Drug & supplement interaction

Tannic Acid + Doxycycline

Doxycycline brand names: Vibra-Tabs, Vibramycin, Doryx, Monodox, Doxycin, and others.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Tannic Acid and Doxycycline in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Doxycycline states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Tannic Acid and Doxycycline

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Doxycycline and Tannic Acid in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Tannic Acid at all — not against Doxycycline, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Tannic Acid safety at a glance

Tannic Acid overall Use caution Generally used topically in small amounts, but absorption through broken skin or large burns can harm the liver.
Pregnancy Possibly Unsafe When used topically on damaged or broken skin. There is insufficient reliable information available about the safety of tannic acid when used orally during preg... Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used topically on damaged or broken skin. There is insufficient reliable information available about the safety of tannic acid when used orally during preg... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Doxycycline and Tannic Acid? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Tannic Acid and Doxycycline May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • Liver problems Worth acting on Additional detail

    Tannic Acid

    “Orally, large amounts of tannic acid can cause gastric irritation, nausea, and vomiting (11). Extensive use of tannins on burns or in enemas has been associated with fatal liver damage (11). However, this toxicity may be due to digallic acid, an impurity that is sometimes found in tannic acid (11).”

    Tannic Acid · Natural Medicines adverse-effect record, reported in burns.

    1 source cited
    1. 11. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.

    “Extensive use of tannins on burns or in enemas has been associated with fatal liver damage (11). However, this toxicity may be due to digallic acid, an impurity that is sometimes found in tannic acid (11).”

    Tannic Acid · Natural Medicines adverse-effect record, reported in burns.

    1 source cited
    1. 11. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.

    Doxycycline

    Listed in the ADVERSE REACTIONS section of the FDA label for Doxycycline. Read the label on DailyMed ›

  • Stomach upset / Vomiting / Nausea Additional detail

    Tannic Acid

    “Orally, large amounts of tannic acid can cause gastric irritation, nausea, and vomiting (11).”

    Tannic Acid · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    1 source cited
    1. 11. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.

    Doxycycline

    Listed in the ADVERSE REACTIONS section of the FDA label for Doxycycline. Read the label on DailyMed ›

Effects for Doxycycline come from the ADVERSE REACTIONS section of its FDA label; effects for Tannic Acid come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Tannic Acid in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Unsafe

When used topically on damaged or broken skin. There is insufficient reliable information available about the safety of tannic acid when used orally during pregnancy and lactation; avoid using amounts greater than those found in foods.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

How to take them

Some Doxycycline Products Have a Food Rule — Tannic Acid Should Not Break It

At least one FDA label for a product containing Doxycycline says to take it on an empty stomach. Most supplements — Tannic Acid included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Doxycycline on its own and move Tannic Acid to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Doxycycline products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

2 DOSAGE AND ADMINISTRATION Take one Doxycycline capsule (40 mg) once daily in the morning on an empty stomach, preferably at least one hour prior to or two hours after meals.

From the Dosage and Administration section of the FDA label we read for Doxycycline — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

From our Q&A

Questions About Tannic Acid or Doxycycline

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Tannic Acid or Doxycycline, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Doxycycline

This page covers Tannic Acid only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Doxycycline page lists 166 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Oleander (major) and Siberian Cocklebur (major).

By severity: 7 major · 139 moderate · 20 minor.

From our pharmacist’s overview on the Doxycycline page

“St. John's wort is the supplement I would flag first for anyone on doxycycline (Vibramycin, Doryx), because it can speed the antibiotic out of the body and leave an infection undertreated.”

Reviewed by 2 · Jul 18, 2026

Open the Doxycycline interaction page

How much people look this up

Where Tannic Acid and Doxycycline Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Tannic Acid
Steady interest

#1,080 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Doxycycline
Top 5%

#39 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Tannic Acid reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Tannic Acid and Doxycycline records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Tannic Acid

What is Tannic Acid?

  • Minor skin irritation and weeping rashes
  • Sore throat and mouth sores
  • Minor burns and blisters
  • Astringent for skin
  • Hemorrhoids

Tannic acid is a plant-derived astringent used mostly on the skin and in the mouth to dry out and tighten tissue. There is some traditional and topical use, but high-quality evidence for most uses is limited, and it can be harmful if too much is absorbed, especially on broken skin or burns.

Tannins extracted from plant sources such as oak galls, bark, and certain seeds and leaves · Topical powders and solutions, throat lozenges, gargles, suppositories, and some over-the-counter skin products

An interaction check asks whether these two react with each other — it does not ask whether Tannic Acid is a good idea for someone in your situation. Here is what our Tannic Acid record says about it on its own.

Tannic Acid: dosing

There is no well-established standard dose of tannic acid for supplement use. The amount varies widely depending on the product and how it is used (for example, a skin solution versus a lozenge).The safest approach is to follow the directions on the product label and not apply it to large areas of broken or burned skin.

From our Tannic Acid monograph — the full record covers uses, side effects and every documented interaction.

Read the full Tannic Acid monograph & all interactions
Medication

About Doxycycline

What Is Doxycycline Used For?

Brand names: Vibra-Tabs, Vibramycin, Doryx, Monodox, Doxycin, Doxy, Doxylin, Doxy-D, Periostat, Doxycycline Injection, Oracea, Xyrosa

Doxycycline belongs to the tetracycline family of antibiotics. It's prescribed for many types of bacterial infections, including respiratory tract infections, sexually transmitted infections (STIs), tick-borne illnesses like Rocky Mountain spotted fever, and eye infections. It's also used to help prevent malaria and, in some cases, as a helper treatment for severe acne.

In situations where penicillin-type antibiotics can't be used — due to allergy, for example — doxycycline can step in as an alternative. It should only be used for infections that are proven or strongly suspected to be caused by bacteria.

See full Doxycycline drug information
Keep checking

Other Drugs & Tannic Acid

Browse every other medication we’ve checked against Tannic Acid — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

We also checked Tannic Acid against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Tannic Acid list.

See the full Tannic Acid interactions page
See every supplement checked against Doxycycline, ranked by severity
Evidence & sources

Tannic Acid References

The 8 references that drive our Tannic Acid monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  2. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  3. Covington TR, et al. Handbook of Nonprescription Drugs. 11th ed. Washington, DC: American Pharmaceutical Association, 1996.
  4. Laslett, L. L., Quinn, S. J., Darian-Smith, E., Kwok, M., Fedorova, T., Korner, H., Steels, E., March, L., and Jones, G. Treatment with 4Jointz reduces knee pain over 12 weeks of treatment in patients with clinical knee osteoarthritis: a randomised contr
  5. Smith DB, Jacobson BH. Effect of a blend of comfrey root extract (Symphytum officinale L.) and tannic acid creams in the treatment of osteoarthritis of the knee: randomized, placebo-controlled, double-blind, multiclinical trials. J Chiropr Med. 2011;10(3) PubMed
  6. Goh CL, Yoyong K. A comparison of topical tannic acid versus iontophoresis in the medical treatment of palmar hyperhidrosis. Singapore Med J. 1996;37(5):466-8.
  7. Kołodziej M, Bebenek D, Konarska Z, Szajewska H. Gelatine tannate in the management of acute gastroenteritis in children: a randomised controlled trial. BMJ Open. 2018;8(5):e020205. PubMed
  8. Mennini M, Tolone C, Frassanito A, Midulla F, Cucchiara S, Aloi M. Gelatin tannate for acute childhood gastroenteritis: a randomized, single-blind controlled trial. Paediatr Drugs. 2017 Apr;19(2):131-137. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Tannic Acid and Doxycycline Together: Common Questions

Is it safe to take Tannic Acid with Doxycycline?
We do not list a known interaction between Tannic Acid and Doxycycline. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Tannic Acid and Doxycycline have any of the same side effects?
Yes — our sources link each of them separately to 4 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Should I take Tannic Acid and Doxycycline at the same time of day?
At least one FDA label for a product containing Doxycycline says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Doxycycline on its own and move Tannic Acid to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
Does Doxycycline interact with any supplements?
Yes. Doxycycline has documented interactions with 166 supplements in our database — Tannic Acid is not one of them. The Doxycycline interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Tannic Acid monograph Uses, safety profile, and every drug interaction in one place Doxycycline drug information The full plain-English guide to this medication Doxycycline supplement interactions Every supplement checked against Doxycycline, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 8 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Doxycycline and Tannic Acid?

Our pharmacists answer your medication & supplement questions — free.

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.