Salix alba · PhytoNexus

01 Identity and provenance

Accepted binomial: Salix alba
Common names: White Willow
Family (APG IV): Salicaceae
Part used: Bark
Verification tier: Tier 2 · Verified Clinical columns reviewed and a source is on record.
Reviewer note (2026 audit): USP Safety Review of Willow Bark: PubMed 31604354 | VERIFIED 2026 - synthetic analogue, application, interactions, side effects and references populated from retrieved primary/regulatory sources (see References). Interaction entries are labelled CLINICAL (case reports or trials in humans) vs THEORETICAL (in-vitro or animal only). Marketed-formulation column intentionally left blank. | HOST FACTOR

02 Constituent chemistry

Chemical class	Marker compound	Synthetic analogue in use
Phenolic glycosides	Salicin Bark	Aspirin, Salicylic acid (TRUE STRUCTURAL relationship - salicin is a natural prodrug metabolised to salicylate).

The analogue column is what makes the interaction reasoning tractable: where a constituent has a marketed structural counterpart, the counterpart's interaction profile is the starting hypothesis for the plant.

Looking up structures and physicochemical properties from PubChem…

03 Stated application

Reported activity: Low back pain, osteoarthritis, rheumatic complaints, headache and fever. Approved by German Commission E. Note the salicin dose alone is likely insufficient for analgesia - flavonoids and polyphenols contribute.
Reported adverse effects: CONTRAINDICATED in salicylate/aspirin hypersensitivity, G6PD deficiency (haemolytic anaemia), active peptic ulcer, third-trimester pregnancy, and in children (Reye syndrome concern). 240 mg salicin can yield approx. 113 mg salicylic acid. Less gastric mucosal damage than aspirin in comparative work.

04 Interaction matrix

Source column, verbatim: CLINICAL: anticoagulants, antiplatelets, other salicylates and NSAIDs - EMA monograph recommends an explicit warning on concomitant anticoagulant use. High tannin content may impair nutrient absorption on prolonged use.
Normalised onto 3 canonical drug classes below.

Curated from the reviewed source

Drug class	Severity	Mechanism type	Provenance	Expected effect
Anticoagulants (vitamin-K antagonists, DOACs) Haemostasis	3Major	PD-additive + PK-CYP2C9	curated A	INR destabilisation in either direction; ecchymosis, epistaxis, gum bleed…	why ▾
Chemistry of this pair. Salicylate esters hydrolyse to salicylic acid, giving irreversible platelet COX-1 acetylation equivalent to low-dose aspirin. Class mechanism. Coumarin-, salicylate- and coumestan-bearing botanicals add to vitamin-K-antagonist effect; several also compete for CYP2C9 and CYP3A4, raising S-warfarin exposure. Botanicals rich in vitamin K1 act in the opposite direction and blunt anticoagulation. Expected INR destabilisation in either direction; ecchymosis, epistaxis, gum bleeding, GI or intracranial haemorrhage. Management Do not start or stop the botanical without INR cover. Check INR at 3-5 days and again at 2 weeks. Document the product, batch and dose in the anticoagulation record. Onset rapid Evidence A - human data with a cited source Matched on “other salicylates” Find evidence for this pair Map this mechanism
Antiplatelet agents Haemostasis	3Major	PD-additive	curated A	Prolonged bleeding time, surgical and post-procedural bleeding, bruising,…	why ▾
Chemistry of this pair. Salicylate esters hydrolyse to salicylic acid, giving irreversible platelet COX-1 acetylation equivalent to low-dose aspirin. Class mechanism. Organosulfur compounds, gingerols, salicylates, ginkgolides and eugenol inhibit thromboxane A2 synthesis, platelet aggregation and PAF-mediated activation, duplicating the pharmacology of aspirin and P2Y12 blockers. Expected Prolonged bleeding time, surgical and post-procedural bleeding, bruising, haematuria. Management Stop the botanical 7-14 days before elective surgery or neuraxial anaesthesia. Record it on the pre-operative medicines list. Onset rapid Evidence A - human data with a cited source Matched on “antiplatelets” Find evidence for this pair Map this mechanism
NSAIDs Analgesia	3Major	PD-additive	curated A	Peptic ulceration, upper GI bleeding, acute kidney injury in volume-deple…	why ▾
Chemistry of this pair. Salicylate esters hydrolyse to salicylic acid, giving irreversible platelet COX-1 acetylation equivalent to low-dose aspirin. Class mechanism. Salicylate-, coumarin- and eugenol-bearing botanicals add both antiplatelet activity and direct gastric mucosal irritation to cyclo-oxygenase inhibition; several also reduce renal prostaglandin-dependent perfusion. Expected Peptic ulceration, upper GI bleeding, acute kidney injury in volume-depleted patients. Management Avoid in ulcer history. Add gastroprotection where the combination is unavoidable, and monitor renal function in the elderly. Onset rapid Evidence A - human data with a cited source Matched on “nsaids” Find evidence for this pair Map this mechanism

05 Hazard register

patient characteristic - G6PD deficiency, salicylate hypersensit

06 Confusable material

These entries could be mistaken for this one in trade, in the herbarium, or in a prescription. Powdered material is often indistinguishable, so the check is macroscopic, microscopic and chromatographic rather than nominal.

Veratrum album White Hellebore	Melanthiaceae	Shares the common name "white"
Epilobium parviflorum Small-flowered Willowherb	Onagraceae	Shares the common name "willow"

07 Mechanism map

Chemistry sorts to the left, pharmacology to the right. Dashed edges are predicted. Drag nodes, scroll to zoom, export at 3× for a figure.

species

chemical class

marker compound

drug class

expected effect

hazard

08 Open literature

Abstract-scoped query built from this binomial, its common names and its marker compounds, run live against Europe PMC, PubMed and OpenAlex, then ranked locally against an evidence hierarchy.

Checking openFDA spontaneous reports…

09 Isomechanistic neighbours

Species whose interaction profile overlaps this one, ranked by shared severity weight rather than by count — a shared contraindication counts for more than a shared minor signal. Practical use: these are the plants you should not stack with this one, because the mechanisms summate.

Species	Family	Shared classes	Jaccard
Trachyspermum ammi Ajwain	Apiaceae	3	0.75
Kaempferia galanga Chandramula	Zingiberaceae	3	0.75
Alpinia galanga Greater Galangal	Zingiberaceae	3	0.75
Gaultheria fragrantissima Wintergreen	Ericaceae	3	1.00
Filipendula ulmaria Meadowsweet	Rosaceae	3	1.00
Harpagophytum procumbens Devil's Claw	Pedaliaceae	3	0.75

10 References and notes

Source column: EMA/HMPC Assessment report on Salix cortex

EMA/HMPC Assessment report on Salix cortex

manual

BibTeX for all 1 records

@article{anon,
  title = {EMA/HMPC Assessment report on Salix cortex},
}

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