules, with vitamin B6 (2 mg, 143% NRV) and manganese (1 mg, 50% NRV). Vitamin B6 contributes to the regulation of hormonal activity and to normal psychological function.¹⁵ In a trial of 264 stressed adults with low blood magnesium, 300 mg of magnesium with vitamin B6 and 300 mg of magnesium alone gave similar results overall, with an advantage for the combination only in the most stressed subgroup.¹² It costs £38.95 or $44.11 for 30 servings, or £35.06 and $39.70 on a first Subscribe & Save order. Its label says it is not intended for pregnant or breastfeeding women.

When our magnesium is not the best choice

• If price per serving matters most. Doctor's Best tablets ($0.23 per 2 tablets) and the Myprotein bisglycinate tablet (£0.08 on offer) cost less per serving than our 63p or 72 cents, at lower doses per serving.
• If you want zinc in the same capsule. Ours contains no zinc; a UK-dose ZMA such as Myprotein The ZMA covers both.
• If you would rather drink it. Our glycinate is a capsule. Thorne's bisglycinate is a powder.
• If you are drug tested in sport. Thorne's powder carries NSF Certified for Sport; check what your governing body requires.
• If four capsules a day is too many. Two capsules give about 150 mg, or choose a product with a one-dose serving.

If you do try ours, every tub is covered by our 60-day money-back guarantee, and Subscribe & Save brings it to £34.16 or $38.68 a tub on the first order (57p or 64 cents a serving). Prefer cover across several forms? Magnesium Seven is the alternative.

Frequently asked questions

About the Reviewer: Sarah Law, Dip CNM

Sarah Law is a Certified Naturopathic Nutritionist and Functional Practitioner specialising in hormonal health, gut health, and evidence-based nutrition. She holds a Diploma in Naturopathic Nutrition from the College of Naturopathic Medicine (CNM, London) and is a Certified Functional Health Coach. Sarah combines naturopathic principles with modern functional nutrition science to help her clients make informed health decisions.

Learn more about Sarah.

About the Author: Ben Law

Ben Law is the founder of Love Life Supplements and host of the Optimised Health Show. He is a qualified Advanced Dietary Supplement Advisor and Primal Blueprint Certified Expert, and has spent 14 years building transparent, research-led formulations manufactured to GMP and BRC standards. He wrote this guide from the published magnesium and zinc research, NHS and NIH guidance, each brand's own product pages and supplement facts panels, and our own label and lab data.

Optimum Nutrition, Thorne, NSF Certified for Sport, Doctor's Best, Albion, Myprotein, The ZMA, ZMA and CoreChelate are trademarks of their respective owners and are not affiliated with Love Life Supplements. Learn more about Ben.