NutriDex

The Supplement Research Compendium
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White Willow Bark

Salix alba

Aspirin's botanical ancestor, used for back and joint pain.

Moderate evidence ✨Joint & Skin

✚ Updated · How we grade evidence

Evidence tier
Moderate
Research weight
Citations
7 verified / 7
Classification
Joint & Skin
❝
What the evidence says. Graded moderate: good short-term RCTs and a Cochrane review show real relief of low-back-pain flares at 240 mg salicin, but the largest, best-controlled osteoarthritis trial was null and the pooled arthritis effect is small with very-low GRADE certainty. (Moderate evidence: Several controlled trials; effects real but modest or context-dependent.)

What is White Willow Bark?

White Willow Bark (Salix alba) is a joint and skin supplement used for ease low-back pain flares. NutriDex grades the human evidence as Moderate. White willow bark is the plant from which salicin — the precursor of aspirin's active ingredient — is derived. Its best evidence is for acute flares of chronic low-back pain: in a 210-patient RCT, 39% of people on 240 mg salicin/day were pain-free in the final week versus 6% on placebo, and a Cochrane review rated this 'moderate' evidence, with one trial showing rough parity to rofecoxib. For osteoarthritis the picture is mixed: a small 2-week trial found a modest WOMAC pain drop (14% vs placebo), but the larger, more rigorous 2004 trial (240 mg salicin vs diclofenac vs placebo) found no benefit over placebo while diclofenac clearly worked. A 2023 meta-analysis of arthritis trials found only a small pooled effect (SMD −0.31) rated very-low certainty. Useful and generally well tolerated, but milder and less consistent than standard analgesics.

Purported Benefits

✓Ease low-back pain flares
✓Relieve osteoarthritis pain
✓Anti-inflammatory support
✓Aspirin-like pain relief

Evidence by outcome

The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.

OutcomeEvidenceEffectStudies
Ease acute low-back pain flares210-patient RCT showed 39% pain-free on 240 mg salicin vs 6% placebo; Cochrane rated moderate. Moderate ↑ benefit · moderate 2
Relieve osteoarthritis painSmall trial positive but larger rigorous RCT found no benefit; meta-analysis SMD -0.31, very-low certainty. Mixed ↔ mixed · small 3
Match standard therapy with better tolerabilityObservational cohort only; willow roughly matched usual care on WOMAC, no randomization. Preliminary ↑ benefit 1

Dosing & Compounds

Typical Dose
Standardized extract delivering 120–240 mg salicin/day; the 240 mg dose carries most of the positive trial evidence.
Active Compounds
SalicinSalicylates (salicortin, tremulacin)Polyphenols & flavonoids

Safety & Cautions

Willow bark acts like a mild aspirin: it can cause stomach upset, GI bleeding and allergic reactions, and is dangerous in people with aspirin/salicylate allergy (anaphylaxis has been reported). It should not be given to children or teens with viral illness (Reye's syndrome risk) and is best avoided in pregnancy, peptic ulcer, asthma, and kidney or liver disease. It can add to the bleeding risk of warfarin and other anticoagulants/antiplatelets and may interact with other NSAIDs, methotrexate and some blood-pressure or diabetes medications — talk to a clinician before combining. Educational only — always check with your doctor or pharmacist before combining White Willow Bark with any medicine.

White Willow Bark drug interactions

Known or theoretical interactions between White Willow Bark and common medications — educational, not exhaustive. Always check with your doctor or pharmacist before combining White Willow Bark with any medicine.

Avoid
Aspirin / NSAID allergy
Avoid white willow if you are allergic to aspirin or NSAIDs; it can trigger the same reaction.
Willow's salicin yields salicylic acid, which can provoke salicylate/NSAID hypersensitivity (asthma, hives). MedlinePlus — Aspirin (allergy warning)
Caution
Blood thinners (warfarin, DOACs)
White willow's salicylates may add to blood thinners and raise bleeding risk.
Salicin-derived salicylic acid has antiplatelet activity that compounds anticoagulation. NCCIH — Herbs at a Glance (willow bark)

Key Studies

Meta-analysis Shara 2023 ✓ Full text
Meta-analysis (6 RCTs, 329 arthritis patients): small pain benefit vs placebo (SMD −0.31, 95% CI −0.53 to −0.08); very-low GRADE certainty.
Systematic review Gagnier 2007 (Cochrane) ✓ PubMed
Moderate evidence that 120–240 mg salicin/day improves short-term low-back pain; one trial showed rough equivalence to rofecoxib.
RCT Chrubasik 2000 ✓ PubMed
RCT (n=210, back-pain flare): 39% pain-free on 240 mg salicin vs 21% on 120 mg vs 6% placebo in the final week.
RCT Biegert 2004 ✓ PubMed
RCT: 240 mg salicin showed no benefit over placebo for OA (or RA); diclofenac cut WOMAC pain 47% vs placebo's 10%.
RCT Schmid 2001 ✓ PubMed
RCT (n=78, knee/hip OA, 2 wk): 240 mg salicin reduced WOMAC pain 14% vs a 2% rise on placebo (p=0.047).
Cohort Beer 2008 ✓ PubMed
Observational cohort (n≈131, gon-/coxarthrosis, 6 wk): willow bark roughly matched standard therapy on WOMAC with better tolerability.
Cohort Chrubasik 2001 ✓ PubMed
Open outpatient study: willow bark extract for low-back pain reduced analgesic use and projected lower treatment costs vs usual care.
7 sources cited · 7 verified Search all studies on PubMed ↗

Common questions about White Willow Bark

What is White Willow Bark used for?

White Willow Bark is most often taken for Ease low-back pain flares, Relieve osteoarthritis pain, Anti-inflammatory support, Aspirin-like pain relief. Aspirin's botanical ancestor, used for back and joint pain.

Does White Willow Bark work — what does the evidence say?

Moderate evidence. Several controlled trials; effects real but modest or context-dependent. White willow bark is the plant from which salicin — the precursor of aspirin's active ingredient — is derived. Its best evidence is for acute flares of chronic low-back pain: in a 210-patient RCT, 39% of people on 240 mg salicin/day were pain-free in the final week versus 6% on placebo, and a Cochrane review rated this 'moderate' evidence, with one trial showing rough parity to rofecoxib. For osteoarthritis the picture is mixed: a small 2-week trial found a modest WOMAC pain drop (14% vs placebo), but the larger, more rigorous 2004 trial (240 mg salicin vs diclofenac vs placebo) found no benefit over placebo while diclofenac clearly worked. A 2023 meta-analysis of arthritis trials found only a small pooled effect (SMD −0.31) rated very-low certainty. Useful and generally well tolerated, but milder and less consistent than standard analgesics.

What is the typical dose of White Willow Bark?

Standardized extract delivering 120–240 mg salicin/day; the 240 mg dose carries most of the positive trial evidence.

Is White Willow Bark safe? Any cautions or side effects?

Willow bark acts like a mild aspirin: it can cause stomach upset, GI bleeding and allergic reactions, and is dangerous in people with aspirin/salicylate allergy (anaphylaxis has been reported). It should not be given to children or teens with viral illness (Reye's syndrome risk) and is best avoided in pregnancy, peptic ulcer, asthma, and kidney or liver disease. It can add to the bleeding risk of warfarin and other anticoagulants/antiplatelets and may interact with other NSAIDs, methotrexate and some blood-pressure or diabetes medications — talk to a clinician before combining.

How many studies support White Willow Bark?

NutriDex cites 7 sources for White Willow Bark, graded "Moderate".

Does White Willow Bark interact with any medications?

Yes — known or theoretical interactions include: Antiplatelet drugs (aspirin, clopidogrel) (avoid), Blood thinners (warfarin, DOACs) (caution). This is educational and not exhaustive; always check with your doctor or pharmacist before combining White Willow Bark with any medicine.

Cite this page
APA

Peh, D. (2026). White Willow Bark (Salix alba): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 26 Jun 2026, from https://nutridex.info/s/white-willow

BibTeX
@misc{nutridex_white_willow,
  author       = {Peh, Daryl},
  title        = {White Willow Bark (Salix alba): Benefits, Dosage, Side Effects \& Evidence},
  year         = {2026},
  howpublished = {NutriDex --- The Supplement Research Compendium},
  url          = {https://nutridex.info/s/white-willow},
  note         = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-06-26}
}

For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.

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