Zinc, Magnesium and B6 (ZMA)

Description

ZMA is the old nightly combination of zinc, magnesium and vitamin B6, and on this panel each of the three is listed in milligrams rather than hidden inside a blend total. The abbreviation has been on shelves for twenty five years. What has changed is that a ZMA label here states the elemental amounts and the chemical forms, which the original category mostly did not.

On the panel

What the original ZMA formula actually was

The patented combination was 30 mg of zinc as monomethionine and aspartate, 450 mg of magnesium as aspartate, and 10.5 mg of vitamin B6. Those are elemental figures for the two minerals, which is where the capsule count comes from.

Magnesium aspartate is only around 7 to 8 percent elemental magnesium by mass, so 450 mg of the element needs several grams of the salt. Any ZMA product promising that figure in two small capsules is either using a denser compound or quoting the compound weight. Both numbers belong on a label, and both are on this one.

What the research found, including the unflattering part

The trial that launched this category was small, industry supported, and measured serum testosterone and strength in trained athletes over eight weeks. A later independent trial in resistance trained men used a comparable protocol and measured no difference in testosterone or in performance against placebo.

That is a description of the published literature on ZMA, including the study that did not support it, and it is not a claim about this bottle in either direction. We print both results because a buyer reading only the first would be misled, and because the ingredients are worth having on their own terms.

Why zinc and magnesium are worth printing separately

Because the elemental percentages differ so widely between forms. Zinc gluconate is about 14 percent elemental, picolinate nearer 20, oxide around 80. Magnesium oxide is roughly 60 percent, citrate about 11 and glycinate closer to 14.

A combined blend figure makes all of that invisible, which is exactly what a proprietary total is permitted to do. The legal background is in what a proprietary blend is legally allowed to leave out, and the elemental arithmetic for every mineral is on the minerals page.

The calcium note

Calcium competes with both zinc and magnesium for absorption, which is why the panel says to take this away from a calcium supplement. In practice that usually means calcium in the morning and this at night, a separation of several hours rather than minutes.

The B6 ceiling

Vitamin B6 has a tolerable upper intake level of 100 mg a day for adults, set because sustained high intakes are associated with sensory neuropathy in the published literature. The amount in a ZMA serving is a small fraction of that, and it is printed so it can be added to whatever else you take.

Why it is a night time product

Convention, mostly, and the fact that zinc is better tolerated with food and magnesium is often preferred in the evening. There is no mechanism in the literature that requires a ZMA serving to be taken at a particular hour, and we are not going to invent one.

Testing

Every lot is assayed for all three actives by a laboratory with no ownership link to this company, with heavy metals and microbials screened alongside. Under strength lots are withdrawn and the failing certificate stays public. Reference intakes and food sources for magnesium are on the NIH magnesium fact sheet, the rest of this shelf is on the men’s page, and your lot certificate is linked above. Zinc, magnesium and B6 in a zma serving are each listed at their own weight on the panel, because the three letter name tells you the ingredients and none of the amounts.