Ann Dermatol.  2023 Oct;35(5):355-359. 10.5021/ad.22.155.

A Double-Blinded, Randomized, Dose-Comparison Pilot Study to Comparatively Evaluate Efficacy and Safety of Two Doses of Botulinum Toxin Type A Injection for Deltoid Muscle Hypertrophy

• Koh YG
• Shin SH
• Kim KR
• Yeoum SH
• Choi WW
• Park KY

• KMID: 2546613
• DOI: http://doi.org/10.5021/ad.22.155

Abstract

Background
Botulinum toxin type A (BTX-A) injection is being widely used off-label for muscular hypertrophy, including deltoid muscle hypertrophy. However, very few studies have evaluated the optimal dosage and its clinical response.
Objective
This study aimed to assess the efficacy and safety of different doses of Prabotulinum toxin A (PBoNT) for treating deltoid muscle hypertrophy.
Methods
Twelve particiapants with bilateral deltoid muscle hypertrophy were enrolled and randomly received either 16 U or 32 U of PBoNT. In each participant, the same dose was administered to both deltoid muscles. Both participants and evaluators were blinded. Deltoid muscle thickness and upper arm circumference were measured on day 0, and weeks 2, 4, and 12 after the PBoNT injection.
Results
Upper arm circumference significantly decreased in both groups; however, deltoid muscle thickness was reduced in the 16 U group only. No major complications were reported in both groups. However, a few minor complications were reported in the 16 U injection group.
Conclusion
Both 16 U and 32 U of PBoNT intramuscular injections are safe and effective in treating deltoid hypertrophy.

Keyword

Botulinum toxins; Deltoid muscle; Hypertrophy