Insulin for Keloid Treatment
Intralesional insulin shows promising efficacy for keloid treatment and may be superior to botulinum toxin-A, though it remains an emerging therapy without established guidelines or FDA approval for this indication.
Current Evidence for Insulin in Keloids
The most recent and highest quality direct evidence comes from a 2025 randomized controlled trial comparing intralesional insulin to botulinum toxin-A (BTX-A) and corticosteroids for keloid treatment 1. This study demonstrated:
- 66.6% volume reduction with insulin versus 25.3% with BTX-A and 75% with corticosteroids
- Insulin was statistically superior to BTX-A in improving pigmentation, reducing thickness, and providing symptom relief
- Insulin performed comparably to corticosteroids, the current standard of care
A 2026 network meta-analysis examining 51 studies with 3,234 participants found that while combination therapies (5-FU + corticosteroids + YAG laser) ranked highest overall, insulin showed potential as an emerging agent but requires further standardized research 2.
Clinical Context and Limitations
Important Caveats
Insulin is NOT FDA-approved for keloid treatment. The FDA labeling for insulin products (Levemir) only addresses diabetes management and specifically warns about injection site reactions including lipodystrophy, which ironically involves abnormal subcutaneous tissue changes 3.
The available guidelines focus exclusively on keloid prevention rather than treatment. The 2017 Pediatrics guideline emphasizes that patients with personal or family history of keloids should avoid skin trauma, as "the best strategy is prevention" 4.
Practical Recommendations
When to Consider Insulin
Based on the available evidence, intralesional insulin may be considered as an alternative or adjunctive therapy when:
- Standard corticosteroid therapy has failed or is contraindicated
- The patient cannot tolerate corticosteroid side effects
- You are seeking comparable efficacy to corticosteroids with potentially different adverse effect profile
Dosing Considerations
The 2025 RCT used intralesional insulin over 4 monthly sessions 1. A 2018 study in breast surgery scars used low-dose subcutaneous insulin injections and showed benefit particularly in patients prone to heavier scarring 5.
Comparative Treatment Hierarchy
- First-line: Intralesional corticosteroids remain the benchmark treatment
- Combination therapy: 5-FU + corticosteroids ± laser therapy shows superior outcomes 2, 6
- Emerging options: Insulin and BTX-A show promise, with insulin demonstrating better efficacy than BTX-A alone 1
- BTX-A: Better suited as adjuvant therapy rather than monotherapy 1, 2
Safety Profile
Insulin demonstrated a favorable safety profile in keloid treatment studies 1. However, the standard insulin warnings apply: risk of hypoglycemia if systemically absorbed, injection site reactions, and lipodystrophy with repeated injections 3.
BTX-A showed significantly lower adverse effects compared to corticosteroids (RR = 0.29) in the 2026 network meta-analysis, suggesting it may be preferable when safety is the primary concern 2.
Critical Knowledge Gaps
- No standardized dosing protocols for intralesional insulin in keloids
- Limited long-term recurrence data
- Insufficient head-to-head comparisons with established therapies
- Lack of FDA approval or formal guideline recommendations
The evidence suggests insulin is a viable option for keloid treatment with efficacy approaching corticosteroids and superior to BTX-A monotherapy, but it should be considered investigational until larger-scale studies establish standardized protocols 1, 2.