Zinc Glycinate vs Picolinate: Which Absorbs Better? (2026)
Neither is proven better. The idea that picolinate absorbs best comes from one 1987 study of 15 people, and blood zinc did not rise more on it. Glycinate beat gluconate in two small blood-zinc studies, and in one tiny unpublished test it beat picolinate too. Both come in 30 mg capsules on public testing lists, and glycinate costs less.
By Erin Rose Updated October 12, 2026 How we score
How much to take: our zinc dosage guide. Every form: zinc forms compared.
Side by side
| Zinc glycinate (bisglycinate) | Zinc picolinate | |
|---|---|---|
| What it is | Zinc bound to glycine, an amino acid | Zinc bound to picolinic acid |
| Best evidence | Two small studies: blood zinc rose more than on gluconate (12 women, one dose; 10 women a group, 6 weeks) | One study, 15 people, 1987: hair, urine and red-cell zinc rose; blood zinc did not rise more |
| Tested against each other? | Once, in a tiny unpublished test: one dose in 12 women, known only from a short abstract. Blood zinc rose most on glycinate; picolinate did no better than oxide. | |
| On a testing list | Thorne Zinc Bisglycinate 30 mg (NSF/ANSI 173) | Thorne Zinc Picolinate 30 mg and Momentous Zinc (both NSF/ANSI 173 and NSF Certified for Sport) |
| Lowest cost per 15 mg | $0.046 (NOW Zinc Glycinate 30 mg) | $0.19 (Thorne Zinc Picolinate 30 mg) |
Which absorbs better
Glycinate has a little more behind it, but none of the evidence is strong. The only head-to-head test was one dose in 12 women, never published in full; a 2024 review describes it: blood zinc rose most on glycinate, and picolinate did no better than zinc oxide (Devarshi 2024). Here is the rest.
Picolinate. In 1987, 15 people took 50 mg of zinc a day as picolinate, citrate or gluconate, 4 weeks each. On picolinate, zinc in hair, urine and red blood cells went up. On the others it did not. Blood (serum) zinc did not rise significantly on any of them (Barrie 1987). It was a small study, it measured zinc in places other than the blood, and no later study we found repeated it.
Glycinate. Two small studies compared it with zinc gluconate. In 12 women given one 15 mg dose, the rise in blood zinc was 43% larger after bisglycinate (Gandia 2007). In women taking 60 mg a day for 6 weeks, blood zinc rose in all 10 on glycinate and did not change overall in the 10 on gluconate (DiSilvestro 2015). Neither study measured absorption directly.
The best-designed study left both out. The one study we found that measured absorption directly, with tracer zinc, tested citrate, gluconate and oxide. Citrate (61.3%) and gluconate (60.9%) absorbed about the same; oxide absorbed less (49.9%) (Wegmüller 2014). A 2024 review paid for by a supplement maker says picolinate’s evidence comes from single studies (Devarshi 2024). Every form compared.
| Item | Value |
|---|---|
| NOW Zinc Glycinate 30 mg | $0.046 |
| Thorne Zinc Bisglycinate 30 mg | $0.17 |
| Thorne Zinc Picolinate 30 mg | $0.19 |
| Momentous Zinc 15 mg | $0.33 |
On Amazon: NOW Zinc Glycinate 30 mg · Thorne Zinc Bisglycinate 30 mg · Thorne Zinc Picolinate 30 mg · Momentous Zinc 15 mg
Glycinate is the cheaper form here: $0.046 per 15 mg for NOW Foods, and $0.17 for Thorne, which is on a testing list. Picolinate costs $0.19 from Thorne. Every zinc we score, including cheaper forms such as gluconate.
What matters more than the form
The dose. Adults need 8 mg (women) to 11 mg (men) a day, and the upper limit is 40 mg a day from food and supplements together (NIH). Taken for weeks, 50 mg a day or more can lower copper (NIH). How much to take.
Testing. A public testing list means an outside group checked that the bottle holds what the label says. Which zinc is on one.
Food. Most zinc labels we score say to take it with a meal, which can help if zinc makes you queasy. Food also lowers how much zinc you absorb, most of all foods high in phytate, like beans and whole grains (NIH).
Questions
Is zinc picolinate better absorbed than zinc glycinate?
Not that we can show. The only head-to-head test we know of was a single dose in 12 women, published only as a short abstract and described in a 2024 review: blood zinc rose most on glycinate, and picolinate did no better than zinc oxide (Devarshi 2024). Picolinate’s reputation comes from one 1987 study of 15 people. Hair, urine and red blood cell zinc rose on picolinate, but blood (serum) zinc did not rise more than on the other forms (Barrie 1987).
Is zinc glycinate the same as zinc bisglycinate?
On the two glycinate labels we score, yes. NOW calls its product “Zinc Glycinate”, and its label says the zinc comes from Albion’s zinc bisglycinate, the same ingredient Thorne’s Zinc Bisglycinate lists.
Which form is gentlest on the stomach?
No study we read compared stomach upset between these forms. Most labels we score say to take zinc with a meal. High doses can cause nausea and stomach upset (NIH).
Does the form matter as much as the dose?
Probably not. No study shows a health difference between forms, and every label states the zinc itself, so 30 mg of glycinate and 30 mg of picolinate give the same zinc. What matters more is the total: adults should stay at or under 40 mg a day from food and supplements together (NIH).
Sources
- Barrie SA, et al. Comparative absorption of zinc picolinate, zinc citrate and zinc gluconate in humans. Agents Actions. 1987. PubMed 3630857
- 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
- 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
- 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
- NIH Office of Dietary Supplements. Zinc fact sheet for health professionals (updated January 6, 2026; read October 12, 2026).