# Does ZMA work?

Source: https://www.healthnews24.co.za/answers/zma-supplement-does-it-work/
Publisher: Healthnews24 (South Africa's supplement answer desk)
Updated: 2026-10-27

> No good evidence shows ZMA (zinc, magnesium aspartate and vitamin B6) raises testosterone or builds muscle in healthy trained men. In an 8-week trial of 42 resistance-trained men, ZMA changed neither testosterone nor strength compared with placebo. It may help only if you are low in zinc or magnesium. In South Africa, test or fix diet before buying.

Key facts:
- In an 8-week trial of 42 resistance-trained men (Wilborn 2004), ZMA did not change total or free testosterone versus placebo.
- Bench press gains were +5.6 kg with ZMA and +3.6 kg with placebo (p = 0.24); leg press +25.4 kg versus +24.6 kg (p = 0.92).
- The trial dose of 30 mg zinc and 450 mg magnesium exceeds EFSA's supplemental upper limits of 25 mg and 250 mg.
- As of October 2026, Dis-Chem Gold Zinc Complex costs R2.67 a day and Dis-Chem Gold Magnesium Chelate about R3.33 per tablet.

## What is ZMA?

ZMA is a night-time supplement combining zinc (often as monomethionine and aspartate), magnesium aspartate and vitamin B6. It is marketed to bodybuilders and athletes as a way to raise testosterone, improve sleep and speed recovery.

## What does the research show?

A well-known controlled trial is Wilborn and colleagues (Journal of the International Society of Sports Nutrition, 2004): an 8-week, double-blind, placebo-controlled trial in 42 resistance-trained men. The daily dose was four capsules before bed supplying 30 mg zinc, 450 mg magnesium and 11 mg vitamin B6.

| Outcome | ZMA | Placebo | Result |
|---|---|---|---|
| Total and free testosterone | no significant difference | no significant difference | not significant |
| Bench press 1RM gain | +5.6 kg | +3.6 kg | p = 0.24, not significant |
| Leg press 1RM gain | +25.4 kg | +24.6 kg | p = 0.92, not significant |

The authors concluded ZMA did not appear to enhance training adaptations in this group. Evidence level: weak for healthy, trained, well-fed men. Zinc and magnesium help correct a deficiency, which is a different claim from boosting hormones.

## When might ZMA-type ingredients help?

Only if you are short. Athletes with heavy sweat losses and restricted diets, vegans, and people with diagnosed low zinc or magnesium may benefit from correcting the shortfall. The AIS lists zinc as a Group A medical supplement for diagnosed deficiency and magnesium in Group C. See [do you need a zinc supplement?](/answers/do-i-need-zinc-supplement-south-africa/) and [how much magnesium per day](/answers/how-much-magnesium-per-day/).

## Are the doses safe?

The trial dose is high relative to the limits for supplements:

| Nutrient | Trial dose per day | Upper limit for supplements |
|---|---|---|
| Zinc | 30 mg | 25 mg (EFSA) or 40 mg (NIH) |
| Magnesium | 450 mg | 250 mg (EFSA) or 350 mg (NIH) |

Zinc at 50 mg or more over weeks can block copper absorption, and high magnesium mainly causes diarrhoea and is risky in kidney disease. Using ZMA together with a multivitamin or other zinc and magnesium products can push totals higher ([can you take too many vitamins?](/answers/can-you-take-too-many-vitamins/)).

## Is ZMA sold in South Africa, and what is cheaper?

We did not find a ZMA product in our October 2026 price sample, so we do not quote a price. If a doctor finds you low in either mineral, separate single-nutrient products let you choose each dose. As of October 2026, Dis-Chem Gold Zinc Complex costs R2.67 a day at two tablets (about 16.6 mg zinc, elemental not confirmed), and Dis-Chem Gold Magnesium Chelate costs about R3.33 per tablet (99 mg elemental magnesium), both at Dis-Chem Living Fit.

## What about anti-doping and "testosterone booster" products?

SAIDS flags muscle-building and "testosterone booster" products as the highest-risk category for contamination, and the AIS Group D list includes herbal testosterone boosters such as Tribulus and maca. Many boosters are blends rather than plain mineral products, so read the label. Under-18s should avoid them entirely, and nobody should treat low testosterone symptoms with supplements without seeing a doctor. See [testosterone-booster and banned-ingredient warnings](/answers/what-supplements-are-banned-in-south-africa/).

## Products mentioned

| Product | Size | Price (source, date) | Servings | R per serving | Sweeteners |
|---|---|---|---|---|---|
| Dis-Chem Gold Zinc Complex value pack 120 tablets | 120 tablets | R160 (Dis-Chem Living Fit, 2026-10) | 60 | R2.67 | not stated |
| Dis-Chem Gold Magnesium Chelate 90 coated tablets | 90 tablets | R300 (Dis-Chem Living Fit, 2026-10) | 60 | R5.00 | not stated |

## Sources

- [Wilborn et al. 2004, Effects of zinc magnesium aspartate (ZMA) supplementation on training adaptations and markers of anabolism and catabolism (JISSN 1:12)](https://pmc.ncbi.nlm.nih.gov/articles/PMC2129161)
- [NIH Office of Dietary Supplements: Zinc, health professional fact sheet](https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/)
- [EFSA: Overview of tolerable upper intake levels (summary report, 2024)](https://www.efsa.europa.eu/sites/default/files/2024-05/ul-summary-report.pdf)
- [Australian Institute of Sport Supplement Framework, Group D](https://www.ausport.gov.au/ais/nutrition/supplements/group_d)
- [SAIDS (South African Institute for Drug-Free Sport) FAQ: supplements, strict liability, medication check](https://drugfreesport.org.za/faq/)