Zinc nausea: why zinc makes you sick and which zinc to buy
· 3 min read · By Value Servings
The typical zinc post goes: took 50 mg on an empty stomach, felt awful 20 minutes later. That is a known side effect, not an allergy. Here is how to avoid it and what to buy.
Why zinc makes you nauseous
Zinc irritates the stomach lining, especially in large doses with nothing else in the stomach. The NIH lists nausea and vomiting among the first signs of too much zinc. A 50 mg capsule on an empty stomach is close to the perfect setup for it.
What helps, in order:
- Lower the dose. 15 mg is plenty for most people who take zinc daily.
- Take it with a meal. Food reduces absorption a little but greatly reduces nausea.
- Try a chelated form such as zinc glycinate (bisglycinate). Many people tolerate it better, though it can still cause nausea at high doses.
- Avoid taking it at the same time as iron or calcium supplements, which compete for absorption.
How much zinc you need
| Amount per day | |
|---|---|
| RDA, adult men | 11 mg |
| RDA, adult women | 8 mg |
| RDA, pregnancy | 11 mg |
| Upper limit, adults (food + supplements) | 40 mg |
Most people in the US get enough zinc from food. People who may run low include vegetarians and vegans, people with gut conditions that affect absorption, heavy drinkers, and older adults. A doctor can advise whether you need a supplement at all.
The label: elemental zinc
Like magnesium, zinc is bound to another molecule. The Supplement Facts panel should list elemental zinc: Zinc (as zinc bisglycinate chelate) 15 mg. That is the dose that counts.
| Form | Zinc by weight (approx.) | Notes |
|---|---|---|
| Zinc oxide | 80% | Common in multivitamins; absorbed less well in some studies |
| Zinc gluconate | 14% | Common in cold lozenges |
| Zinc citrate | 31% | Absorbed about as well as gluconate |
| Zinc picolinate | 20% | Popular online; some people report stomach upset |
| Zinc glycinate / bisglycinate | 20–30% | Often better tolerated |
Approximate figures. The Supplement Facts panel states the actual elemental amount.
Studies comparing forms are small. Citrate and gluconate absorb similarly; oxide tends to absorb less. There is not strong evidence that one well-absorbed form produces better health results than another.
Price per 15 mg
We price zinc per 15 mg of elemental zinc and keep glycinate on its own tab:
| Product | Store | Per 15 mg elemental | vs Thorne |
|---|---|---|---|
| Nutricost Zinc Bisglycinate · 50 mg · 120 Capsules | Nutricost | $0.030 | 82% less |
| Doctor's Best High Absorption Zinc Bisglycinate, 100% Chelated · 50 mg · 90 Veggie Caps | Doctor's Best | $0.043 | 74% less |
| NOW Foods Zinc Glycinate · 120 Softgels | NOW Foods | $0.046 | 72% less |
| Piping Rock Zinc Glycinate with Pumpkin Seed Oil · 30 mg · 120 Softgels | Piping Rock | $0.048 | 71% less |
| Natural Factors Zinc Bisglycinate · 50 mg · 60 Vegetarian Capsules | Natural Factors | $0.049 | 71% less |
| Thorne Zinc Bisglycinate · 30 mg · 60 Capsules popular brand | Thorne | $0.17 | — |
Prices checked September 23, 2026. Store prices change; the price at checkout is final. See the full zinc list
Zinc and copper
High zinc intake blocks copper absorption. Taking more than 40 mg a day for months can cause copper deficiency, which can lead to anemia and nerve problems. If a doctor has you on high-dose zinc, they may add copper or monitor it. At 15 mg a day with food, this is not a typical concern.
Frequently asked questions
Why does zinc make me nauseous?
Zinc irritates the stomach, especially at high doses on an empty stomach. Lower the dose to around 15 mg and take it with food.
Is 50 mg of zinc too much?
It is above the 40 mg a day upper limit for adults. Short-term use under a doctor's direction is different, but 50 mg every day long-term is more than most people need and raises the risk of copper deficiency.
Which zinc is best: glycinate, picolinate or oxide?
For daily use, glycinate is often the easiest on the stomach. Picolinate is also well absorbed. Oxide is cheapest but absorbed less well. Dose matters more than form.
Should I take zinc in the morning or at night?
Whichever meal you eat reliably. Taking it with food matters more than the time of day.
Do I need to take copper with zinc?
Not at normal doses. At high doses over long periods, copper deficiency is a real risk; ask a doctor.
Sources
Compare zinc per 15 mg elementalEvery price on the list is worked out the same way, and checked daily.
This is general information about prices and labels, not medical advice. Ask a doctor or pharmacist before starting a supplement, especially if you are pregnant, take medication, or have a health condition. We don't sell the products; how we make money.