ZMA
Research reviewed: up until 05/2023
ZMA (Zinc Monomethionine Aspartate) is a dietary supplement with 3 published peer-reviewed studies involving 43 participants, researched for Testosterone levels.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Testosterone levels
ModerateResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Testosterone levels
To evaluate the effects of zinc, magnesium aspartate, and vitamin B6 (ZMA) on the anabolic hormones and muscle function in varsity football players
Study Type
Randomised, double-blind trial
Purpose
To evaluate the effects of zinc, magnesium aspartate, and vitamin B6 (ZMA) on the anabolic hormones and muscle function in varsity football players
Dose
90 mg/day zinc monomethionine aspartate, 1350 mg/day magnesium aspartate, and 31.5 mg/day vitamin B-6 (3 x ZMA capsule with 30 mg zinc monomethionine aspartate, 450 mg magnesium aspartate, and 10.5 mg vitamin nightly between dinner and bedtime) or placebo
Participants
27 varsity football players
Duration
7 weeks
Results
The study found an association between ZMA (zinc, magnesium aspartate, and vitamin B6) intake during the athletes' training period and a significant increase in total testosterone, rising from 567.9 to 752.2 ng/mL, while a decrease was observed in the placebo group, dropping from 588.8 to 526.8 ng/mL. Similarly, free testosterone significantly increased with ZMA (132.1 to 176.3 pg/mL) compared to the reduction observed in the placebo group (141.0 to 126.5 pg/mL). Additionally, the researchers observed a significant increase in insulin-like growth factor I (IGF-1, a hormone that promotes bone and tissue growth) in the ZMA group. The researchers also observed increases in quadriceps torque by 10% and quadriceps power by 12.7%-15.2% in the group taking ZMA, which is significantly greater than the change of -0.8% to 2.4% in quadriceps torque and 8.6% to 10.8% change in quadriceps power in the placebo group.
To assess the effect of ZMA supplementation on sleep quality and submaximal weightlifting performance after partial sleep deprivation
Study Type
Double-blind, randomized, counterbalanced RCT
Purpose
To assess the effect of ZMA supplementation on sleep quality and submaximal weightlifting performance after partial sleep deprivation
Dose
ZMA supplementation
Participants
16 trained male athletes
Duration
3 experimental conditions with sleep deprivation
Results
ZMA supplementation had no significant effect on sleep quality or submaximal weightlifting performance after sleep deprivation
How They Measured It
Sleep monitoring, weightlifting performance metrics (average power, velocity, displacement)
To examine if acute ZMA intake following sleep deprivation benefits sleep and cognitive performance (Stroop test)
Study Type
Double-blind, randomized, counterbalanced RCT
Purpose
To examine if acute ZMA intake following sleep deprivation benefits sleep and cognitive performance (Stroop test)
Dose
ZMA supplementation
Participants
Males with adequate dietary magnesium and zinc
Duration
Acute study with sleep deprivation periods
Results
ZMA reduced sleep time and had no significant effect on morning Stroop interference performance after sleep deprivation
How They Measured It
Sleep architecture, Stroop Interference Task, cognitive performance
Frequently Asked Questions
Common questions about ZMA research
There are currently 3 peer-reviewed studies on ZMA (Zinc Monomethionine Aspartate), involving 43 total participants. Research covers Testosterone levels. The overall evidence strength is rated as Moderate.
The evidence is currently rated as "Moderate Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (3 human studies), and reported outcomes.
ZMA has been researched for: Testosterone levels. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 3 out of 3 studies are human trials. Human trials carry more weight in our evidence scoring system.
