Drug & supplement interaction

Willow Bark + Botulinum Toxin Type A

Botulinum Toxin Type A brand name: Botox.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Willow Bark and Botulinum Toxin Type A 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

Willow Bark and Botulinum Toxin Type A

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 Botulinum Toxin Type A and Willow Bark 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.

Willow Bark safety at a glance

Willow Bark overall Use caution Generally tolerated short-term by healthy adults, but it acts like aspirin and is not safe for everyone.
Pregnancy Avoid Avoid during pregnancy because its aspirin-like action may pose risks, especially later in pregnancy.
Breastfeeding Possibly Unsafe When used orally. Willow bark contains salicylates which are excreted in breast milk and have been linked to adverse effects in breast-fed infants. 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 Botulinum Toxin Type A and Willow Bark? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
Keep it in perspective

Willow Bark Does Interact With Other Medications

Willow Bark has 127 moderate known drug interactions in our database — Botulinum Toxin Type A 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 Willow Bark

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

What to actually watch for

What Willow Bark Itself Has Been Linked To

This is not an interaction — nothing below involves Botulinum Toxin Type A. It is the side-effect record for Willow Bark on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Willow Bark, this list is the first place to look. 2 entries are worth acting on rather than waiting out — marked below.

  • Bleeding in the gut / Bleeding or bruising Worth acting on Additional detail

    “Orally, willow bark extract can cause gastrointestinal adverse effects, but these appear to be less frequent than those caused by NSAIDs. Examples include diarrhea, heartburn, vomiting, and dyspepsia. In a case report of a child, severe gastrointestinal bleeding occurred following use of a specific syrup (FreddoBaby), which contained ribwort plantain, licorice, willow bark, black elder, meadowsweet, and propolis.”

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

    5 sources cited
    1. 12474. Schmid B, Ludtke R, Selbmann HK, et al. Efficacy and tolerability of a standardized willow bark extract in patients with osteoarthritis: randomized placebo-controlled, double blind clinical trial. Phytother Res 2001;15:344-50. PubMed
    2. 12475. Biegert C, Wagner I, Ludtke R, et al. Efficacy and safety of willow bark extract in the treatment of osteoarthritis and rheumatoid arthritis: results of 2 randomized double-blind controlled trials. J Rheumatol 2004;31:2121-30.
    3. 12804. Chrubasik S, Kunzel O, Model A, et al. Treatment of low back pain with a herbal or synthetic anti-rheumatic: a randomized controlled study. Willow bark extract for low back pain. Rheumatology (Oxford) 2001;40:1388-93. PubMed
    4. 86459. Chrubasik, S., Kunzel, O., Black, A., Conradt, C., and Kerschbaumer, F. Potential economic impact of using a proprietary willow bark extract in outpatient treatment of low back pain: an open non-randomized study. Phytomedicine 2001;8(4):241-251. PubMed
    5. 86477. <p>Moro PA, Flacco V, Cassetti F, Clementi V, Colombo ML, Chiesa GM, Menniti-Ippolito F, Raschetti R, Santuccio C. Hypovolemic shock due to severe gastrointestinal bleeding in a child taking an herbal syrup. Ann Ist Super Sanita. 2011;47(3):278-83.</p>
  • Kidney problems / A severe allergic reaction / An allergic reaction Worth acting on Additional detail

    Recorded for Willow Bark in the same Natural Medicines adverse-effect record shown under Bleeding in the gut / Bleeding or bruising above.

  • Heartburn / Stomach upset / Diarrhea Additional detail

    Recorded for Willow Bark in the same Natural Medicines adverse-effect record shown under Bleeding in the gut / Bleeding or bruising above.

  • Itching Additional detail

    “Orally, willow bark may cause itching and rash in some people due to allergy.”

    Willow Bark · Natural Medicines adverse-effect record, reported in allergic rhinitis (hay fever).

    5 sources cited
    1. 6456. Chrubasik S, Eisenberg E, Balan E, et al. Treatment of low back pain exacerbations with willow bark extract: a randomized double-blind study. Am J Med 2000;109:9-14. PubMed
    2. 12474. Schmid B, Ludtke R, Selbmann HK, et al. Efficacy and tolerability of a standardized willow bark extract in patients with osteoarthritis: randomized placebo-controlled, double blind clinical trial. Phytother Res 2001;15:344-50. PubMed
    3. 12475. Biegert C, Wagner I, Ludtke R, et al. Efficacy and safety of willow bark extract in the treatment of osteoarthritis and rheumatoid arthritis: results of 2 randomized double-blind controlled trials. J Rheumatol 2004;31:2121-30.
    4. 12804. Chrubasik S, Kunzel O, Model A, et al. Treatment of low back pain with a herbal or synthetic anti-rheumatic: a randomized controlled study. Willow bark extract for low back pain. Rheumatology (Oxford) 2001;40:1388-93. PubMed
    5. 86459. Chrubasik, S., Kunzel, O., Black, A., Conradt, C., and Kerschbaumer, F. Potential economic impact of using a proprietary willow bark extract in outpatient treatment of low back pain: an open non-randomized study. Phytomedicine 2001;8(4):241-251. PubMed
  • Dizziness Additional detail

    “Orally, willow bark may cause headache and dizziness. In a clinical trial evaluating a combination product containing willow bark, black cohosh, sarsaparilla, poplar bark, and guaiac wood (Reumalex), severe headaches occurred.”

    Willow Bark · Natural Medicines adverse-effect record, reported in cluster headache.

    2 sources cited
    1. 12804. Chrubasik S, Kunzel O, Model A, et al. Treatment of low back pain with a herbal or synthetic anti-rheumatic: a randomized controlled study. Willow bark extract for low back pain. Rheumatology (Oxford) 2001;40:1388-93. PubMed
    2. 35946. Mills SY, Jacoby RK, Chacksfield M, Willoughby M. Effect of a proprietary herbal medicine on the relief of chronic arthritic pain: a double-blind study. Br J Rheumatol 1996;35:874-8. PubMed

Showing the 10 most notable of 13 recorded effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

Everything above comes from the Natural Medicines adverse-effect record for Willow Bark — expand a row for the licensed statement it rests on. We haven’t matched Botulinum Toxin Type A to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Botulinum Toxin Type A.

Special populations

Willow Bark in Pregnancy & Breastfeeding

Lactation Possibly Unsafe

When used orally. Willow bark contains salicylates which are excreted in breast milk and have been linked to adverse effects in breast-fed infants.

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

Overlapping uses

What Botulinum Toxin Type A Is Prescribed For, and What Willow Bark Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Botulinum Toxin Type A is a prescription medicine with approved uses on its FDA label. Willow Bark is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Botulinum Toxin Type A is prescribed for: Botox is approved to treat a wide range of conditions in adults and some children. These include overactive bladder (OAB) with urge incontinence, urinary incontinence caused by nerve-related bladder overactivity (in adults and in children aged 5 and older), prevention of headaches in adults with chronic migraine (15 or more headache days per month), muscle stiffness (spasticity) in patients aged 2 and older, cervical dystonia (abnormal head position and neck pain), severe underarm sweating (primary axillary hyperhidrosis) when topical treatments haven't worked, eyelid spasms (blepharospasm) in patients aged 12 and older, and crossed eyes (strabismus) in patients aged 12 and older. BOTOX Cosmetic is a separate product containing the same active ingredient but with its own approved cosmetic uses. Both products are given by injection and are not interchangeable with other botulinum toxin products.

Read the rest of what Botulinum Toxin Type A is prescribed for

Botox has not been shown to work for episodic migraine (14 or fewer headache days per month), and its safety for excessive sweating in body areas other than the underarms has not been established.

Willow Bark has been studied for:

  • Headache studied, not established Willow Bark has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Willow Bark for headache

    Although there has been interest in using oral willow bark for headache, there is insufficient reliable information about the clinical effects of willow bark for this purpose.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Botulinum Toxin Type A on your own; if you are taking Willow Bark for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Willow Bark or Botulinum Toxin Type A

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Willow Bark or Botulinum Toxin Type A, 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.

One more smart check

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

We hold 43 real supplement products containing Willow Bark, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Willow Bark. Even though Willow Bark itself has no known interaction with Botulinum Toxin Type A, 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 Willow Bark and Botulinum Toxin Type A 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 Willow Bark
Steady interest

#1,009 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Botulinum Toxin Type A
Top half

#1,048 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 Willow Bark reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Willow Bark and Botulinum Toxin Type A records this page draws on were last updated July 11, 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 Willow Bark

What is Willow Bark?

  • Low back pain
  • Osteoarthritis joint pain
  • Headache
  • Fever
  • General aches and inflammation

Willow bark is a traditional plant remedy that contains salicin, a compound related to aspirin, and is most often used for pain and inflammation. Some evidence suggests it may modestly help low back pain and joint pain, but the research is limited and the right dose is not well standardized. Because it acts like aspirin, people with aspirin allergies, bleeding problems, or who are pregnant should be cautious and talk to a pharmacist or doctor first.

Salix alba · Salicaceae · Bark · Capsules, tablets, dried bark for tea, liquid extracts, standardized extracts

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

Willow Bark: dosing

There is no single official dose for willow bark. Products vary widely, and many are standardized to a certain amount of salicin, which is the part researchers usually measure.Because strength differs from brand to brand, the best approach is to follow the directions on the product label and not exceed them. They can help you decide whether willow bark is appropriate and how much is reasonable for you.

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

Read the full Willow Bark monograph & all interactions
Medication

About OnabotulinumtoxinA Injection

What Is OnabotulinumtoxinA Injection Used For?

Brand name: Botox

Botox is approved to treat a wide range of conditions in adults and some children. These include overactive bladder (OAB) with urge incontinence, urinary incontinence caused by nerve-related bladder overactivity (in adults and in children aged 5 and older), prevention of headaches in adults with chronic migraine (15 or more headache days per month), muscle stiffness (spasticity) in patients aged 2 and older, cervical dystonia (abnormal head position and neck pain), severe underarm sweating (primary axillary hyperhidrosis) when topical treatments haven't worked, eyelid spasms (blepharospasm) in patients aged 12 and older, and crossed eyes (strabismus) in patients aged 12 and older.

BOTOX Cosmetic is a separate product containing the same active ingredient but with its own approved cosmetic uses. Both products are given by injection and are not interchangeable with other botulinum toxin products. Botox has not been shown to work for episodic migraine (14 or fewer headache days per month), and its safety for excessive sweating in body areas other than the underarms has not been established.

Most-Reported Side Effects for Botulinum Toxin Type A

From FAERS, the FDA’s public side-effect reporting system (12,344 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Headache 1,596 reports
Drug intolerance 1,333 reports
Nausea 1,266 reports
Migraine 1,176 reports
Dizziness 1,126 reports
See full OnabotulinumtoxinA Injection drug information
Keep checking

Other Drugs & Willow Bark

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

0Major
127Moderate
0Minor
2,702No known interaction
Moderate

127 interactions

Showing 60 of 127 moderate interactions — see all 127 on the Willow Bark page.

No interaction 2,702 drugs checked — show the list
Evidence & sources

Willow Bark References

The 12 references that drive our Willow Bark 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. Chrubasik S, Eisenberg E, Balan E, et al. Treatment of low back pain exacerbations with willow bark extract: a randomized double-blind study. Am J Med 2000;109:9-14. PubMed
  2. Schmid B, Ludtke R, Selbmann HK, et al. Efficacy and tolerability of a standardized willow bark extract in patients with osteoarthritis: randomized placebo-controlled, double blind clinical trial. Phytother Res 2001;15:344-50. PubMed
  3. Biegert C, Wagner I, Ludtke R, et al. Efficacy and safety of willow bark extract in the treatment of osteoarthritis and rheumatoid arthritis: results of 2 randomized double-blind controlled trials. J Rheumatol 2004;31:2121-30.
  4. Unsworth J, d'Assis-Fonseca A, Beswick DT, Blake DR. Serum salicylate levels in a breast fed infant. Ann Rheum Dis 1987;46:638-9. PubMed
  5. Clark JH, Wilson WG. A 16-day-old breast-fed infant with metabolic acidosis caused by salicylate. Clin Pediatr (Phila) 1981;20:53-4. PubMed
  6. Chrubasik S, Kunzel O, Model A, et al. Treatment of low back pain with a herbal or synthetic anti-rheumatic: a randomized controlled study. Willow bark extract for low back pain. Rheumatology (Oxford) 2001;40:1388-93. PubMed
  7. Schmid B, Kotter I, Heide L. Pharmacokinetics of salicin after oral administration of a standardised willow bark extract. Eur J Clin Pharmacol. 2001;57:387-91. PubMed
  8. Krivoy N, Pavlotzky E, Chrubasik S, et al. Effect of salicis cortex extract on human platelet aggregation. Planta Med 2001;67:209-12. PubMed
  9. Mills SY, Jacoby RK, Chacksfield M, Willoughby M. Effect of a proprietary herbal medicine on the relief of chronic arthritic pain: a double-blind study. Br J Rheumatol 1996;35:874-8. PubMed
  10. Chrubasik, S., Kunzel, O., Black, A., Conradt, C., and Kerschbaumer, F. Potential economic impact of using a proprietary willow bark extract in outpatient treatment of low back pain: an open non-randomized study. Phytomedicine 2001;8(4):241-251. PubMed
  11. <p>Moro PA, Flacco V, Cassetti F, Clementi V, Colombo ML, Chiesa GM, Menniti-Ippolito F, Raschetti R, Santuccio C. Hypovolemic shock due to severe gastrointestinal bleeding in a child taking an herbal syrup. Ann Ist Super Sanita. 2011;47(3):278-83.</p>
  12. Sweeney, K. R., Chapron, D. J., Brandt, J. L., Gomolin, I. H., Feig, P. U., and Kramer, P. A. Toxic interaction between acetazolamide and salicylate: case reports and a pharmacokinetic explanation. Clin Pharmacol Ther 1986;40(5):518-524.

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 Willow Bark and Botulinum Toxin Type A Together: Common Questions

Is it safe to take Willow Bark with Botulinum Toxin Type A?
We do not list a known interaction between Willow Bark and Botulinum Toxin Type A. 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.
Are Willow Bark and Botulinum Toxin Type A used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Willow Bark in each. That is a conversation for your prescriber, especially if Botulinum Toxin Type A is being adjusted to a target.
Does Willow Bark interact with any other medications?
Yes. Willow Bark has 127 documented drug interactions in our database — Botulinum Toxin Type A is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

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

Still Have a Question About Botulinum Toxin Type A and Willow Bark?

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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.