Does ZMA Actually Work?
For my fifth article on dietary supplements used by athletes, I am going to review the supplement ZMA or Zinc Magnesium Aspartate. One of the most commonly asked questions about this supplement that I’m asked is, “Does ZMA work?
Ingredients in ZMA
Common preparations of ZMA include the ingredients: Zinc, Magnesium, and Vitamin B6. Some ZMA formulations add various other ingredients to make their product unique.
Who invented the ZMA formulation?
To provide some historical context, ZMA was developed by Victor Conte (founder of Balco). Balco or the Bay Area Laboratory Co-operative, who became infamous for its implication in a steroid scandal involving numerous Olympic athletes who have subsequently lost their medals including Marion Jones. In particular, the steroid tetrahydrogestrinone (THG), which was often referred to as “the clear,” was an undetectable performance enhancing steroid used by these athletes.
Okay, now does ZMA actually work?
Though several companies market various ZMA type products, the current evidence that these products have any effect on strength, hormone status, or body composition is currently lacking [1]. Researchers at Baylor University in Texas published the results of an 8-week study made the follow conclusions:
“However, no significant differences were observed between groups in anabolic or catabolic hormone status, body composition, 1-RM bench press and leg press, upper or lower body muscular endurance, or cycling anaerobic capacity. Results indicate that ZMA supplementation during training does not appear to enhance training adaptations in resistance trained populations” [1].
In summary, the study in 2004 by Wilborn et al found that ZMA did not work at all for enhancing anabolic hormone status, increasing muscle mass, improving strenght, or enhancing endurance or anaerobic capacity. The participants in this study included 42 resistance trained males who took the supplement prior to resistance training for a total of 8 weeks.
What was in the ZMA supplement for this study?
The ZMA supplement used in this study was provided by Cytodyne Technologies called Zmass PM™. It contained the follow ingredients:
- 11 mg of Vitamin B-6 (pyridoxine hcl)
- 30 mg of zinc (as monomethionine and aspartate)
- 706 mg of a proprietary blend of mucuna pruriens (seeds) standardized for 50 mg of L-Dopa (purported as a muscle relaxant) and Polypodium Vulare/Suma root (herb) standardized for 30 mg of 20-hydroxyecdysone (a plant sterol purported to reduce catabolism).
Does ZMA increase testosterone levels?
A more recent study published by German researchers in the European Journal of Clinical Nutrition found that supplementation with ZMA did not enhance either free or total serum testosterone levels [2]. This particular study included 14 healthy men who engaged in regular exercise.
Bottom line: Don’t waste your money!
From the current studies available regarding the lack of effectiveness at ZMA supplementation for improving body composition, strength, endurance, or improving testosterone levels, you probably shouldn’t waste your money on this supplement.
References:
- Wilborn CD, Kerksick CM, Campbell BI, Taylor LW, Marcello BM, Rasmussen CJ, Greenwood MC, Almada A, Kreider RB. Effects of Zinc Magnesium Aspartate (ZMA) Supplementation on Training Adaptations and Markers of Anabolism and Catabolism. J Int Soc Sports Nutr. 2004 Dec 31;1(2):12-20
- Koehler K, Parr MK, Geyer H, Mester J, Schänzer W. Serum testosterone and urinary excretion of steroid hormone metabolites after administration of a high-dose zinc supplement. Eur J Clin Nutr. 2009 Jan;63(1):65-70. Epub 2007 Sep 19.
Jeffrey
April 25, 2013 at 12:51 pm
Regarding ZMA, when I was in medical school I took my graduate level electives in nutrition. I learned the most important thing, how to read scientific studies. My first real ahhh-haaa experience happened after the news blew up (late 90′s) about a new study showing that 30 mg Zinc supplementation significantly increased free testosterone in a group of men. It was a double-blind, placebo controlled, cross-over study, the Absolute gold standard of scientific studies. So that was that, right? The methodology of the study was impeccable. Zinc increases testosterone, case closed (?).
Zinc started flying off shelves (I know because at the time I worked PT in a health food store). I took it and recommended it. Then I dug deeper….and managed to find a caveat that was buried within the fine details of the study. ALL of the men in the study were zinc deficient, and deficient in testosterone upon starting the study. Since zinc is absolutely essential for testosterone production, it was no surprise the researchers found a group where the two variable were correlated, i.e. both low serum testosterone and zinc.
So all that happened is when these men took zinc, they Corrected A Deficiency, and of course their levels of testosterone raised to that of a normal, healthy man, nothing more. Their levels rose in the 30-37% range, in each man exactly the amount to bring them WNL, within normal limits.
NO research EVER has shown that giving zinc to a man not deficient in zinc and having WNL testosterone, that it raises testosterone. Because it absolutely will not. And that is why it pays to either learn all the science behind this stuff, or count on someone who not only has the knowledge but has your best interest in mind. Always think about someone’s motivation in recommending a product.
Sb
March 16, 2013 at 4:20 pm
Hi
I take zma almost religiously….what affect it has on muscle mass I can’t say, but my sleep is awesome out like a light every night and the benefits of that alone are worth it, I pay about $30 for 4 months supply from a bulk supplement outlet….25c a day is never going to break me.
Mark
October 10, 2011 at 3:37 pm
I did some research on this supplement and found pretty much the same findings as you. There aren’t many studies out there, but the ones that are out there are from SNAC Systems (who say it does increase testosterone levels) and then the more credible sources such as those published on PubMed (which do not concur with SNAC Systems).
curiozitati
January 25, 2011 at 11:54 am
i think it works… i used to take some, but the truth is i didn’t take just ZMA, i also took some l-carnitine and others, so i’m not sure exactly if it works… but for me it worked, whatever that was… whether was the l-carnitine, whether the cromium.. i don’t know
Jake R
December 7, 2010 at 6:22 pm
My best friend’s brother is bulking up right now and he loves this stuff and swears by it.
However he also uses protein powder and creatine and I think they’re doing the bulk of the work as far as his supplements are concerned.
SGK
November 18, 2010 at 12:43 pm
This ZMass in the first study isn’t the same a Conte’s ZMA (30mg of Zinc and 450mg of Magnesium and 10.5mg B6)
In my experience taking ZMA as directed has increased my libido, better sleep and more consistent and persistent “morning wood”. These all suggest to me that my T is elevated.
Jarret Morrow, M.D.
November 19, 2010 at 10:44 am
Hi SGK, the problem is that there haven’t been many studies on ZMA. The only one that showed promising results was Conte’s which he only presented an abstract of at meeting from what I understand. Also, Conte doesn’t appear to be a credible source of information. Thanks for sharing your experiences with ZMA–many people seem to offer anecdotes of improved sleep.
Simple Human
October 23, 2012 at 10:21 am
In the deepest sleep cycles is when we release about 70% of our growth hormones, so if your taking Zinc (which acts to improve quality of sleep) then you increase your chances of getting to that 5th sleep cycle which will release huge amounts of growth hormone which may account for, “morning wood.” As for the increase in T, I believe its from better sleep as well!
Jarret Morrow, M.D.
May 29, 2010 at 7:03 pm
Hey Chris, thanks for your feedback on ZMA and tribulus terrestris.
Personally, I wouldn’t recommend spending your money on either. There really isn’t convincing evidence that either supplement works.
Here’s a fairly good summary of supplements for athletes/body building that have been reviewed on basis of evidence: http://www.jarretmorrow.com/win-olympic-medals-earn-endorsement-contracts/
chris
May 29, 2010 at 7:28 am
Used ZMA for pry like 3 days now, stacked with Tribulus terrestris, slightly seem to be noticing my abdominal muscle region showing better already. I’m still not 100% positive if it is working. It could be the effects of my whey protein or nitric oxide products I supplement with. But I wouldn’t expect drastic results too soon like I noticed slightly . its probably a long term effect.
Jack
January 5, 2010 at 8:28 pm
So far I’m not convinced ZMA is worth the money. I think I’d be better off spending more on creatine and protein. These things I know work.
Jarret Morrow, M.D.
April 11, 2010 at 3:12 pm
Jack, creatine and protein are certainly the top-2 researched supplements for increasing muscle mass.
Tradd
September 16, 2009 at 10:45 am
I was just searching for ZMA and diabetes when i came across this article. I am a diabetic bodybuilder and have tried ZMA in the past and just started on it again recently. Having my blood sugars under complete control, mainly because of lifting, there are very few outside things that will make my sugars spike to very high levels. If I get very sick (flu, etc.) they will stay high or if my hormones swing to high levels due to stress, they’ll peak as well. If I’m prescribed Prednesone, my blood sugar will hit about 400 and stay there until the drug wears off. When taking ZMA before bed, I wake up feeling very rested, but my blood sugar is in the 350 range (about 3 times normal). This spike is short-lived and doesn’t linger all day like a steroid, but happens when I take the full dose (4 capsules for the Dymatize product). This leads me to believe that ZMA is causing a testosterone spike during the night. I have since remedied that by taking 3/4 to 1/2 doses, enjoying the restful sleep and extremely vivid dreams, and not having to worry about the large spikes in blood sugar readings. I also feel like I have more power and endurance at the gym when taking ZMA.
I apologize for the long post, but could this symptom help explain what ZMA is doing?
Jarret Morrow
August 9, 2009 at 6:14 pm
Hi Tex, I myself am not familiar with SNAC systems in terms of their brand. There have been cases of OTHER manufacturers putting drugs in their products. If you’re concerned about this, you may want to consider switching brands–at least to see if other ZMA products have the same effect for you.
Jarret Morrow
July 31, 2009 at 5:18 pm
Thank you for the feedback.
TEX
August 9, 2009 at 5:43 pm
I wonder if the ZMA produced by SNAC systems is perhaps spiked with another chemical? I have used ZMA and definitely noticed increased libido, better sleep and increased gains form the gym. I know my body well and I can tell you that ZMA does promote heightened testosterone levels at least. This is good if that is your objective in using the supplement, however I can’t help but to wonder if ZMA users are not unknowingly consuming something more than what is listed on the back of the bottle.
Scott Welch
November 9, 2008 at 5:12 am
Great feedback. I also used ZMA during that era and experienced noticeable improvements in sleep. I read some research that Magnesium enhances Melatonin production and thought maybe that was a contributor. I have interviewed dozens of athletes that swear it makes them sleep better also.
Jarret Morrow
November 7, 2008 at 6:47 pm
Scott, thank you again for your comment. Clearly, my blog is probably one of the least personally revealing blogs around–however, I am going to diverge from that for a moment. I personally actually tried ZMA several years ago–somewhere between the Victor Conte abstract being published and the Balco scandal.
Subjectively, I noticed two things–one, for whatever reason, after taking it before going to bed, I always seemed to wake up before my alarm clock rang–say about 6 am. The only other effect that I personally observed was that after taking it for nearly a month, my hair started to fall out in clumps. It got to the point where I had a bald spot on the top of my head which is when I stopped taking the product. Thankfully, my hair has subsequently filled back in.
Excess zinc can cause hair loss which might explain what I experienced from the ZMA product.
Cam
January 29, 2012 at 6:29 am
Is the evidence of hair loss not evidence of increased Testosterone????Doesn’t testosterone, as DHT, cause hair loss . . .so a sudden increase in hair loss at the same time as taking the supplement, which stopped when the supplement stopped would suggest increased testosterone
Scott Welch
November 6, 2008 at 2:15 am
I agree completely with Simon that the Zinc, and Magnesium in ZMA are both highly bioavailable.
However, if you’re not deficient in either mineral, it makes even less sense to supplement with such a highly bioavailable mineral supplement. Zinc and Magnesium are both fat soluble and thus taking excess may be toxic.
Jarret Morrow
September 14, 2008 at 7:48 pm
Simon, thank you for your comments regarding ZMA. Let me ask you this… I am guessing that consumers have spent millions of dollars on ZMA. Now, do you think they’re purchasing ZMA because of widespread fear of Zinc and Magnesium deficiency or because of Victor Conte’s initial abstract that suggested it naturally increased IGF-1 and testosterone levels?
simon
September 14, 2008 at 2:14 am
ZMA may not increase your testosterone levels. But the Zinc, and Magnesium in it are both highly bioavailable. At least compared to the standard Mg oxides found in normal OTC mineral supplements. With large portions of the weight lifting population being zn and mg deficient its a good supplement. Unfortunately it is often consumed along with protein powders that contain a lot of Calcium. Calcium competes for uptake with both zinc and magnesium. Which can further skew results.
I think that the study you cite looks at response areas that are too “big” or “broad” to be easily effected by a simple nutrient deficiency. If you peruse the literature for the effects of Zn/Mg deficiency you can see the possible benefits of supplementation with ZMA.