Zinc - Tetracycline Interaction
Herbal: Zinc
Also Known As: Chelated Zinc, Zinc Acetate, Zinc Acexamate, Zinc Aspartate, Zinc Chelate, Zinc Chloride, Zinc Citrate, Zinc Gluconate, Zinc Glycinate, Zinc Methionate, Zinc Methionine, Zinc Murakab, Zinc Orotate, Zinc Oxide, Zinc Picolinate, Zinc Sulfate, Zinc Sulphate, Zincum Aceticum
Drug: Tetracycline
Brand names:
Sumycin, Sumycin 250, Tetrex BID, Achromycin V, Robitet, Sumycin 500, Tetra, Nor-Tet, Tetracyn, Tetrex, Achromycin, Terramycin IM

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 18, 2025
Interaction Details
Tetracycline is classified as belonging to the following category: Tetracycline Antibiotics
Zinc might reduce levels of tetracycline antibiotics.
Tetracyclines form complexes with zinc in the gastrointestinal tract, which can reduce absorption of both the tetracycline and zinc when taken at the same time. Taking zinc sulfate 200 mg with tetracycline reduces absorption of the antibiotic by 30% to 40%. Demeclocycline and minocycline cause a similar interaction. However, doxycycline does not seem to interact significantly with zinc. Advise patients to take tetracyclines at least 2 hours before, or 4-6 hours after, zinc supplements to avoid any interactions.
Interaction Rating
Likelihood of Occurrence
ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
References
- Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
- Neuvonen PJ. Interactions with the absorption of tetracyclines. Drugs 1976;11:45-54..
- Penttila O, Hurme H, Neuvonen PJ. Effect of zinc sulfate on the absorption of tetracycline and doxycycline in man. Eur J Clin Pharmacol 1975;9:131-4.
Zinc Overview

Tetracycline Overview
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Tetracycline is used to treat infections caused by bacteria including pneumonia and other respiratory tract infections; ; certain infections of skin, eye, lymphatic, intestinal, genital and urinary systems; and certain other infections that are spread by ticks, lice, mites, and infected animals. It is also used along with other medications to treat acne. Tetracycline is also used to treat plague and tuleramia (serious infections that may be spread on purpose as part of a bioterror attack). It can also be used in patients who cannot be treated with penicillin to treat certain types of food poisoning, and anthrax (a serious infection that may be spread on purpose as part of a bioterror attack). Tetracycline is in a class of medications called tetracycline antibiotics. It works by preventing the growth and spread of bacteria.
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Antibiotics such as tetracycline will not work for colds, flu, or other viral infections. Using antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.
Zinc - More Interactions
Zinc interacts with 52 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
Unknown | No interactions have been reported or no interaction data is currently available. |
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Parts of this content are provided by the Therapeutic Research Center, LLC.
DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
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Drug descriptions are provided by MedlinePlus.