Background: Botulinum toxin A (BTX-A) is clinically used for muscular disorders, migraine, hyperhidrosis and cosmetics by preventing the release of neurotransmitter acetylcholine into synaptic cleft. Objectives: The aim of this study is to investigate the efficacy and safety of newly developed BTX-A product (Korea) compared to conventional BTX-A (USA) for the reduction of muscle hypertrophy in Myostatin-deficient (Mstn^-/-) mouse. Methods: Two different BTX-As were injected on the hindlimb of Mstn^-/-mouse. Since then, serial sciatic nerve conduction study (NCS), X-ray, 3D micro-CT and muscle biopsy was done. Results: Administration of BTX-A in both product group induced denervation-mediated atrophy and alleviated muscle hypertrophy generated in Mstn^-/- mice. On day 56, newly developed BTX-A product group showed significant suppression in NCS compared with conventional BTX-A product group. Conclusion: In this study, the results suggest that both BTX-A regulate skeletal muscle size and the number and diameter of myofibers. Also, newly developed BTX-A product seems to have longer duration compared with conventional BTX-A product in the ability to act in a local area.