Drug & supplement interaction

Clubmoss + Acetaminophen

Acetaminophen brand names: Tylenol Ex Strength, Children's Tylenol, Tylenol, Children's Tylenol Meltaways.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Clubmoss and Acetaminophen 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 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

Clubmoss and Acetaminophen

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 Acetaminophen and Clubmoss 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.

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.

Clubmoss safety at a glance

Clubmoss overall Use caution It contains toxic alkaloids and has limited safety data, so it should be used carefully if at all.
Pregnancy Possibly Unsafe When used orally; avoid using. Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used orally; avoid using. 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 Acetaminophen and Clubmoss? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Acetaminophen

Interactions in our licensed database are recorded against drug classes, not just single drug names. Acetaminophen is filed under 8 classifications — including cytochrome p450 2e1 (cyp2e1) substrates, glucuronidated drugs, cytochrome p450 1a2 (cyp1a2) substrates. Clubmoss has documented interactions with 3 drug classes — the most serious being acetylcholinesterase (ache) inhibitors (moderate), anticholinergic drugs (moderate) and cholinergic drugs (moderate) — and none of Acetaminophen’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Clubmoss Does Interact With Other Medications

Clubmoss has 219 moderate known drug interactions in our database — Acetaminophen isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Clubmoss

Covers the 2,830 medications we’ve checked against Clubmoss. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Clubmoss and Acetaminophen 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.

  • Wheezing Worth acting on Additional detail

    Clubmoss

    “Orally, no adverse effects have been reported; however, a thorough evaluation of safety outcomes has not been conducted. Additionally, clubmoss contains toxic alkaloids, which could cause serious adverse effects. When fir club moss (Lycopodium selago) is mistaken for clubmoss, cholinergic toxicity has been reported.”

    Clubmoss · Natural Medicines adverse-effect record, reported in asthma.

    2 sources cited
    1. 43721. Cullinan, P., Cannon, J., Sheril, D., and Newman, Taylor A. Asthma following occupational exposure to Lycopodium clavatum in condom manufacturers. Thorax 1993;48(7):774-775. PubMed
    2. 13193. Felgenhauer N, Zilker T, Worek F, Eyer P. Intoxication with huperzine A, a potent anticholinesterase found in the fir club moss. J Toxicol Clin Toxicol 2000;38:803-8.. PubMed

    “Occupational exposure to clubmoss spores, including cases associated with facilities that use the spores to coat condoms, has been reported to cause asthma.”

    Clubmoss · Natural Medicines adverse-effect record, reported in asthma.

    1 source cited
    1. 43721. Cullinan, P., Cannon, J., Sheril, D., and Newman, Taylor A. Asthma following occupational exposure to Lycopodium clavatum in condom manufacturers. Thorax 1993;48(7):774-775. PubMed

    Acetaminophen

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

  • Nausea reported in 6.2% of FDA reports for Acetaminophen Additional detail

    Clubmoss

    “Clubmoss (Lycopodium clavatum) might be mistaken for fir club moss (Lycopodium selago), which contains huperzine A, a constituent with strong inhibitory activity against acetylcholinesterase. In two case reports, fir club moss was mistaken for clubmoss and ingested as tea. This caused cholinergic toxicity with symptoms of sweating, nausea, dizziness, cramping, and slurred speech.”

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

    1 source cited
    1. 13193. Felgenhauer N, Zilker T, Worek F, Eyer P. Intoxication with huperzine A, a potent anticholinesterase found in the fir club moss. J Toxicol Clin Toxicol 2000;38:803-8.. PubMed

    Acetaminophen

    Listed in the ADVERSE REACTIONS section of the FDA label for Acetaminophen, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Clubmoss but not commonly for Acetaminophen: dizziness and sweating.

Effects for Acetaminophen come from the ADVERSE REACTIONS section of its FDA label; effects for Clubmoss come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 679,604 voluntary FDA FAERS reports for Acetaminophen that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Clubmoss in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Unsafe

When used orally; avoid using.

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

From our Q&A

Questions About Clubmoss or Acetaminophen

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

This page covers Clubmoss only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen page lists 155 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), Siberian Cocklebur (major) and Wine (major).

By severity: 5 major · 114 moderate · 36 minor.

From our pharmacist’s overview on the Acetaminophen page

“Acetaminophen (Tylenol) feels harmless because it sits on every shelf, but this list deserves real attention, mostly because of your liver. Of the 155 supplements and herbs on file, five carry a major rating, and the largest serious group, 38 ingredients, adds liver strain on top of acetaminophen's own well-known potential to harm the…”

Reviewed by 2 · Jul 18, 2026

Open the Acetaminophen interaction page

How much people look this up

Where Clubmoss and Acetaminophen 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 Clubmoss
Steady interest

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

29 days ago today
Medication Acetaminophen
Top 1%

#18 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 Clubmoss reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Clubmoss and Acetaminophen 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 Clubmoss

What is Clubmoss?

Clubmoss
  • Bladder and kidney complaints
  • Digestive upset
  • Skin irritation and chafing
  • Respiratory problems
  • Used in homeopathy

Clubmoss (Lycopodium clavatum) is a primitive plant with a long history in folk medicine and homeopathy, but there is very little reliable human research to show it works for any health condition. It contains potentially toxic alkaloids, so it should be used with great caution, and people who are pregnant or breastfeeding should avoid it. Talk with a pharmacist or doctor before trying it.

Lycopodium clavatum · Lycopodiaceae · Whole plant and spores · Powdered spores, dried herb, tinctures, teas, homeopathic preparations, capsules

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

Clubmoss: dosing

There is no established, well-studied dose for clubmoss. Because the amount of active and potentially toxic compounds can vary between products and plant sources, a safe dose has not been clearly defined.If you choose to use a clubmoss product, follow the directions on the label and do not exceed them. Homeopathic "Lycopodium" products are extremely diluted and are different from raw herb preparations.

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

Read the full Clubmoss monograph & all interactions
Medication

About Acetaminophen

What Is Acetaminophen Used For?

Brand names: Tylenol Ex Strength, Children's Tylenol, Tylenol, Children's Tylenol Meltaways

Acetaminophen temporarily relieves minor aches and pains caused by headaches, the common cold, backaches, muscle aches, toothaches, minor arthritis pain, and premenstrual or menstrual cramps. It also temporarily reduces fever.

These uses apply across oral tablet, suspension, and oral liquid products. The intravenous (IV) injection form is used in clinical settings to treat acute pain and fever, including in pediatric patients 2 years and older.

Most-Reported Side Effects for Acetaminophen

From FAERS, the FDA’s public side-effect reporting system (679,604 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 45,791 reports
Nausea 41,932 reports
Overdose 40,941 reports
Drug dependence 39,209 reports
Headache 38,738 reports
See full Acetaminophen drug information
Keep checking

Other Drugs & Clubmoss

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

0Major
219Moderate
0Minor
2,610No known interaction
Moderate

219 interactions

Showing 60 of 219 moderate interactions — see all 219 on the Clubmoss page.

No interaction 2,610 drugs checked — show the list
Evidence & sources

Clubmoss References

The 3 references that drive our Clubmoss 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. Felgenhauer N, Zilker T, Worek F, Eyer P. Intoxication with huperzine A, a potent anticholinesterase found in the fir club moss. J Toxicol Clin Toxicol 2000;38:803-8.. PubMed
  2. Orhan, I., Terzioglu, S., and Sener, B. Alpha-onocerin: an acetylcholinesterase inhibitor from Lycopodium clavatum. Planta Med. 2003;69(3):265-267.
  3. Cullinan, P., Cannon, J., Sheril, D., and Newman, Taylor A. Asthma following occupational exposure to Lycopodium clavatum in condom manufacturers. Thorax 1993;48(7):774-775. 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 Clubmoss and Acetaminophen Together: Common Questions

Is it safe to take Clubmoss with Acetaminophen?
We do not list a known interaction between Clubmoss and Acetaminophen. 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 Clubmoss and Acetaminophen have any of the same side effects?
Yes — our sources link each of them separately to 2 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.
How was the Clubmoss and Acetaminophen combination checked?
Interactions in our licensed database are recorded against drug classes. Acetaminophen is filed under 8 classifications, and Clubmoss has documented interactions with 3 drug classes — none of Acetaminophen's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Clubmoss interact with any other medications?
Yes. Clubmoss has 219 documented drug interactions in our database — Acetaminophen is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Acetaminophen interact with any supplements?
Yes. Acetaminophen has documented interactions with 155 supplements in our database — Clubmoss is not one of them. The Acetaminophen 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 Acetaminophen and Clubmoss?

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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.