Zinc supplements
With zinc the risk is too much, not too little. Each product is judged on the zinc a day its directions give: at least the RDA, 11 mg for men (8 mg for women), and no more than the US upper limit of 40 mg a day, set because more can lower copper. Products over the limit are flagged. Commission never changes the order.
Capsules (6)
| Product | Per serving | Servings a day | Per day, as directed | Verdict | Proof |
|---|---|---|---|---|---|
| BulkSupplements.com Zinc Picolinate Softgels 11 mg · label 24 Apr 2025 | 11 mg in 1 capsule | 1 serving | 11 mg | Meets the RDA | Label claim only |
| Pure Encapsulations Zinc 30 · label 18 Jul 2023 | 30 mg in 1 capsule | 1 serving | 30 mg | Meets the RDA | Label claim only |
| Swanson Chelated Zinc 30 mg · label 21 Dec 2024 | 30 mg in 1 capsule | 1 serving | 30 mg | Meets the RDA | Label claim only |
| Thorne Zinc Picolinate 30 mg · label 22 Jun 2023 | 30 mg in 1 capsule | 1 serving | 30 mg | Meets the RDA | Label claim only |
| Nutricost Zinc Gluconate 50 mg · label 24 Jan 2024 | 50 mg in 1 capsule | 1 serving | 50 mg | Over the upper limit | Label claim only |
| Sports Research Zinc Picolinate 50 mg · label 24 Apr 2025 | 50 mg in 1 capsule | 1 serving | 50 mg | Over the upper limit | Label claim only |
Tablets (5)
| Product | Per serving | Servings a day | Per day, as directed | Verdict | Proof |
|---|---|---|---|---|---|
| GNC Zinc 30 mg · label 23 Feb 2022 | 30 mg in 1 tablet | 1 serving | 30 mg | Meets the RDA | Label claim only |
| Nature Made Zinc 30 mg · label 13 Dec 2022 | 30 mg in 1 tablet | 1 serving | 30 mg | Meets the RDA | USP Verified |
| NaturesPlus Zinc 30 mg · label 22 Nov 2023 | 30 mg in 1 tablet | 1 serving | 30 mg | Meets the RDA | Label claim only |
| Nature's Bounty Zinc 50 mg · label 22 Mar 2024 | 50 mg in 1 tablet | 1 serving | 50 mg | Over the upper limit | Label claim only |
| Spring Valley Zinc 50 mg · label 25 Jun 2025 | 50 mg in 1 tablet | 1 serving | 50 mg | Over the upper limit | Label claim only |
Liquids (1)
| Product | Per serving | Servings a day | Per day, as directed | Verdict | Proof |
|---|---|---|---|---|---|
| MaryRuth's Organic Ionic Zinc Liquid Drops · label 11 Oct 2026 | 11 mg in one serving | 1 serving | 11 mg | Meets the RDA | Label claim only |
12 products. Where the directions give a range, the verdict judges the most they give in a day. Read the zinc guide for the studies behind the dose. "Proof" is a published independent lab test, a certifier listing we read on the certifier's own site (usually for listed lots only), or "Label claim only" when we found neither.
Why the 40 mg limit, and what studies used
Too much zinc lowers copper. In healthy men, 50 mg of zinc a day (two doses of 25 mg) for 6 weeks lowered a marker of copper status (Fischer et al., 1984). The US upper limit of 40 mg a day counts all zinc, from food, multivitamins and lozenges as well; the EU's is 25 mg (Schoofs et al., 2024).
Some trials used more for a set time and under study conditions: 45 mg a day for a year in older adults (Prasad et al., 2007), and 80–92 mg a day as lozenges for a few days during a cold (Hemilä, 2017). Those are why some products sell 50 mg, but a page here never counts going past the upper limit as a target.
Research context, not advice.