What do the states mean?+
- Solid: well studied, and it works.
- Half-there: the science is still forming.
- A ghost: almost no real studies.
- Hollow: well studied, and it does not work.
- A cord: the pair itself has been tested together.
- Air: nobody has ever tested this pair.
The full scoring method: How we score
Can you take iron and zinc together?
You don’t need to take them together.
As of August 2026, iron and zinc have been tested together in 129 trials, and no clear added effect was found. Scored under the same rules as everything here.
137 studies · 129 tested the actual pair · 1 caution
What you’re seeing
- Iron renders solid: for anaemia and iron levels, it is well studied and it works.
- Zinc renders hollow: for immunity and colds, it is well studied and it does not work.
- The woven cord is the rare part: 129 trials gave both together, and no clear added effect was found.
You can tell before you read a word.
Magnesium + L-theanine are sold together in the same aisle. No trial has ever tested the pair. When that is true, we draw nothing between them. The nothing is the review.
The pooled pair trials
- 2023Meta-analysis · children and adolescents under 20 given oral iron · no clear effectsource
The other 8 studies on file tested each one alone. See all 137 studies
Fair questions
Is it safe to take iron and zinc together?+
The studies on this page gave both together and reported no harm from the combination. That is not the same as a safety trial, and it says nothing about your dose or your medication.
How many studies is this based on?+
1 that gave the pair together. The papers are listed above with links to the source.
Deeper
What each one is on its own+
Iron
- Anaemia and iron levelssolid
- Memory and focushalf-there
Zinc
- Immunity and coldshollow
- Gut and digestionhalf-there
- Moodhalf-there
- Premenstrual symptomsa ghost
- Skin, hair and nailshalf-there
- Stress and anxietya ghost
Pairs that have been tested+
- Iron has been tested with taurine, vitamin D, turmeric, green tea extract, vitamin C.
- Zinc has been tested with melatonin, folate, turmeric, inositol.
These are the combinations someone has actually run a study on. Every other pairing here is air.
Worth knowing+
- Zinc taken for a cold probably causes more side effects than placebo: unpleasant taste, nausea, stomach cramps and diarrhoea were 34 percent more common across 16 treatment trials. The doses used in those trials, 45 to 276 mg a day, are far above the amount in a daily multivitamin.