All About ZMA
Rob Jones asks:
“Hey man, just wondering what your take on ZMA was for sleep quality – keep getting 8 hours and still feeling tired during the day. I know you’re having a bad time with sleep so thought you may have given it a whirl. Cheers mate”
To first provide some relevant background information, ZMA is a combination of zinc monomethionine aspartate, magnesium aspartate, and vitamin B6. Originally developed by Victor Conte, ZMA is intended to improve recovery following exercise, particularly during sleep.
ZMA’s Legal Status
As something of an aside, the patent status for ZMA is a bit odd. Specifically, a patent application for ZMA was filed in 2001, but not by Victor Conte; instead, the stipulated inventors were Luke Bucci, Alan Shugarman, Jeffrey Felliciano, Marta Draper Rodriguez, acting on the part of Weider Nutrition Group. Furthermore, the application extended beyond the traditional ZMA formula, to include multiple forms of zinc, multiple forms of magnesium, the addition of the amino acid L-theanine, as well as “a compound selected from the group consisting of kava kava, melatonin, GABA, valerian, skull cap, chamomile and green tea”, with wide dosage ranges, and even going so far as to specify route of administration (oral), timing (before or after dinner), and frequency (2-3x). Frankly, it’s unclear to me what conclusions to draw from this, and ultimately the patent application appears to have ended its life at the application stage, suggesting a failure on the part of the inventors to demonstrate a unique structure or function of their invention.
Despite ZMA’s non-patented status, it is trademarked, meaning that any compliant ZMA product is licensed by Victor Conte. Notably, this makes no indication of the effectiveness (or lack thereof) of ZMA, as it’s merely protective of the ZMA mark.
Does ZMA work?
To get to the question everyone wants answered: unfortunately, the research on ZMA is equivocal. First, a study performed by Victor Conte and a colleague, published in 2000, compared the effects of ZMA to placebo, finding ZMA to be strongly superior. The measured outcomes were extensive, including serum (blood) zinc and magnesium levels, free testosterone, and insulin-like growth factor-1 (IGF-1), along with performance outcomes. ZMA outperformed placebo in terms of every measured outcome, with these differences being both statistically significant and meaningful in practice.
Now, the supplement-loving side of me finds these results exciting, and I’m seriously considering purchasing a ZMA supplement, but caution is warranted when considering the scientific basis of ZMA’s purported effectiveness. Specifically, a follow-up study performed by a group wholly independent of ZMA’s trademark holders noted that while ZMA supplementation did succeed in elevating serum (blood) zinc concentrations (after all, ZMA does contain zinc!), it failed to outperform placebo in terms of, and I quote, “anabolic or catabolic hormone status, body composition, 1-RM bench press and leg press, upper or lower body muscular endurance, or cycling anaerobic capacity”. Although financial conflicts of interest do not necessarily strengthen or weaken the results of a particular study (after all, someone does need to fund research, and it’s understandably very often those who stand to financially benefit from it), in a context like this, in which the only two well-designed studies on the topic have literally antithetical results, I would suggest a tentative conclusion in favor of the independent study, although I wouldn’t go so far as to be confident in the claim that ZMA doesn’t work. With that said, when it comes to deciding whether or not to use a supplement, I think the evidence in favor of it, taken as a whole, needs to be compelling, and the single highly-favorable study on ZMA fails to meet that standard. As such, I wouldn’t feel comfortable recommending ZMA as a means of enhancing body composition or performance, and I wouldn’t think to use it myself for this purpose.
But what about sleep?
Remarkably, I’ve been able to find literally no research on the influence of ZMA supplementation on sleep. This is particularly striking given ZMA marketing appears to focus primarily on sleep and recovery from exercise, rather than direct body composition and performance outcomes – the outcomes which have actually been studied in well-designed research.
In short, the absence of research on this topic mandates a neutral position on the issue. However, once again viewing this question from a pragmatic perspective of the possibility of purchasing a ZMA product, the absence of any (let alone any compelling) scientific evidence for ZMA improving sleep naturally leads to the conclusion it’s not worth buying, unless one has sufficient discretionary income and simply wants to evaluate their individual response (a position I don’t find wholly unreasonable, but one which does need to account for the possibility of completely wasting money).
- ZMA is a trademarked combination of zinc, magnesium, and vitamin B6, purported to improve sleep and recovery.
- ZMA may increase testosterone and other anabolic hormones while concurrently improving exercise performance. However, these effects have only been shown in one study, a study which was carried out by one of the owners of the ZMA trademark. Independent research shows no improvements in anabolic or catabolic hormones, exercise performance, or body composition. Thus, extreme skepticism is warranted for these claims.
- There is an absence of research performed on the possible influence of ZMA on sleep. Thus, it is unwise to purchase ZMA for this purpose, unless one simply wishes to experiment with it.