Safety

What should you not take with copper bisglycinate?

Last reviewed: May 2026

The short answer

Keep it separate from high-dose zinc (above 25 mg) and high-dose iron (above 18 mg) — both compete with copper for absorption, so space doses 2–4 hours apart. Tetracycline and fluoroquinolone antibiotics should also be separated (2 hours before or 4–6 hours after), since copper can bind and reduce their absorption. Very high-dose vitamin C may reduce copper absorption if taken simultaneously, though typical dietary or supplemental vitamin C isn't a concern.

Minerals that compete with copper

High-dose zinc (above 25 mg). Zinc induces metallothionein in the gut, which preferentially traps copper. This is the single most common cause of acquired copper deficiency — see taking copper with zinc.
High-dose iron (above 18 mg). Iron and copper share intestinal transporters and can compete for absorption.

Medications to separate

Tetracycline and fluoroquinolone antibiotics. Copper can chelate these drugs and reduce their effectiveness. Take copper 2 hours before or 4–6 hours after the antibiotic, following pharmacist guidance.
Penicillamine. This copper-binding drug (used in Wilson disease and rheumatoid arthritis) can be undermined by copper supplements.

Vitamin C: only at very high doses

Very high daily vitamin C (generally above 1,500 mg) may reduce copper absorption over time. Normal dietary or standard supplemental vitamin C is fine alongside copper — more in taking copper with vitamin C.

Sources

NIH Office of Dietary Supplements — Copper Fact Sheet for Health Professionals — ods.od.nih.gov