Can You Take Magnesium and Zinc Together? Doses, Timing and ZMA
Yes. At normal supplement doses, magnesium and zinc can be taken together without a meaningful effect on each other's absorption. Only very high zinc intake, around 142 mg a day in one study, has been shown to reduce magnesium absorption. Keep zinc under 40 mg and supplemental magnesium under 350 mg a day.
Magnesium and zinc are two of the most common minerals people supplement, and they're often sold together in one capsule. Can you take magnesium and zinc together without one cancelling out the other? For normal doses, yes.
Do they compete for absorption?
Minerals can compete for the same transport routes in the gut, which is why calcium and iron are best taken apart. Magnesium and zinc interact far less.
The NIH notes that very high zinc intake, about 142 mg a day, reduced magnesium absorption and disrupted magnesium balance in a study of healthy men. That's more than three times the 40 mg upper limit for zinc. At the 8–25 mg of zinc found in most supplements, there's no evidence of a meaningful problem.
Safe daily amounts
| Mineral | Adult RDA | Upper limit |
|---|---|---|
| Magnesium | 310–420 mg (all sources) | 350 mg from supplements |
| Zinc | 8–11 mg (all sources) | 40 mg from all sources |
Stay below both limits. Remember that the magnesium limit covers supplements only, while the zinc limit covers food and supplements together. Our magnesium dosing guide explains the difference.
What about ZMA?
ZMA is a combination of zinc, magnesium and vitamin B6, marketed to athletes for sleep, recovery and testosterone. A typical ZMA serving contains:
- Zinc: about 30 mg
- Magnesium: about 450 mg
- Vitamin B6: about 10 mg
Notice that 450 mg of magnesium is above the 350 mg upper limit for supplemental magnesium, which may cause loose stools. If you use ZMA, consider taking a partial serving, or check the label for a lower-dose version.
Research on ZMA in people who already get enough zinc and magnesium hasn't shown consistent benefits for testosterone or strength. Any benefit is most likely in people who are low in one of the minerals.
How to take them
- With food. Zinc on an empty stomach often causes nausea.
- Evening works well. Magnesium is popular at night; zinc can go with it.
- Separate from calcium and iron if you take high doses of those.
- Keep antibiotics apart. Both minerals bind tetracycline and quinolone antibiotics. Take the antibiotic at least 2 hours before or 4–6 hours after. Our interaction checker lists other combinations.
- Watch long-term zinc. Above 40 mg a day for months can cause copper deficiency. Many products add 1–2 mg of copper for this reason.
Who should be careful
- People with kidney disease shouldn't take magnesium supplements without medical advice.
- People taking penicillamine or thiazide diuretics should check with their doctor about zinc.
The bottom line
You can take magnesium and zinc together. At normal doses they don't block each other, and many people take them in the same capsule. Keep zinc under 40 mg and supplemental magnesium under 350 mg a day, take them with food, and space them away from antibiotics.
Frequently asked questions
Should I take magnesium and zinc at night?
Evening is a common choice, and magnesium is often taken then. Zinc can upset an empty stomach, so take both with or after a light meal.
Does ZMA boost testosterone?
ZMA may help if you're low in zinc or magnesium. Studies in people with adequate levels haven't shown reliable increases in testosterone or performance.
Can I take magnesium, zinc and calcium together?
High-dose calcium can compete with both. If you take more than about 500 mg of calcium, take it at a different time of day.
Sources
This page is for education and is not a substitute for advice from your doctor. Read our medical disclaimer.