No, Botox does not cause keloids—in fact, it is used to treat them.
Botulinum toxin type A (Botox) is actually a therapeutic agent for keloid treatment, not a cause of keloid formation. The confusion in your question likely stems from misunderstanding the relationship between Botox and keloids.
Evidence for Botox as Keloid Treatment
Multiple high-quality studies demonstrate that intralesional Botox injection is an effective treatment modality for existing keloids and hypertrophic scars:
A 2022 clinical and pathological study showed highly significant improvement in keloids and hypertrophic scars treated with BTX-A injections, with statistically significant differences in Vancouver Scar Scale, Observer Scar Assessment Scale, and Patient Scar Assessment Scale scores (p ≤0.001) after three monthly sessions 1.
A 2023 randomized controlled study in children with post-burn hypertrophic scars and keloids demonstrated dramatic improvement in vascularity, pliability, and height of lesions injected with botulinum toxin, along with relief of associated itching and pain 2.
A 2019 systematic review and meta-analysis comparing BTX-A to corticosteroid injections found significant differences favoring BTX-A in Visual Analog Scale scores (P<0.001) and scar width reduction (P=0.00) 3.
A 2025 study showed BTX-A combined with superficial radiotherapy after chest keloid surgery resulted in higher total effective rates, greater patient satisfaction, and lower Vancouver scar scale scores compared to radiotherapy alone (P<0.05) 4.
Mechanism of Action
Botox works therapeutically on keloids by reducing tension in the wound area and modulating fibroblast activity, thereby preventing excessive collagen deposition that characterizes keloid formation.
Important Caveat
One 2014 in vitro study found no effect of BTX-A on keloid fibroblast proliferation or cytokine expression in cell culture 5, suggesting the therapeutic mechanism may be more related to mechanical tension reduction rather than direct cellular effects.
Clinical Bottom Line
If you are considering Botox for cosmetic or therapeutic purposes, there is no evidence it causes keloids. Conversely, if you have existing keloids, intralesional BTX-A injection (typically 1 session per month for 3-6 months) represents a viable treatment option, particularly when combined with other modalities like superficial radiotherapy or corticosteroids.