Evidence Explorer · MS-N306 · Botanicals · Supportive care · Appraised 11 November 2026
One small double-blind trial found that 1% silymarin gel delayed and reduced acute radiodermatitis during postmastectomy breast radiotherapy.
Evidence at a glance
- Evidence label: Promising small randomized trial; confirmation needed
- Benefit: Median dermatitis grades were lower from weeks 3–5 and onset/progression was delayed.
- Certainty: Low: only 40 participants, single study, short follow-up and no robust evidence for severe grade 3 dermatitis.
- Risk: Topical irritation or allergy is possible; oral milk-thistle interaction evidence does not automatically apply to a skin gel.
- Goal: Prevention of acute radiation dermatitis; not tumor control.
What was studied
Design: Forty postmastectomy breast-cancer patients were randomized double-blind to 1% silymarin gel or placebo, applied once daily to chest-wall skin from the first radiotherapy day for five weeks.
Results: Median NCI-CTCAE and RTOG dermatitis scores were significantly lower with silymarin from the end of week 3 through week 5, and development/progression was delayed. Both groups’ scores increased during radiotherapy.
Context: A 2025 network meta-analysis ranked silymarin highly for grade 2 or worse dermatitis (RR 0.05, 95% CI 0.00–0.87) but found no intervention superior for grade 3 dermatitis; the estimate rests heavily on limited small-trial evidence.
What this evidence cannot establish
This trial does not prove prevention of severe skin injury, benefit in other radiation fields, or equivalence of retail milk-thistle creams.
A reduction in dermatitis severity does not indicate better cancer control.
Safety and practical context
Do not apply an unapproved product to broken skin or immediately before treatment without the radiation team’s instructions; residue can affect skin care protocols.
Stop and seek review for worsening redness, blistering, drainage or signs of allergy or infection.
Questions for the care team
- Does the radiation service permit this exact gel and application timing?
- Is the skin intact, and how will dermatitis be graded?
- What standard moisturizers or dressings should continue?
Sources and identifiers
- Randomized double-blind trial (PMID 30479044)
- DOI 10.1002/ptr.6231
- 2025 network meta-analysis (PMID 41199840)
Funding and conflicts: The abstract did not report funding or conflicts; full-text details were not independently verified.
Source access: Original reports, abstracts/full text where available, registries and authoritative safety sources checked 11 November 2026. The primary trial was appraised from its abstract, so unreported numeric details were not inferred.
This educational evidence record is not a personal treatment recommendation. Symptom or toxicity findings do not establish tumor response, delayed recurrence or longer survival; laboratory and animal findings are not proof of clinical benefit.
