Magnesium and Testosterone

Magnesium is a mineral that exists naturally in many foods – nuts, cereals, pulses, rice, fish, vegetables, fruit, chicken and beef. Even water contains magnesium. Not just the fancy bottled stuff, tap water contains magnesium too.

You are more likely to suffer from low magnesium levels if;

  • You are a chronic alcoholic
  • You suffer from Type 2 diabetes
  • You have a gastrointestinal condition such as Crohn’s disease

But don’t assume that because so many foods contain magnesium that you are therefore likely to have sufficient levels. This 2005 Dietary Guidelines Advisory Committee Report found that half of the adult American population had a magnesium deficiency click here.

Supplementation can benefit you in the following ways

  1. Reduce hypertension through reduced blood pressure, thereby improving cardiovascular health. These effects have been found to be small and more effectively achieved by increasing magnesium levels (along with potassium and calcium) through eating more fruit and veg and less fat and dairy.
  2. Magnesium plays an important role in glucose metabolism. If your diet is high in magnesium then you have a lower risk of developing type 2 diabetes.
  3. We’ve already stated that around 50% of your body’s magnesium deposits can be found in your bones. Several studies have shown positive effects on bone density, so magnesium supplementation can mitigate against the chances of developing osteporosis.
  4. Can help to reduce migraines amongst sufferers.

Magnesium for Test Boosting

When we look at clinical studies and the actual evidence which is there to support claims that a substance will positively affect testosterone, we really look to see if there are studies done on humans.

Whilst animal/rodent studies have a degree of usefulness, the fact that a particular supplement increases the test levels in a rat is only really useful if you are a rat. Not only do we want human studies, if you are looking at test boosters for muscle gains then it’s even better if the study involves athletes.

Luckily, we have such studies. However as you find out it’s not simple to draw a conclusion from them… for some interesting reasons.

Study: Effects of a Novel Zinc-Magnesium Formulation on Hormones and Strength

Year: 1998
Brilla L., Conte V.
Institution: Exercise and Sports Science Laboratory, Western Washington University, Bellingham, USA

The original study, and the one you’ll often see quoted by the supplement manufacturers who produce ZMA. ZMA is a combination of vitamins and minerals comprising Zinc, Magnesium and Vitamin B6. This study was conducted by a Dr Lorrie Brilla and showed some spectacular gain of muscle strength and torque together with a spectacular 57.5% average increase in free testosterone levels. The study was on Varsity football players and played out over eight weeks.

Unfortunately the co-sponsor of the trial was SNAC, a subsidiary of BALCO – the company owned by the inventor of ZMA, Victor Conte. Who the sharp eyed will notice was also the co-lead researcher on the trial.

So hardly subjective and unbiased, there was a clear financial incentive for a result like this, and no subsequent clinical trial has come up with anything like these results.

Not that it mattered to our Vic of course. He went on to turn ZMA into an industry in itself, and it’s still sold today in vast amounts, although his company doesn’t own a patent on the blend (just a trademark). This is the reason you will often find derision amongst jaded supplement veterans when ZMA (and indeed the 3 constituents) are mentioned in relation to testosterone.

The perception of Magnesium and it’s importance to test has been tainted by this trial and the subsequent marketing hype of ZMA.

Study: Serum testosterone and urinary excretion of steroid hormone metabolites after administration of a high-dose zinc supplement

Year: 2007
Authors: Koehler K., Parr M., Geyer H., Mester J. and Schänzer W
Institution: Institute of Biochemistry, German Research Centre of Elite Sport, German Sport University Cologne, Cologne, Germany

It took them a while, but eventually the Germans got sick of reading about the wonders of ZMA and set out to disprove the claims by Brilla and Conte. Ok, it doesn’t actually say that anywhere in the abstract or full text, but you don’t have to be an expert at reading between the lines to see it.

You can tell just by reading the objective that this was the aim;

To investigate whether the administration of the zinc-containing nutritional supplement ZMA causes an increase of serum testosterone levels, which is an often claimed effect in advertising for such products

We are not going to get into clinical bias here, but suffice to say that when you have a group of people determined to disprove something, then consciously or subconsciously… they often tend to do just that.

As the opening introduction of the study itself notes, there is a strong and well established link between Zinc and testosterone;

The interrelations of the trace element zinc and the male sexual hormone testosterone (T) have been known for many years. Dietary zinc deficiency has been found to cause hypogonadism and growth retardation for the first time in the 1960s (Prasad et al., 1963). Reduced testosterone synthesis due to impaired action of superordinate hormones such as gonadotropin-releasing hormone, luteinizing hormone and follicle-stimulating hormone (McClain et al., 1984), and altered enzymatic conversion of testosterone (Om and Chung, 1996) have been identified as the main reasons for lower testosterone levels in zinc deficiency.

But the study concluded that ZMA contributed no statistical increase in serum total or free testosterone levels. Rather than focus solely on ZMA as a combination, it would have been better here would have been if they had actually done a trial on the separate elements.

It tells us little about magnesium supplementation effects on their own. It would also have given more weight to their study if they had used more than 14 subjects, a statistically small number of study particpants.

If the study had involved more participants, some of whom had low magensium levels, then we would know a lot more about magnesium and it’s effects on testosterone.

Study: Effects of magnesium supplementation on testosterone levels of athletes and sedentary subjects at rest and after exhaustion

Year: 2011
Authors: Cinar V., Polat Y., Baltaci A.K., Mogulkoc R.
Institution: Karaman High Medicine of Physical Education and Sports, Selcuk University, Karaman, Turkey

A study into the effects of magnesium supplementation in relation to exercise. 10mg magnesium per kilo of body weight in tae kwon do athletes.

The researchers discovered that free testosterone levels increased, as did total testosterone levels. It was shown that the supplementation had the greater benefit on those who were excercising.


The internet is a muddied mess in relation to magnesium and test. It’s hard to establish just how effective it is, whilst we wouldn’t recommend using a distinct magnesium supplement, it is worth having it there in a combined supplement. If you have low levels than it can impact your testosterone levels and then effectiveness of other testosterone boosting ingredients.

It’s certainly not the test boosting star it’s been touted as, but it’s not ineffective either.

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