Zinc Picolinate, Chelate, Citrate or Oxide: Reading the Label

Zinc on the shelf is sold in doses from 5 to 50 mg, and the difference between them is not «weaker or stronger» but «within the norm or past the upper level». Below is how to read a zinc supplement label: how picolinate, bisglycinate (chelate), citrate, gluconate, sulfate and oxide differ, how much element each form gives, why 25 mg is the boundary, what should stand next to it on a long course and how to compare two products per 10 mg.

What zinc is for, which complaints it is taken for and how to take it are in the article zinc: what it is for and its forms. This page is about the label only.

Zinc forms on the label: a table

The element share is a constant of the compound. Absorption comes from human comparisons: Wegmüller and colleagues (2014) showed zinc citrate absorbed like gluconate (~61 %) and markedly better than oxide (~50 %, and almost not at all on an empty stomach). Picolinate in a small 1987 study raised zinc levels better than citrate and gluconate, but the study is tiny and unreplicated — there is no scientific reason to pay extra for picolinate.

How much zinc a serving gives and where the limit is

Look for «elemental zinc» or «as Zn». «Zinc gluconate 50 mg» is 7 mg of zinc; «zinc picolinate 50 mg» is 10 mg; but «zinc 50 mg» without a salt name is 50 mg of element, twice the upper level. The Russian reference intake is 12 mg/day (MR 2.3.1.0253-21). The EFSA upper safe level for adults is 25 mg/day in total with food; NIH gives 40 mg. Above these figures, taken for more than a few weeks, zinc displaces copper: its stores fall, blood formation and nerves suffer. 50 mg doses are short prescribed courses, not a daily supplement.

What should and should not be next to it

• Copper (1–2 mg) in the formula is appropriate when zinc is taken for over a month at 20 mg and above; at 10–15 mg of zinc copper is not required.
• Iron and calcium in one tablet with zinc compete for absorption; in multivitamins that is unavoidable, in a targeted supplement it is a minus. More in the article on vitamin compatibility.
• Vitamin C next to zinc is a neutral pair, common in «immune» complexes; it does not make the formula better by itself.
• Sugar and sweeteners in lozenges and chewables; check if buying for a child.
• Registration. The SGR number on a Russian pack lets you check the composition against the Rospotrebnadzor register.

How to compare two products: price per 10 mg

Divide the pack price by the number of servings, then by the mg of elemental zinc per serving, and multiply by 10. Citrate and gluconate are usually the cheapest per milligram with equally good absorption; picolinate and chelate cost 1.5–3 times more without a proven advantage; oxide is cheap, but its real contribution adjusted for absorption is lower than the price suggests.

Checklist before buying

1. Find mg of elemental zinc — if only the compound mass is given, recalculate by the form's share.
2. 10–25 mg of element a day is the working range; 50 mg only as a prescribed course.
3. Form: citrate or gluconate by default; bisglycinate for a sensitive stomach; avoid oxide.
4. On a long course of ≥20 mg — copper in the formula or separately.
5. Do not take zinc in one tablet with iron if the goal is to raise zinc.
6. Calculate the price per 10 mg and compare.

Is this zinc right for you

The label tells whether a product is honest. Whether you need zinc is told by blood zinc and the picture of complaints: hair loss, acne and frequent colds have many causes besides zinc deficiency, and excess zinc harms copper. Upload your report — the service will match the form and dose to your numbers. How products are scored in this section is explained on the method page. Products with zinc and their label score are in the catalogue.