Drug & supplement interaction

Gumweed + Levonorgestrel

Levonorgestrel brand names: Plan B, Mirena, Levonelle One Step, Levonelle 1500, Norgeston, and others.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Oct 4, 2026
The bottom line No known interaction

We found no known interaction between Gumweed and Levonorgestrel 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.

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Interaction report

Gumweed and Levonorgestrel

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 Levonorgestrel and Gumweed 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 Gumweed at all — not against Levonorgestrel, 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.

Gumweed safety at a glance

Gumweed overall Use caution Generally used in small amounts traditionally, but human safety data are limited.
Pregnancy Avoid Not enough safety information, so it is best avoided.
Breastfeeding Avoid Safety while breastfeeding is unknown, so avoid use.

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

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

What Gumweed Itself Has Been Linked To

This is not an interaction — nothing below involves Levonorgestrel. It is the side-effect record for Gumweed on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Gumweed, this list is the first place to look.

  • Diarrhea Additional detail

    “Orally, gumweed seems to be well tolerated. It can cause gastric mucosal irritation (2,12), diarrhea (18), and kidney irritation (12).”

    Gumweed · Natural Medicines adverse-effect record, reported in diarrhea.

    3 sources cited
    1. 2. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
    2. 12. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
    3. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

    “Orally, gumweed can cause gastric mucosal irritation (2,12) and diarrhea (18).”

    Gumweed · Natural Medicines adverse-effect record, reported in diarrhea.

    3 sources cited
    1. 2. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
    2. 12. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
    3. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

Everything above comes from the Natural Medicines adverse-effect record for Gumweed — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Levonorgestrel’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Levonorgestrel column appears here.

From our Q&A

Questions About Gumweed or Levonorgestrel

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

This page covers Gumweed only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Levonorgestrel page lists 191 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 6 major · 142 moderate · 43 minor.

From our pharmacist’s overview on the Levonorgestrel page

“St. John's wort tops my worry list for anyone using levonorgestrel (Plan B, Mirena, and other birth control).”

Reviewed by 2 · Jul 18, 2026

Open the Levonorgestrel interaction page

One more smart check

Taking Gumweed as Part of a Dietary Supplement Product? Check It for Interactions

We hold 18 real supplement products containing Gumweed, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Gumweed. Even though Gumweed itself has no known interaction with Levonorgestrel, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Gumweed and Levonorgestrel 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 Gumweed
Steady interest

#1,435 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Levonorgestrel
Top half

#761 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 Gumweed reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified October 4, 2026. The Gumweed and Levonorgestrel 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 Gumweed

What is Gumweed?

  • Cough and bronchitis
  • Asthma-related breathing problems
  • Skin irritation from poison ivy or poison oak
  • Minor wounds and rashes
  • Upper respiratory congestion

Gumweed is a traditional North American plant used mostly for coughs, chest congestion, and skin irritation such as poison ivy rashes. Good-quality human studies are lacking, so its benefits are not well proven, and it should be used cautiously and avoided during pregnancy and breastfeeding.

Grindelia robusta · Asteraceae · Dried leaves and flowering tops · Tea, tincture, liquid extract, capsules, topical preparations

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

Gumweed: dosing

There is no well-established, standardized dose for gumweed. Traditional preparations include teas, tinctures, and liquid extracts, but the strength of commercial products varies widely.The safest approach is to follow the directions on the product label and not exceed the suggested amount.

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

Read the full Gumweed monograph & all interactions
Medication

About Levonorgestrel

What Is Levonorgestrel Used For?

Brand names: Plan B, Mirena, Levonelle One Step, Levonelle 1500, Norgeston, Skyla, Liletta, Kyleena

Levonorgestrel is used in two very different ways, depending on the product.

The intrauterine systems (Mirena, Liletta, Kyleena and Skyla) prevent pregnancy for a set number of years. Mirena and Liletta are also used to treat heavy menstrual bleeding in women who choose intrauterine contraception. The oral tablets are used for emergency contraception, to reduce the chance of pregnancy after unprotected sex.

Most-Reported Side Effects for Levonorgestrel

From FAERS, the FDA’s public side-effect reporting system (206,325 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Device expulsion 45,536 reports
Device dislocation 20,447 reports
Menstruation irregular 15,061 reports
Vaginal haemorrhage 15,056 reports
Genital haemorrhage 11,164 reports
See full Levonorgestrel drug information
Keep checking

Other Drugs & Gumweed

Browse every other medication we’ve checked against Gumweed — 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 Gumweed 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 Gumweed list.

See the full Gumweed interactions page
See every supplement checked against Levonorgestrel, ranked by severity
Evidence & sources

Gumweed References

The 3 references that drive our Gumweed 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. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  3. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

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 Gumweed and Levonorgestrel Together: Common Questions

Is it safe to take Gumweed with Levonorgestrel?
We do not list a known interaction between Gumweed and Levonorgestrel. 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.
Does Levonorgestrel interact with any supplements?
Yes. Levonorgestrel has documented interactions with 191 supplements in our database — Gumweed is not one of them. The Levonorgestrel 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

Gumweed monograph Uses, safety profile, and every drug interaction in one place Levonorgestrel drug information The full plain-English guide to this medication Levonorgestrel supplement interactions Every supplement checked against Levonorgestrel, 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 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Levonorgestrel and Gumweed?

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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.