What Is Zinc Glycinate, Picolinate & Bisglycinate For?
All three are everyday zinc supplements: they are for getting zinc, and glycinate and bisglycinate are the same thing. Neither glycinate nor picolinate is proven better than the other or than cheaper forms. In the one direct absorption test, citrate and gluconate absorbed about 61% and oxide 50%. Pick on dose, testing and price.
By Erin Rose Updated October 12, 2026 How we score
How much to take: our zinc dosage guide. Just these two: glycinate vs picolinate.
Every zinc form, and what it is for
| Form | Used in | Zinc by weight | What the human studies show |
|---|---|---|---|
| Zinc glycinate (bisglycinate) | Daily capsules and softgels | About 20% in the Albion ingredient on the labels we score (30 mg of zinc from 150 mg); 31% for the pure compound | Two small studies against gluconate: after one 15 mg dose, the rise in blood zinc was 43% larger (12 women); at 60 mg a day for 6 weeks, blood zinc rose in all 10 women on glycinate and did not change overall on gluconate. Neither measured absorption directly. |
| Zinc picolinate | Daily capsules | 21% | One 1987 study of 15 people at 50 mg a day: zinc in hair, urine and red blood cells rose on picolinate and not on citrate or gluconate; blood (serum) zinc did not rise significantly on any of them. In one small unpublished single-dose test (12 women), picolinate did no better than oxide. |
| Zinc citrate | Daily capsules and tablets | 32% to 34%, depending on the water in the compound | Absorbed 61.3% in the stable-isotope study, about the same as gluconate and more than oxide. |
| Zinc gluconate | Daily tablets and most cold lozenges | 14% | Absorbed 60.9% in the stable-isotope study, about the same as citrate. One of the two lozenge forms in the cold trials. |
| Zinc acetate | Cold lozenges | 30% | The other lozenge form in the cold trials. In a meta-analysis, acetate lozenges shortened colds by 40% and gluconate lozenges by 28%; the difference was not significant. |
| Zinc sulfate | Low-cost tablets; many older studies | 23% to 36%, depending on the water in the compound | One of the forms NIH names as common in supplements. Not in the stable-isotope study above. |
| Zinc oxide | Low-cost tablets and multivitamins; also sunscreen | 80% | Absorbed 49.9% in the stable-isotope study, less than citrate or gluconate; 3 of the 15 people absorbed little or none. |
Which form absorbs best
- Zinc citrate61.3%
- Zinc gluconate60.9%
- Zinc oxide49.9%
Stable-isotope study of 15 healthy adults, each taking all three forms without food. The only direct absorption test of these forms we found; glycinate and picolinate were not in it. Source: Wegmüller 2014, PubMed 24259556.
The best evidence is narrow. In the study above, citrate and gluconate absorbed about the same, and oxide less; three of the 15 people absorbed little or no zinc from oxide (Wegmüller 2014). NIH repeats these figures. The study gave zinc without food, which raises absorption.
For glycinate and picolinate there are only small studies that measured zinc in the blood or body, not absorption itself. Glycinate beat gluconate in two of them (Gandia 2007; DiSilvestro 2015). Picolinate’s reputation rests on one 1987 study of 15 people (Barrie 1987). A 2024 review paid for by Pharmavite, the maker of Nature Made, concluded that glycinate and gluconate absorb better than other forms (Devarshi 2024). No study we found shows that any form works better for your health.
Reading the label: the zinc, not the compound
A zinc compound is part zinc and part something else, and the share varies a lot: oxide is 80% zinc, gluconate only 14%. You do not need the math. In the U.S., the Supplement Facts panel lists the zinc itself, not the weight of the whole compound (NIH). “Zinc 30 mg (as zinc gluconate)” means 30 mg of zinc.
That is why a 30 mg gluconate tablet and a 30 mg glycinate capsule give you the same zinc. Compare products on the “Zinc” line and the cost, and keep your total at or under 40 mg a day from food and supplements together (NIH).
Lozenges are a different product
The cold trials used lozenges that dissolve in the mouth, made with zinc acetate or zinc gluconate. Acetate lozenges shortened colds by 40% and gluconate lozenges by 28% in one meta-analysis; the difference was not significant. The doses that worked were over 75 mg a day, above the 40 mg daily limit, so they are for the days of a cold only (Hemilä 2017). A zinc capsule you swallow is not the same thing. Zinc for colds.
| Item | Value |
|---|---|
| Nature Made Zinc 30 mg | $0.029 |
| NOW Zinc Glycinate 30 mg | $0.046 |
| Solgar Zinc Citrate 30 mg | $0.049 |
| Thorne Zinc Bisglycinate 30 mg | $0.17 |
| Thorne Zinc Picolinate 30 mg | $0.19 |
| Garden of Life Vitamin Code Raw Zinc | $0.19 |
| Momentous Zinc 15 mg | $0.33 |
On Amazon: Nature Made Zinc 30 mg · NOW Zinc Glycinate 30 mg · Solgar Zinc Citrate 30 mg · Thorne Zinc Bisglycinate 30 mg · Thorne Zinc Picolinate 30 mg · Garden of Life Vitamin Code Raw Zinc · Momentous Zinc 15 mg
The cheapest zinc we score, Nature Made’s gluconate at $0.029 per 15 mg, is also on a testing list. Glycinate starts at $0.046 (NOW Foods, not on a list). Picolinate and the tested glycinates cost several times more. Our picks, by need.
Questions
What is zinc glycinate for?
The same thing as any zinc supplement: getting zinc, which supports immune function, wound healing and taste (NIH). Glycinate is zinc bound to glycine, an amino acid. In two small studies it raised blood zinc more than gluconate.
Is zinc bisglycinate the same as zinc glycinate?
Yes, in practice. Bisglycinate is the full chemical name (zinc bound to two glycines). On the two glycinate labels we score, NOW calls it glycinate and Thorne calls it bisglycinate, and both list the same Albion ingredient.
What is zinc picolinate for?
Also everyday zinc. Its reputation for absorbing best comes from one 1987 study of 15 people, which measured zinc in hair, urine and red blood cells; blood zinc did not rise significantly on any form (Barrie 1987).
Which zinc form is best absorbed?
In the one study that measured absorption directly, citrate (61%) and gluconate (61%) absorbed about the same, and oxide less (50%) (Wegmüller 2014). Glycinate and picolinate were not in that study.
Which form is best for a cold?
Lozenges, not capsules. The cold trials used zinc acetate or gluconate lozenges at over 75 mg a day (Hemilä 2017). See zinc for colds.
Sources
- Wegmüller R, et al. Zinc absorption by young adults from supplemental zinc citrate is comparable with that from zinc gluconate and higher than from zinc oxide. J Nutr. 2014. PubMed 24259556
- Gandia P, et al. A bioavailability study comparing two oral formulations containing zinc (Zn bis-glycinate vs. Zn gluconate) after a single administration to twelve healthy female volunteers. Int J Vitam Nutr Res. 2007. PubMed 18271278
- DiSilvestro RA, et al. Moderately high dose zinc gluconate or zinc glycinate: effects on plasma zinc and erythrocyte superoxide dismutase activities in young adult women. Biol Trace Elem Res. 2015. PubMed 25877802
- Barrie SA, et al. Comparative absorption of zinc picolinate, zinc citrate and zinc gluconate in humans. Agents Actions. 1987. PubMed 3630857
- Devarshi PP, et al. Comparative absorption and bioavailability of various chemical forms of zinc in humans: a narrative review. Nutrients. 2024. Funded by Pharmavite. PubMed 39770891
- Hemilä H. Zinc lozenges and the common cold: a meta-analysis comparing zinc acetate and zinc gluconate, and the role of zinc dosage. JRSM Open. 2017. PubMed 28515951
- NIH Office of Dietary Supplements. Zinc fact sheet for health professionals (updated January 6, 2026; read October 12, 2026).
- Zinc share by weight: calculated from molecular weights (zinc 65.38). Glycinate: NOW Zinc Glycinate label, NIH label database 314226.