Does Magnesium Increase Testosterone?

1. Does magnesium raise testosterone?

One trial says it can. That trial is small, short, and used a dose you would not take by accident.

The study most often cited is a 2011 paper in Biological Trace Element Research. It ran for four weeks in young men.

There were three groups. Sedentary men taking magnesium. Tae kwon do athletes training 90 to 120 minutes a day, taking magnesium. And athletes training the same hours, taking none.

The authors concluded that magnesium raised free and total testosterone in both supplemented groups, and that the rise was larger in the men who trained.

Now the small print. The dose was 10 mg per kilogram of body weight per day. For a 75 kg man that is 750 mg a day, well above the level the NHS treats as comfortable. Four weeks is short. The third group took no capsule at all, so nobody was blinded. And the study did not establish whether these men were short of magnesium to begin with.

2. What if you already get enough?

That is the question the evidence does not answer. Which is worth knowing before you buy anything.

The other well-known finding is observational. A 2011 study in the International Journal of Andrology looked at 399 men aged 65 and over, average age 74.

Men with higher blood magnesium had higher total testosterone. The link held after adjusting for age, body weight, inflammation, SHBG and insulin.

That is an association, not a lever. Men with better magnesium levels tend to eat better and move more. Either of those could be doing the work.

What is missing is the study that would settle it. A large, placebo-controlled trial in men whose magnesium is already normal. It has not been done.

The regulator has noticed. The GB nutrition and health claims register permits one relevant wording, that magnesium contributes to the reduction of tiredness and fatigue. There is no authorised claim linking magnesium to testosterone. Our review of testosterone booster supplements finds the same gap across most ingredients.

3. How much magnesium do you need?

The NHS puts it at 300 mg a day for men aged 19 to 64, and 270 mg a day for women. Spinach, nuts and wholemeal bread are the everyday sources.

“You should be able to get all the magnesium you need by eating a varied and balanced diet.”

— NHS, Vitamins and minerals

There is a ceiling too. The NHS says 400 mg a day or less from supplements is unlikely to cause harm, and that going above that for a short period can cause diarrhoea.

Read that next to the trial dose. A 75 kg man in that study was taking roughly double the NHS comfort line, under supervision, for four weeks.

For reference, the magnesium capsule in the Helvy Plan stack provides 150 mg of elemental magnesium, taken once or twice a day. That sits inside the ceiling at either dose. Form matters less than most labels suggest, which our guide to which magnesium to take covers in full.

4. Are you likely to be short of it?

More likely than with most minerals, and more likely if you are young. A 2018 analysis of the National Diet and Nutrition Survey looked at 3,238 British adults aged 20 to 59.

It found 15% of men and 12% of women had magnesium intakes below the lower reference nutrient intake. Among adults in their twenties that rose to about 1 in 5.

None of that proves a shortfall in you. It only says the odds are not trivial. Low intake also shows up as cramps and poor sleep long before anyone thinks about hormones, which our guide to the signs of low magnesium walks through.

5. Which markers show where you stand?

Two numbers answer this, and you can have both. Your magnesium, and your actual testosterone.

Magnesium sits in our General Energy & Wellness panel (£149) and our Vitamins & Minerals panel (£159). The second one reads it alongside a full iron workup, vitamin B12, folate and vitamin D.

Serum magnesium has a known limit. Most of your magnesium sits in bone and inside cells, so a blood level can look normal while intake is poor. Our guide to the magnesium blood test explains what it can and cannot show.

For the hormone side, our Complete Male Hormones panel (£119) measures total testosterone, free testosterone, SHBG, LH, FSH, prolactin, DHEA-S, free androgen index and albumin. Nine markers, from one home finger-prick sample.

Timing matters here. Testosterone peaks in the morning and drifts down through the day, so an afternoon sample can read low for no real reason. Our guide to the best time to test testosterone covers the window, and testosterone levels by age shows what normal looks like at yours.

A blood test measures these markers. It does not diagnose anything, and a result that worries you belongs with your GP. For the wider picture, start at the men’s hormones hub.

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