dilution of BoNTAs: my way
Objectives: To present the rationale and clinical outcomes of a reduced-volume dilution approach, and to demonstrate its advantages in terms of precision, safety, and reproducibility compared to traditional high-volume dilutions.
Introduction: Botulinum toxin A (BoNTA) is widely used for aesthetic and therapeutic purposes. Dilution practices can influence diffusion, efficacy, and safety. In December 2023, I published a protocol introducing a mid-range dilution strategy for 50U and 100U vials, designed to allow injection of higher total units while minimizing injection volume and reducing unwanted diffusion.
Materials / method: BoNTAs (50U and 100U vials) were reconstituted using a reduced volume of diluent—half of the conventional volume—to achieve a denser solution. 1,25 ml for 100Units and 0,63 ml for 50U regardless the brand. This allows higher total units to be injected per session while maintaining smaller injection volumes. Clinical cases over 2 years were reviewed to evaluate efficacy, diffusion, and patient satisfaction.
Results: The reduced-volume dilution allows accurate targeting of specific muscles with minimal spread to adjacent tissues especially for particular off label indications. Patients experienced consistent aesthetic results and reduced incidence of unwanted diffusion-related side effects. The protocol proved reproducible across different practitioners and indications, confirming its safety and effectiveness.
Conclusion: This mid-range dilution strategy remains a valid and practical approach for BoNTA administration. By balancing total units, injection volume, and diffusion control, it enables precise, predictable results. The method demonstrates that thoughtful reconstitution of BoNTAs can optimize outcomes while reducing risks, confirming the lasting utility of the original published protocol.
