Basket Willow, Bay Willow, Black Willow, Black Willowbark, Black
Willow Extract, European Willow Bark.
Salix alba; other Salix species.
People Use This For:
Willow bark is used for headache, pain, muscle pain,
osteoarthritis, painful periods, gouty arthritis, ankylosing
spondylitis, rheumatoid arthritis, and gout. It is also used for
fever, common cold, and influenza.
No concerns regarding safety when used orally and appropriately,
short-term.19,20,21,22,23 Willow bark has been used
safely for up to 13 weeks in one study.23
Children: Possibly Unsafe.24 Although Reye's syndrome
has not been reported, the salicin constituent in willow bark is
similar to aspirin and might pose the same risk.
Pregnancy and Breastfeeding: Consult a Medical Herbalist.
Back pain. There's some evidence that a willow bark extract
providing 120-240mg of the salicin constituent daily can reduce
low back pain in some patients. The higher concentration of 240mg
salicin is more effective than 120mg of salicin. It can take up
to 1 week for significant relief.19 Some research
suggests salicin 240mg daily is as effective as rofecoxib (Vioxx)
for low back pain.22
INSUFFICIENT RELIABLE EVIDENCE to RATE
Osteoarthritis. Clinical research on willow bark extract for
osteoarthritis is conflicting. Some research suggests it has a
moderate analgesic effect on osteoarthritis, while other research
shows it is similar to placebo and inferior to diclofenac
Rheumatoid arthritis (RA). Preliminary clinical research suggests
that willow bark extract is not effective for rheumatoid
More evidence is needed to rate willow bark for these uses.
Mechanism of Action:
Willow bark is the bark of salix tree species such as the white
willow. Willow bark constituents include flavonoids, tannins, and
salicylates. The active constituent of willow bark is thought to
be salicin. Salicin is metabolized to salicyl alcohol and then to
salicylic acid. From there, metabolism is the same as
An ethanolic extract of willow bark seems to inhibit
cyclooxygenase (COX)-2 mediated prostaglandin release, but it
doesn't seem to directly affect COX-1 or COX-2 activity.
Constituents of willow bark other than salicin may have
lipoxygenase-inhibiting and antioxidant effects that could
contribute to its analgesic effect.19,26 They also
might prevent prostaglandin and cytokine release.26
Some research suggests that extended treatment with willow bark
may be necessary for a therapeutic effect.27,28
Preliminary research suggests that willow bark extracts have
analgesic, anti-inflammatory, and antipyretic
effects.26 Willow bark inhibits platelet aggregation,
but to a lesser degree than aspirin.29
Bioavailability of willow bark may be lower due to manufacturing
processes. A dose of 240mg of salicin is equivalent to 87mg of
Willow bark extract can cause gastrointestinal adverse effects,
but these appear to be less frequent than those caused by
NSAIDs.20,21 Willow bark may cause itching and rash,
as well as serious allergic reactions, including anaphylaxis, in
people who are allergic to aspirin.30,20,21
Salicylates can inhibit prostaglandins, which can reduce renal
blood flow.31 Salicin can cause renal papillary
necrosis.32 The risk for toxicity is greater with high
acute doses or chronic use.31
Interactions with Herbs & Supplements:
Anticoagulant/Antiplatelet Herbs and Supplements: Concomitant use
of herbs that have antiplatelet/anticoagulant effects could
theoretically increase the risk of bleeding in some
people.29 These herbs include clove, danshen, garlic,
ginger, ginkgo, ginseng, meadowsweet, red clover, and others.
Salicylate-Containing Herbs: Theoretically, concomitant use may
potentiate salicylate effects and adverse effects.25
Salicylate-containing herbs include aspen bark, black haw,
poplar, and meadowsweet.
Interactions with Drugs:
Warfarin: Absolute contraindication.
Aspirin: Willow bark contains salicin, a plant salicylate.
Theoretically, willow bark might have an additive effect with
other salicylate-containing drugs such as aspirin.25
Choline Magnesium Trisalicylate (Trilisate): Interaction Rating =
Moderate Be cautious with this combination. Severity = Moderate.
Occurrence = Probable. Willow bark contains salicin, a plant
salicylate. Theoretically, willow bark might have an additive
effect with other salicylate-containing drugs such as choline
Salsalate (Disalcid): Interaction Rating = Moderate Be cautious
with this combination. Severity = Moderate. Occurrence =
Willow bark contains salicin, a plant salicylate. Theoretically,
willow bark might have an additive effect with other
salicylate-containing drugs such as salsalate.25
Interactions with Foods:
Interactions with Lab Tests:
Creatinine: Theoretically, salicin could cause a rise in serum
creatinine without affecting renal function. Salicylates can
cause a rise in serum creatine without a change in glomerular
filtration rate (GFR). This is thought to be due to changes in
plasma protein binding caused by salicylates or competitive
inhibition of tubular secretion of creatinine by
Interactions with Diseases or Conditions:
Kidney Dysfunction: Theoretically, salicin might reduce renal
blood flow.31 Chronic use of high doses might
contribute to renal failure in predisposed people.32
Avoid use in people with compromised renal function.
Salicylate Precautions: Avoid or use cautiously in individuals
with aspirin hypersensitivity, asthma, active peptic ulcer
disease, diabetes, gout, hemophilia, hypoprothrombinemia, kidney
or liver disease. Willow bark may cause serious allergic
reactions, including anaphylaxis, in people who are allergic to
Surgery: discontinue willow bark at least 2 weeks before elective
Dr Clare’s Blend: 700mgs/day
Oral: For back pain, willow bark extract providing 120-240mg
salicin has been used. The higher 240mg dose might be more
Specific References: WHITE WILLOW
19. 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.
20. 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.
21. 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.
22. 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.
23. Coffey CS, Steiner D, Baker BA, Allison DB. A
randomized double-blind placebo-controlled clinical trial of a
product containing ephedrine, caffeine, and other ingredients
from herbal sources for treatment of overweight and obesity in
the absence of lifestyle treatment. Int J Obes Relat Metab Disord
24. Food and Drug Administration, HHS. Labeling for oral
and rectal over-the-counter drug products containing aspirin and
nonaspirin salicylates; Reye's Syndrome warning. Final rule. Fed
25. 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.
26. Fiebich BL, Chrubasik S. Effects of an ethanolic salix
extract on the release of selected inflammatory mediators in
vitro. Phytomedicine 2004;11:135-8.
27. Wagner I, Greim C, Laufer S, et al. Influence of willow
bark extract on cyclooxygenase activity and on tumor necrosis
factor alpha or interleukin 1 beta release in vitro and ex vivo.
Clin Pharmacol Ther 2003;73:272-14.
28. Fiebich BL, Appel K. Anti-inflammatory effects of
willow bark extract. Clin Pharmacol Ther 2003;74:96.
29. Krivoy N, Pavlotzky E, Chrubasik S, et al. Effect of
salicis cortex extract on human platelet aggregation. Planta Med
30. Boullata JI, McDonnell PJ, Oliva CD. Anaphylactic
reaction to a dietary supplement containing willow bark. Ann
31. D'Agati V. Does aspirin cause acute or chronic renal
failure in experimental animals and in humans? Am J Kidney Dis
32. Schwarz A. Beethoven's renal disease based on his
autopsy: a case of papillary necrosis. Am J Kidney Dis
33. Andreev E, Koopman M, Arisz L. A rise in plasma
creatinine that is not a sign of renal failure: which drugs can
be responsible? J Intern Med 1999;246:247-52.