Zinc
Compiled from published pharmacological and botanical literature. Not independently verified by Herbuno. Spotted an error or have a correction? Flag it below →
| Compound | Zinc (Zn) |
|---|---|
| Chemical class | Essential trace element — divalent cation (Zn2+), group 12 transition metal |
| CAS | 7440-66-6 (elemental) · salt-specific CAS applies to each form |
| Primary source | Mineral salts (gluconate, sulphate, oxide, picolinate, bisglycinate); botanical carriers include guava leaf (Psidium guajava) |
| Key applications | Immune support, skin and wound integrity, male reproductive health, taste and smell acuity, antioxidant enzyme cofactor |
| Claim strength | High for deficiency correction and cold duration; Moderate for most other indications |
| Typical form | Mineral salt powder, botanical zinc concentrate, or liposomal powder |
| Buy from Herbuno | Zinc 4% from Guava Leaf · Liposomal Zinc Bisglycinate · Liposomal Zinc Picolinate · Liposomal Zinc Oxide |
| Origin | Processed / Sourced from India |
| MOQ | R&D 100 g / 250 g (subject to stock) · Pilot batch 1–5 kg · Bulk 10 kg, 25 kg and above |
| Lead Time | Dispatch within 72 hrs from stock · fresh-batch production (typically 50 kg+): 10 working days |
| Documentation | CoA & MSDS standard with every lot; phytosanitary on request |
Name origin: The element takes its name from the German Zink, used by Paracelsus in the sixteenth century, though the metal had been smelted in India at Zawar in Rajasthan since at least the twelfth century — several hundred years before European metallurgy reproduced the process. Zawar remains the earliest known site of industrial-scale zinc distillation anywhere, and India is still among the largest primary zinc producers.
Traditional use: Zinc entered materia medica long before its nutritional role was understood. Calamine, a zinc carbonate ore, appears in Ayurvedic and Greco-Roman practice as a topical preparation for weeping skin lesions and eye complaints; the Sanskrit texts describe yashada bhasma, a calcined zinc preparation, used internally. These were empirical applications of an astringent mineral rather than deficiency correction, but the skin and mucosal indications map closely onto what is now understood about zinc's role in epithelial turnover.
Research trajectory: Zinc was shown to be essential for plant growth in the 1860s and for laboratory animals by the 1930s, but human deficiency was not described until 1961, when Ananda Prasad documented growth retardation and delayed sexual maturation in adolescent males in rural Iran whose diets were high in unleavened bread. The mechanism — phytate binding zinc into an unabsorbable complex — established the central problem in zinc nutrition, which is not dietary content but bioavailability. Research since has divided along two lines: correcting frank deficiency, where effects are large and reliable, and supplementation in replete populations, where they are smaller and more contested.
Commercial source: Supplement-grade zinc is manufactured, not extracted. Mineral salts are produced by reacting zinc oxide or carbonate with the corresponding acid; amino acid chelates such as bisglycinate are made by reacting a zinc salt with glycine under controlled conditions. Botanical zinc concentrates are a separate category: plant material with natural zinc accumulation is extracted and standardised to a declared zinc percentage, giving a food-matrix mineral for clean-label and whole-food positioning. The two routes serve different buyers and are not interchangeable on cost.
Evidence for Zinc Applications
The best-supported indication is reduction of common cold duration, and it is specific about dose and form. A meta-analysis of seven placebo-controlled trials in 575 participants with naturally acquired colds, restricted to lozenge trials delivering more than 75 mg/day of elemental zinc, found colds roughly a third shorter in the zinc arms, with a confidence interval spanning 21% to 45%. Within that analysis zinc acetate lozenges performed somewhat better than gluconate, but the difference between the two salts did not reach statistical significance, so the practical determinant is dose and contact time rather than choice of salt. [Hemilä 2017] Critically, this evidence is for lozenges dissolved in the mouth during an active cold, not for swallowed capsules and not for prevention. Formulators routinely misapply it: a 15 mg daily capsule has no claim to this literature. Claim strength: High.
Deficiency correction is the other high-confidence application, and the populations at risk are well characterised. Diets dominated by unrefined cereals and legumes carry high phytate loads, and the phytate-to-zinc molar ratio predicts absorption better than zinc content alone. Vegetarian and largely plant-based diets, which describe a large share of the Indian population and a growing share of Western consumers, sit at the higher end of that ratio. Supplementation in deficient individuals produces measurable restoration of growth velocity in children, immune competence, and taste acuity. The effect sizes are substantial precisely because the baseline is pathological; the same intervention in a replete adult does far less. Claim strength: High.
Form comparisons are where the commercial literature overpromises. Picolinate, bisglycinate, citrate, gluconate, sulphate and oxide differ in solubility, and oxide is the clear outlier at the bottom — its poor dissolution at gastric pH makes it a weak choice despite its high elemental zinc percentage and low cost. Among the remaining forms the differences in human absorption studies are modest and inconsistent, often within the noise of the isotope methods used to measure them. Bisglycinate and picolinate have the better data and the better tolerability profile, but a formulator should be sceptical of any claim that one chelate is several times more bioavailable than another; that framing usually traces to marketing rather than to a head-to-head trial. Claim strength: Moderate.
Beyond deficiency and colds, the evidence thins. Zinc is a structural or catalytic cofactor in several hundred enzymes including copper-zinc superoxide dismutase, and that biochemistry is not in doubt. Translating it into outcome claims is harder. Trials in acne, male fertility, diabetic glycaemic control and age-related macular degeneration report effects ranging from meaningful to null, with heterogeneity in dose, form, duration and baseline status that makes pooling difficult. The AREDS formulation used 80 mg/day of zinc oxide alongside antioxidants and showed benefit in a specific high-risk macular degeneration population, which is not a general eye-health claim. Claim strength: Moderate.
There is a genuine upper-limit problem that honest formulation has to respect. Sustained high zinc intake induces intestinal metallothionein, which preferentially binds copper and blocks its absorption; copper deficiency with anaemia and neurological signs is a documented consequence of chronic high-dose zinc. The EU tolerable upper intake level for adults is 25 mg/day and the US level is 40 mg/day — both well below the lozenge doses that produce the cold-duration effect, which is one reason that evidence does not transfer to daily supplementation. Any product positioned for continuous use above roughly 25 mg should carry a copper co-formulation rationale or a duration limit. Claim strength: High.
No head-to-head trial exists comparing a botanical zinc concentrate against an equivalent dose of a mineral zinc salt in humans. This is worth stating plainly because the clean-label category is built on an inference — that mineral bound in a food matrix behaves differently from an isolated salt — which is biologically plausible and commercially attractive but has not been demonstrated for zinc specifically. A botanical zinc product should be sold on label positioning, matrix cofactors and consumer preference, not on a bioavailability claim it cannot support. Claim strength: Emerging.
Sourcing zinc from Herbuno. We supply zinc across two distinct routes. Zinc 4% from Guava Leaf is a botanical concentrate for clean-label and whole-food positioning, standardised to a declared elemental zinc percentage. The liposomal range — bisglycinate, picolinate and oxide — serves formulators who need defined salt identity and predictable elemental loading.
All lots are processed in India and ship with CoA and MSDS as standard. Request a quotation for pilot or bulk quantities, or to discuss a specific assay target.
Dosage & Formulator Specification
Elemental zinc is the only figure that matters, and it is the one most often confused on specification sheets. Zinc sulphate monohydrate carries roughly 36% elemental zinc, gluconate roughly 14%, bisglycinate typically 20–25% depending on the chelation ratio, and oxide around 80%. A 100 mg declaration of zinc gluconate delivers about 14 mg of zinc, not 100 mg. Botanical concentrates are declared differently again: a 4% zinc extract delivers 40 mg of elemental zinc per gram of powder, so a 15 mg dose requires 375 mg of material, which has real consequences for capsule fill and tablet weight. Always confirm whether a supplier's assay refers to the salt or to elemental content.
Typical daily supplemental intakes sit between 8 and 15 mg of elemental zinc for general use, against an RDA of 8 mg for adult women and 11 mg for adult men. Therapeutic lozenge protocols from the cold literature run far higher — 75 mg/day and above, divided into multiple lozenges across the day — and are intended for short courses of five to seven days, not continuous use. Products should not blur these two use cases. The EU upper limit of 25 mg/day and the US limit of 40 mg/day apply to habitual intake and constrain any daily-use format.
Formulation behaviour differs sharply by form. Zinc salts are astringent and metallic, and the threshold at which that becomes objectionable is low, which is why lozenge formats need careful masking and why high-dose liquids are difficult. Zinc competes with iron, calcium and copper for shared absorption pathways, so multimineral formulations should either separate these or accept reduced absorption and dose accordingly. Phytate in a plant-protein matrix will suppress zinc absorption within the same product — relevant when zinc is added to a pea or rice protein base. Liposomal presentations exist partly to sidestep the taste problem and the gastric dissolution step; they carry a cost premium that should be justified against the specific formulation constraint rather than asserted generally.
For analytical control, specify elemental zinc by ICP-MS or ICP-OES, with heavy metals on the same run since zinc ores and some botanical accumulators can carry cadmium and lead. Moisture, particle size distribution and bulk density matter for blending uniformity in tablets and sachets. For botanical concentrates, ask for the source species, plant part and extraction solvent in addition to the zinc assay, because those determine both the regulatory classification and the residual-solvent profile. India-origin material should carry a phytosanitary certificate where the botanical route is used; purely mineral salts do not require one.
Frequently Asked Questions — Zinc
Does zinc actually shorten a cold?
The evidence supports lozenges specifically, at more than 75 mg/day of elemental zinc, started early in an active cold. A meta-analysis of seven trials in 575 people found colds around a third shorter on that protocol. It does not support swallowed capsules at typical daily doses, and it does not support prevention. The lozenge has to dissolve in the mouth, which suggests local contact matters, not just systemic zinc status.
Which zinc form should I use — picolinate, bisglycinate, gluconate or oxide?
Oxide is the one to avoid for oral supplementation; it dissolves poorly at gastric pH despite its high elemental percentage. Among the others, differences in human absorption are modest and inconsistent. Bisglycinate and picolinate have the better tolerability data and are the usual choice where gastric upset is a concern. Claims that one chelate is several times more absorbable than another generally do not rest on head-to-head human trials.
How much elemental zinc is in your 4% guava leaf extract?
Forty milligrams per gram of powder. A 15 mg elemental dose therefore needs 375 mg of extract, which is a meaningful share of a capsule fill and should be planned for at the formulation stage. We declare elemental zinc by ICP on every lot, so the figure on the CoA is the one to design against rather than a nominal label percentage.
Is a botanical zinc better absorbed than a mineral salt?
There is no head-to-head human trial demonstrating that, for zinc specifically. The idea that a mineral held in a food matrix behaves differently from an isolated salt is biologically plausible, but plausible is not the same as demonstrated. We would position a botanical zinc on clean-label, whole-food and matrix grounds rather than on a bioavailability claim that the literature does not currently support.
What is the safe upper limit for daily zinc?
Twenty-five milligrams per day in the EU and forty in the US, for habitual intake. Above that, sustained use induces intestinal metallothionein which blocks copper absorption, and copper deficiency with anaemia and neurological signs is documented at chronic high doses. Products intended for continuous daily use above roughly 25 mg should either include copper or state a duration limit.
Why source zinc from India rather than China?
Roughly 80% of raw nutraceutical ingredients originate in China, and buyers increasingly need a qualified second origin for continuity rather than price. India has long-established zinc metallurgy — industrial distillation at Zawar predates the European process by centuries — alongside a mature botanical extraction base, which means both the mineral and the plant-matrix routes can be served from one origin with a single documentation set.