NOW Sports ZMA Review
#6 of 6 · The ZMA option✓ Label verified · Supplement Facts read Oct 13, 2026Real retailer photo, cut out. Label unedited.
Consider it. A fair zinc and magnesium capsule, not a testosterone booster. You get the 30 mg zinc dose from the studies plus 450 mg of magnesium and 15 mg of B-6.
$19.59 · 90 capsules (Amazon US, Oct 13, 2026)$0.65 per 3-capsule serving (30 mg zinc)
Why It Scores 7.4 — And The Label Line Behind Each Number
Form bioavailability
30% of scoreThe panel lists zinc from zinc mono-L-methionine, zinc aspartate and zinc oxide. The share of each is not printed. Mono-L-methionine and aspartate are well-absorbed forms; oxide is the weakest common form. A mixed form with an unknown split scores below the single chelates.
- Active form
- Zinc from zinc mono-L-methionine, zinc aspartate and zinc oxide
- Other ingredients
- Hypromellose (cellulose capsule), stearic acid (vegetable source), silicon dioxide
Dose accuracy + cofactor compatibility
25% of score30 mg of zinc per three capsules matches Prasad 1996. The serving also has 450 mg of magnesium, from aspartate and oxide, and 15 mg of vitamin B-6 (882% of the Daily Value). Women take two capsules: 20 mg zinc, 300 mg magnesium, 10 mg B-6. The label says to take it on an empty stomach, which is when zinc most often causes nausea.
- Per serving (men)
- 3 capsules: 30 mg zinc, 450 mg magnesium, 15 mg vitamin B-6
- Per serving (women)
- 2 capsules: 20 mg zinc, 300 mg magnesium, 10 mg vitamin B-6
Third-party testing
20% of scoreThe Informed Sport mark is printed on the label, and NOW states that every batch is screened and tested for banned substances. The label also carries the GMP Quality Assured mark. We could not query the Informed Sport database ourselves.
- Label directions
- 3 capsules daily (men) or 2 (women), on an empty stomach, 30 - 60 minutes before bedtime; avoid dairy and calcium
- Testing
- Informed Sport mark and GMP Quality Assured mark on the label
Cost per active mg
15% of score$19.59 for 90 capsules on Oct 13, 2026: $0.65 per three-capsule serving. As a source of zinc alone that is expensive; the price also covers 450 mg of magnesium.
- Bottle
- 90 veg capsules: 30 servings for men, 45 for women
- Price
- $19.59 for 90 capsules (Amazon US, Oct 13, 2026)
- Cost per serving
- $0.65 (men, 3 capsules)
Real-world response evidence
10% of scoreWilborn 2004: eight weeks of ZMA in 42 resistance-trained men, no effect on testosterone, strength or body composition. Koehler 2009: 14 active men on a zinc-sufficient diet, zinc levels went up, testosterone did not. Zinc raises testosterone when a man is low in zinc (Prasad 1996), not otherwise.
Label verified. Every figure read from the Supplement Facts photo, Oct 13, 2026.
Marketing Claims Vs. Reality
Muscle strength.
Wilborn 2004 gave ZMA or placebo to 42 resistance-trained men for eight weeks and found no difference in strength, body composition or anabolic hormones.
Enhanced absorption.
Zinc mono-L-methionine and aspartate are well-absorbed forms. The formula also contains zinc oxide and magnesium oxide, which are not, and the panel does not say how much of each form is used.
Tested for banned substances.
The Informed Sport mark is printed on the label. We could not open the Informed Sport database to confirm the batch listing ourselves.
Sports recovery.
Hard training raises zinc and magnesium losses, and replacing them is reasonable. No controlled study shows faster recovery from ZMA in people with normal mineral status.
What Our Test Actually Found
The testosterone claim does not hold up
ZMA became known through a study in college football players that was co-authored by the developer of the product. Two later studies did not repeat it. In Wilborn 2004, eight weeks of ZMA changed neither testosterone nor strength in 42 trained men. In Koehler 2009, ZMA raised zinc in blood and urine in 14 active men who already ate enough zinc, and left testosterone where it was.
What zinc can do for testosterone
Prasad 1996 is the study the whole category rests on: 30 mg of zinc a day raised testosterone in older men who were marginally zinc deficient. If your zinc is low, any well-absorbed 30 mg product does this, at a lower price. If your zinc is normal, extra zinc does not add testosterone.
Three zinc forms, shares unknown
The panel names zinc mono-L-methionine, zinc aspartate and zinc oxide as sources of the 30 mg. Magnesium comes from aspartate and oxide. Oxide forms are cheap and poorly absorbed, and the label does not say how much of each is inside.
Empty stomach, before bed
The label directs three capsules on an empty stomach 30 to 60 minutes before bedtime, away from dairy and calcium. That helps absorption and is also how zinc most often causes nausea. If it does, take it with a small meal.
Full analysis: all pros & cons (10), buy if / skip if
- 30 mg of zinc per serving, the study dose
- 450 mg of magnesium in the same serving
- Informed Sport mark on the label
- Separate serving for women printed on the panel
- Vegan capsule, three other ingredients
- No rise in testosterone in two controlled studies
- Zinc and magnesium partly from oxide, shares not printed
- Three capsules per serving
- $0.65 per serving, costly as a zinc source
- Label directs use on an empty stomach
- You train hard and want zinc and magnesium in one product
- You want a banned-substance tested product: the label carries the Informed Sport mark
- You prefer a bedtime mineral routine
- You are buying it to raise testosterone: the controlled studies found no effect
- You want a single, well-absorbed zinc form
- Zinc on an empty stomach upsets you: the label says to take it that way
You get the 30 mg zinc dose from the studies plus 450 mg of magnesium and 15 mg of B-6. The zinc comes from three sources, one of them zinc oxide, and the amounts of each are not given. In the two independent studies of ZMA, testosterone did not move. Buy it for the minerals, and only if you want both in one product.
ZMA is the zinc product most men think of when they hear zinc and testosterone. NOW Sports ZMA is the standard version: three capsules give 30 mg of zinc, 450 mg of magnesium and 15 mg of vitamin B-6, taken before bed. The bottle carries the Informed Sport mark. The honest part is the evidence. Wilborn 2004 and Koehler 2009 tested ZMA in trained and active men and found no change in testosterone. It is a decent zinc and magnesium product for people who train hard and sweat a lot, and a weak testosterone product.
On this list so you know what it does and does not do
NOW Sports ZMA ranks last here on purpose. It is the product men ask about, it delivers the 30 mg zinc dose, and the label carries a banned-substance testing mark. But the two independent studies of ZMA found no effect on testosterone, and the mixed zinc forms keep it below the single chelates. If you want zinc for testosterone, start with a 30 mg picolinate or glycinate. If you want zinc and magnesium together before bed, this does that.
If This Doesn’t Fit — Try These
01Thorne Zinc Picolinate
The default first-time pick for the testosterone endpoint.
03NOW Zinc Glycinate
If you've confirmed you're deficient and just want the cheapest legitimate way to run the Prasad protocol, NOW Foods is the answer.
04Garden of Life Raw Zinc
If you're a raw-food / whole-food buyer who refuses isolated chelates on principle, Garden of Life is the cleanest version of that philosophy at the right 30 mg dose.
Quick Answers
Does ZMA raise testosterone?
Not in the controlled studies. Wilborn 2004 (42 trained men, eight weeks) and Koehler 2009 (14 active men) found no change in testosterone. Zinc raises testosterone when a man is low in zinc (Prasad 1996).
How much zinc is in NOW Sports ZMA?
30 mg per three-capsule serving for men and 20 mg per two-capsule serving for women, printed on the Supplement Facts panel, together with magnesium and vitamin B-6.
Why take ZMA on an empty stomach?
The label says so, and to avoid dairy and calcium, because both lower zinc absorption. The downside is nausea, which zinc causes more often without food.
Is NOW Sports ZMA tested for banned substances?
The label carries the Informed Sport mark and NOW states that every batch is screened. We could not check the Informed Sport database ourselves.
Sources & Further Reading
4 peer-reviewed sources, each linked to PubMed
- [1] Wilborn 2004 PMID 18500945 — Effects of Zinc Magnesium Aspartate (ZMA) Supplementation on Training Adaptations and Markers of Anabolism and Catabolism. 42 resistance-trained men took ZMA or placebo for eight weeks of training. No significant differences in anabolic or catabolic hormones, body composition, bench press or leg press strength.
- [2] Koehler 2009 PMID 17882141 — Serum testosterone and urinary excretion of steroid hormone metabolites after administration of a high-dose zinc supplement. 14 healthy, regularly exercising men with a zinc-sufficient diet took ZMA. Serum and urinary zinc rose; serum total and free testosterone did not change.
- [3] Prasad 1996 PMID 8875519 — Zinc status and serum testosterone levels of healthy adults. Zinc at 30 mg a day for six months raised serum testosterone in marginally zinc-deficient older men. The effect depends on being low in zinc to begin with.
- [4] Maares & Haase 2020 PMID 32183116 — A guide to human zinc absorption: general overview and recent advances of in vitro intestinal models. Review of human zinc absorption: the form of zinc and the meal both change how much is absorbed.
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