CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-22). The draft was written by AI, the existence of all 2 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 1086 · Search date 2026-07-22 · Methodology v0.6

Contractubex gel,
does it really help with Superior improvement of scar color, thickness, and pliability and prevention of hypertrophic scarring after surgery or trauma versus other topical treatments?

30-Second Summary
F
Evidence Grade F · 18 · Safety caution
The central claim of superiority over other topical treatments was repeatedly and directly contradicted and is rated F; some improvement versus no treatment remains a separate C subclaim
What the
research shows
The central claim that Contractubex is superior to other topical treatments is rated F because it has been repeatedly and directly contradicted. In a meta-analysis of 13 randomized trials, onion-extract gel improved investigator- and patient-rated scores versus no treatment, but it was not superior to other topical treatments such as petrolatum or silicone in investigator ratings, MD -0.16 (P=0.56), or patient ratings, MD 0.37 (P=0.39); the investigator-rated scar subgroup instead favored the comparators. In a 45-scar trial directly testing Contractubex, silicone gel and silicone sheeting were superior. Some improvement versus no treatment remains a separate C subclaim, but it does not support comparative superiority for color, thickness, pliability, or prevention.
What the
ads claim
Marketing turns anti-inflammatory mechanisms and before-and-after photographs into a claim that the product is better than standard topical care for color, thickness, pliability, and hypertrophic-scar prevention. The evidence requires separating possible improvement versus no treatment from superiority versus active alternatives.
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Useful facts when choosing a product

  • Contractubex combines onion extract, heparin, and allantoin in a topical scar gel, and country-specific labeling governs its authorized use and directions.
  • The studied scars included postsurgical, postburn, and hypertrophic scars; natural healing of a new scar is not equivalent to the response of a mature scar.
  • Onion-extract-only gels, onion-extract and silicone combinations, and Contractubex differ in composition and formulation, so results from one product cannot automatically be transferred to another.
  • Scar care begins after wound closure; infection, wound separation, a rapidly enlarging keloid, or a painful lesion warrants clinical assessment rather than self-treatment alone.
Gap Measurement · Verdict 1086 · F 18
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Yuan and colleagues synthesized 13 randomized trials and found higher total improvement scores with onion-extract gel than with no treatment, but no superiority over other topical treatments: investigator-rated MD -0.16 (P=0.56) and patient-rated MD 0.37 (P=0.39); the investigator-rated scar subgroup instead favored the comparators. Adverse effects increased versus both no treatment and other treatments, as did intolerance-related withdrawal. Karagoz and colleagues randomized 45 postburn hypertrophic scars, 15 each, to silicone gel, silicone sheeting, or Contractubex for six months. All groups improved from baseline, but both silicone groups were significantly better than Contractubex. Trials were generally small and varied by scar type, formulation, and scale, limiting precision even for comparisons with no treatment.

02

Why this is classified as F (18)

The central claim of superiority over other topical treatments was repeatedly contradicted by a meta-analysis and a direct comparative trial, giving F with 18 points. The meta-analysis found no superiority in investigator ratings, P=0.56, or patient ratings, P=0.39, the investigator-rated scar subgroup favored comparators, and an exact-combination trial favored silicone. Some improvement versus no treatment remains a separate C subclaim. Contact dermatitis, irritation, and the burden of prolonged application are separate safety issues.

Counterpoint. Someone choosing to try the gel should not replace standard wound care or sun protection and should compare its cost, irritation, and application burden with simple emollient or silicone care over the same period.

Rejudgment record. Cross-check applied — Applied F to the central comparative-superiority claim because a meta-analysis of 13 randomized trials found no superiority over other topical treatments, the investigator-rated scar subgroup favored comparators, and a direct exact-Contractubex comparison favored silicone; retained some improvement versus no treatment as a separate C subclaim

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Superior improvement of scar color, thickness, and pliability versus other topical treatmentsFThe meta-analysis found no superiority over other treatments and inferiority in the investigator-rated scar subgroup, while an exact-combination trial also favored silicone.
Superior prevention of hypertrophic scarring versus other topical treatmentsFThe comparative-superiority prevention claim was not demonstrated in heterogeneous small trials, and direct comparative evidence favored silicone.
Some improvement in scar appearance versus no treatmentCInvestigator and patient total-improvement scores were positive, but subjective scales, natural healing, and formulation heterogeneity limit confidence.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Study 1Systematic review and meta-analysis of randomized trials13Southwest Hospital youth-talent support; no product-related financial conflict reportedInvestigator- and patient-rated total scar improvement, adverse effects, and intolerance-related withdrawalTotal improvement scores were higher than with no treatment, but there was no superiority over other topical treatments in investigator ratings, MD -0.16 (P=0.56), or patient ratings, MD 0.37 (P=0.39), and the investigator-rated scar subgroup instead favored the comparators. Adverse effects increased versus other treatments, P=0.008, as did intolerance-related withdrawal, P=0.0002.Synthesis directly contradicting the central comparative-superiority claim and assessing safety
Study 2Three-arm randomized active-controlled trial15Funding source not stated in the PubMed recordSix-month Vancouver Scar ScaleAll three groups improved from baseline, but silicone gel and silicone sheeting were significantly superior to Contractubex.Direct comparative evidence for the exact combination
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Receipt — 2 References

All 2 cited sources were verified for existence at the original page (as of 2026-07-22).

Yuan X, Shen J, Chen L, Wang L, Yan Q, Zhang J. Onion extract gel is not better than other topical treatments in scar management: A meta-analysis from randomised controlled trails. Int Wound J. 2021;18(3):396-409. PMID: 33372412. PMCID: PMC8244018. DOI: 10.1111/iwj.13542.
checked
Karagoz H, Yuksel F, Ulkur E, Evinc R. Comparison of efficacy of silicone gel, silicone gel sheeting, and topical onion extract including heparin and allantoin for the treatment of postburn hypertrophic scars. Burns. 2009;35(8):1097-1103. PMID: 19766399. DOI: 10.1016/j.burns.2009.06.206.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-22 · Corrections: none

Cite this verdict

Contractubex gel x superior scar improvement and prevention versus other topical treatments Evidence Grade F card
[Chamgap] Contractubex gel x superior scar improvement and prevention versus other topical treatments — Evidence Grade F·18. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/skin-hair/contractubex-gel-scar-improvement-prevention-superiority/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.