Benefits
Highest Bioavailability Form
2024 Hosain et al. systematic review (Nutrients) and Gandia et al. crossover RCT both found zinc bisglycinate ~43% MORE bioavailable than zinc gluconate. Recent comparative evidence positions bisglycinate as the most absorbable zinc supplement form.
Superior GI Tolerability
The chelate structure protects zinc through gastric pH changes and from competing absorption inhibitors. Causes less GI distress than zinc sulfate or high-dose oxide. Better tolerated for chronic dosing.
Immune Support
Zinc supports T-cell function, NK cell activity, and inflammatory cytokine balance. Adequate zinc status critical for proper immune response.
Skin and Wound Healing
Zinc bisglycinate's bioavailability advantages translate to faster zinc tissue repletion — relevant for skin healing applications.
Reproductive Health
Zinc is critical for sperm production, ovulation, and reproductive hormone regulation. Zinc deficiency contributes to infertility; supplementation in deficient populations supports reproductive function.
Mechanism of action
Chelate Stability and Absorption
Bisglycinate structure: zinc ion bonded to two glycine molecules forming a 5-membered ring. Stable through gastric pH; absorbed via dipeptide transporters in addition to standard zinc transporters (ZIP family).
Reduced Absorption Inhibition
Phytates (in grains, legumes) and oxalates (in spinach, etc.) inhibit zinc absorption from typical zinc salts. Chelation protects zinc from these inhibitors — allowing better absorption when taken with meals.
Glycine Synergy (Theoretical)
Glycine itself supports collagen synthesis and immune function. Some theoretical synergy proposed though clinical evidence specific to glycine contribution is limited.
Standard Zinc Functions
All zinc forms share same fundamental biology — cofactor for >300 enzymes, zinc finger transcription factors, immune function, antioxidant via Cu/Zn-SOD.
Clinical trials
Randomized crossover study comparing zinc bisglycinate (15 mg elemental) vs zinc gluconate (15 mg elemental) for plasma zinc PK in healthy adults.
Healthy adults.
Zinc bisglycinate showed significantly higher serum zinc Cmax, AUCt, and AUCinf vs gluconate — calculated as 43.4% MORE bioavailable. Foundational comparative data.
Systematic review comparing absorption and bioavailability of zinc acetate, citrate, glycinate, gluconate, oxide, picolinate, sulfate in human studies.
Pooled across human PK trials.
Zinc glycinate and zinc gluconate ranked best-absorbed across human trials. Zinc oxide consistently worst. Picolinate competitive but not consistently superior.
About this ingredient
Zinc bisglycinate (also called zinc glycinate) is a CHELATE — zinc ion bonded with two glycine amino acid molecules. Among the most BIOAVAILABLE zinc supplement forms based on recent comparative human evidence. Elemental zinc content: ~20% by weight (1,000 mg zinc bisglycinate provides ~200 mg elemental zinc — though this is a high pure-chelate dose; typical product dose is ~75-150 mg chelate).
KEY COMPARATIVE EVIDENCE: (1) GANDIA 2007 (J Nutr) — zinc bisglycinate 43.4% more bioavailable than zinc gluconate in healthy adults; (2) HOSAIN 2024 (Nutrients) systematic review — bisglycinate among best-absorbed forms across multiple trials; (3) DiSilvestro 2015 — confirmed glycinate > gluconate in 6-week trial.
EVIDENCE-BASED USES: (1) Zinc deficiency correction (highest bioavailability); (2) Chronic zinc supplementation with good GI tolerance; (3) Immune support; (4) Reproductive health; (5) Skin/wound healing; (6) Hair loss (in zinc-deficient telogen effluvium).
CRITICAL CAUTIONS: (1) COPPER DEFICIENCY at chronic high doses (>40 mg/day) — bisglycinate's superior bioavailability means even 'moderate' label doses deliver more absorbed zinc than equivalent gluconate; monitor copper status; (2) DRUG INTERACTIONS — same as other zinc forms (tetracyclines, quinolones, bisphosphonates, iron, calcium); separate by 2 hours; (3) NASAL ZINC — FDA warning re anosmia (Zicam); avoid intranasal; (4) PREGNANCY — RDA-level safe (RDA 11 mg/day pregnancy); high-dose AVOID; (5) AREDS for AMD used zinc oxide 80 mg/day — for AMD prevention, follow AREDS2 protocol; (6) Bisglycinate is reasonable EVIDENCE-BASED choice for general supplementation if cost is comparable to gluconate/picolinate.