Iron Bisglycinate vs Zinc Picolinate

Mechanism

Iron is essential for hemoglobin (oxygen transport), myoglobin (muscle oxygen storage), cytochrome enzymes (electron transport chain — Complexes I, II, III, IV), cytochrome P450 enzymes (drug/hormone metabolism), catalase (H2O2 decomposition), ribonucleotide reductase (DNA synthesis), and aconitase (Krebs cycle). Iron bisglycinate (Ferrochel) uses amino acid chelation to bypass the normal DMT1/ferroportin pathway, instead being absorbed intact via PepT1 transporter. This mechanism avoids the GI side effects of ionic iron (free Fe2+ generates hydroxyl radicals via Fenton reaction in the gut lumen) and is not inhibited by phytates, tannins, or calcium.

Standard Dosing

25-36mg elemental iron (as bisglycinate) daily for deficiency correction

Timing

On empty stomach or with vitamin C for absorption. Alternate day dosing (every other day) may be superior due to hepcidin cycling. Separate from calcium, zinc, tea, coffee by 2+ hours.

Cycle Duration

Until ferritin >50 ng/mL, then reassess (typically 3-6 months). Not for ongoing supplementation unless chronic blood loss.

Side Effects

• GI distress (significantly less than ferrous sulfate)
• Constipation (less common with bisglycinate)
• Dark stools
• Nausea
• Iron overload if supplemented unnecessarily

Contraindications

• Hemochromatosis
• Iron overload conditions
• Thalassemia (without documented deficiency)
• Hemolytic anemias (unless also iron deficient)
• Chronic transfusion therapy

Best Stacking Partners

Mechanism

Zinc is a cofactor for >300 enzymes and is a structural component of >2000 transcription factors (zinc finger proteins). It is essential for: immune function (T-cell maturation, NK cell activity, neutrophil function), DNA synthesis and repair, protein synthesis, wound healing, taste/smell perception, insulin storage and secretion (zinc-insulin hexamer in beta cells), testosterone synthesis (cofactor for 17-beta-hydroxysteroid dehydrogenase), and antioxidant defense (Cu/Zn-SOD, metallothionein induction). Picolinate chelation via picolinic acid (a tryptophan metabolite) enhances intestinal absorption via DMT1 transporters.

Standard Dosing

15-30mg elemental zinc (as zinc picolinate) daily

Timing

With food to minimize nausea. Separate from iron, calcium, and copper supplements by 2 hours. NOT with high-phytate meals.

Cycle Duration

ongoing (with copper balance — see notes)

Side Effects

• Nausea (especially on empty stomach)
• Metallic taste
• Copper depletion (chronic high-dose without copper)
• Headache
• GI upset
• Reduced HDL at very high doses

Contraindications

• Copper deficiency (zinc will worsen it)
• Concurrent penicillamine therapy without separation

Best Stacking Partners