Drug & supplement interaction

Tormentil + Doxycyline

Doxycyline brand name: Doxychel.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Tormentil and Doxycyline 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 Doxycyline 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

Tormentil and Doxycyline

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 Doxycyline and Tormentil 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 Tormentil at all — not against Doxycyline, 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.

Tormentil safety at a glance

Tormentil overall Use caution Generally considered low-risk for short-term use, but human safety data are limited.
Pregnancy Avoid Not enough safety information, so it is best avoided during pregnancy.
Breastfeeding Avoid Safety has not been studied, so avoid use while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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

No Interaction Found — But Data Suggests Tormentil and Doxycyline May Share a Side Effect

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.

  • Stomach pain Additional detail

    Tormentil

    “Orally, tormentil has been reported to cause mild abdominal pain, heartburn, and feelings of fullness in one clinical trial. These adverse effects occurred at the same frequency for doses ranging from 1.2 grams daily to 3 grams daily.”

    Tormentil · Natural Medicines adverse-effect record, reported in dyspepsia.

    1 source cited
    1. 78590. Huber, R., Ditfurth, A. V., Amann, F., Guthlin, C., Rostock, M., Trittler, R., Kummerer, K., and Merfort, I. Tormentil for active ulcerative colitis: an open-label, dose-escalating study. J.Clin.Gastroenterol. 2007;41(9):834-838. PubMed

    Doxycyline

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

Reported for Tormentil but not commonly for Doxycyline: heartburn.

Effects for Doxycyline come from the ADVERSE REACTIONS section of its FDA label; effects for Tormentil 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.

How to take them

Some Doxycyline Products Have a Food Rule — Tormentil Should Not Break It

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

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Tormentil or Doxycyline, 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 Doxycyline

This page covers Tormentil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Doxycyline page lists 149 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Asarabacca (major), Beer (major), Oleander (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 132 moderate · 11 minor.

From our pharmacist’s overview on the Doxycyline page

“I read the supplement list for doxycycline (Doxychel) as one to approach with real care, starting with its major-rated entries. Heavy alcohol, including beer and wine, adds to the liver strain this antibiotic can cause, botanicals such as Siberian cocklebur can compound stress on the kidneys, and St.”

Reviewed by 2 · Jul 18, 2026

Open the Doxycyline interaction page

How much people look this up

Where Tormentil and Doxycyline 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 Tormentil
Steady interest

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

29 days ago today
Medication Doxycyline
Top 25%

#554 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 Tormentil reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Tormentil and Doxycyline 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 Tormentil

What is Tormentil?

  • Diarrhea
  • Mouth and throat inflammation
  • Mild digestive upset
  • Sore throat (gargle)
  • Minor wounds and skin irritation

Tormentil is a traditional herb whose root is rich in tannins and has long been used for diarrhea and as a mouth rinse for sore gums or throat. Some small studies suggest it may help shorten diarrhea, but overall evidence is limited and quality is low. Talk to your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding because safety is not established.

Potentilla erecta · Rosaceae · Root and rhizome (underground stem) · Tincture, liquid extract, tea, capsules, mouth rinse

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

Tormentil: dosing

There is no official, standardized dose for tormentil, and products vary widely in strength. Tinctures, extracts, teas, and capsules will each have different recommended amounts.The safest approach is to follow the directions on the product label and not exceed them. If you are using it as a mouth rinse, do not swallow large amounts.

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

Read the full Tormentil monograph & all interactions
Medication

About Doxycycline

What Is Doxycycline Used For?

Brand name: Doxychel

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 & Tormentil

Browse every other medication we’ve checked against Tormentil — 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
No interaction 2,829 drugs checked — show the list
Evidence & sources

Tormentil References

The 1 references that drive our Tormentil 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. Huber, R., Ditfurth, A. V., Amann, F., Guthlin, C., Rostock, M., Trittler, R., Kummerer, K., and Merfort, I. Tormentil for active ulcerative colitis: an open-label, dose-escalating study. J.Clin.Gastroenterol. 2007;41(9):834-838. 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 Tormentil and Doxycyline Together: Common Questions

Is it safe to take Tormentil with Doxycyline?
We do not list a known interaction between Tormentil and Doxycyline. 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 Tormentil and Doxycyline have any of the same side effects?
Yes — our sources link each of them separately to one 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 Tormentil and Doxycyline at the same time of day?
At least one FDA label for a product containing Doxycyline 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 Doxycyline on its own and move Tormentil 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 Doxycyline interact with any supplements?
Yes. Doxycyline has documented interactions with 149 supplements in our database — Tormentil is not one of them. The Doxycyline interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Doxycyline and Tormentil?

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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.