Herb module
Liu Shu Pi
Willow BarkSalix alba
The cooling bark of the white willow, the botanical ancestor of aspirin, used to clear Heat and ease pain.
Liu Shu Pi is the bark of the white willow tree, a plant that has been used for centuries in Western herbal medicine and is known as the botanical precursor to aspirin. In Pain Release™ it joins classical Chinese herbs to clear Heat and ease pain. In Digestive Relief | Édafos™ it is used to cool inflammation and drain Damp-Heat from the Bladder.
Best functions
- Traditionally used to clear Heat and calm inflammation
- Used to ease aches and pain
- Helps drain Damp-Heat from the Bladder
- Used to encourage Yin and support Stomach Qi
- Traditionally used to help stop bleeding
Fascinating facts
- Willow bark is the botanical precursor to aspirin, one of the most commonly used drugs in the world.
- The bark contains salicin, which the body converts to salicylic acid. Studies suggest this calms the COX enzymes involved in inflammation and pain signaling.
- Willow bark and cramp bark both contain salicylates, natural compounds that are chemically related to aspirin.
- White willow is a tall tree that likes damp ground along rivers and streams. Its slender leaves have a silvery-white underside, which is where the name 'white willow' comes from.
In Traditional Chinese Medicine
Willow Bark is cool in nature, with a bitter flavor, and it is a Heat-clearing herb. Zoi's Digestive Relief | Édafos™ sheet says it enters the Kidney, Bladder, and Heart channels, and the Pain Release™ sheet lists the Liver and Kidney channels.
Biomedical deep dive
Liu Shu Pi Willow Bark
From the Zoi Medicinals fact sheets’ Biomedical Details, with lines from Noa’s herb notes marked “Noa’s notes”.
On the fact sheet
- Willow Bark (Salix alba) enters the LIV and KI meridians; clears Heat, alleviates pain, reduces inflammation, and stops bleeding. The botanical precursor to aspirin, used for centuries in western herbal medicine. Pain Release · sheet
- Liu Shu Pi (Willow Bark, Salix alba) is cool and enters the KI, BL and HT meridian; clears Heat and inflammation, drains DampHeat in the Bladder, encourages Yin and supports Stomach Qi. Digestive Relief | Édafos · sheet
Key active constituents
- Salicylates, which are chemically and pharmacologically related to aspirin (Pain Release sheet).
- The Édafos sheet notes that aspirin was derived from white willow bark.
Pharmacology and mechanisms
- The Pain Release sheet lists willow bark among the formula's analgesic (pain-relieving) herbs.
- It reduces prostaglandin production (prostaglandins are pain and inflammation messengers) by inhibiting COX enzymes.
- The Pain Release sheet credits it, with Dan Shen, Qin Jiao, Bai Shao, Du Huo and Gui Zhi, with modulating NF-κB (a master switch for inflammation).
- Salicin is converted in the body to salicylic acid; it is analgesic and anti-inflammatory through COX-1 and COX-2 inhibition. Noa’s notes
- Meta-analysis support for low back pain and osteoarthritis. Noa’s notes
What the research says
- Willow bark and aspirin relieve pain through partly different mechanisms (Vlachojannis et al., Phytother Res 2011).
- A review covers white willow bark's efficacy and safety (Shara and Stohs, Phytother Res 2015).
- In a meta-analysis of randomized trials with 329 arthritis patients, willow bark was associated with significant pain reduction (Lin et al., Life 2023).
Safety, interactions and cautions
- Every Zoi fact sheet: do not use if pregnant or breastfeeding unless directed by your health care practitioner.
- The Pain Release fact sheet cautions anyone allergic to aspirin or salicylates, because the formula contains willow bark and crampbark.
- The Pain Release fact sheet cautions using it with anticoagulant or antiplatelet medicines (such as warfarin, aspirin or clopidogrel), because several of its herbs promote circulation and may add to their effect.
- Caution with aspirin allergy. Noa’s notes
- Caution with anticoagulants (blood thinners). Noa’s notes
- Caution in pregnancy. Noa’s notes
In these Zoi formulas
- Pain Release (#10 on the fact sheet)
- Digestive Relief | Édafos (#10 on the fact sheet)
