Subcutaneous botox
Reviewed by Eduardo Morera Serna

The authors of this paper performed a double blind, randomised, prospective trial on 19 patients receiving intramuscular botulinum toxin injections on one side of the forehead and subcutaneous injections on the other. Objective assessment of brow elevation and subjective self-evaluation of appearance were conducted at two weeks, two months and four months post-injection. Discomfort during injection, tenderness and bruising were also examined on both sides of the forehead. Results showed no difference between subcutaneous and intramuscular injections regarding brow position at the three controls and only a mild difference on subjective appearance at four months, favouring intramuscular plane of injection. Pain, tenderness and bruising were less with the subcutaneous injections. Anecdotal reports can be found in the literature stating the effectiveness of subcutaneous botulinum toxin injections, but so far no well-conducted study has been made to support this observation. Reduced pain during injection favours subcutaneous administration; nevertheless intramuscular plane seems to be related to a longer lasting effect. An interesting paper with useful data for clinical practice.

Subcutaneous vs. intramuscular botulinum toxin split-face randomized study.
Gordin EA, Luginbuhl AL, Ortlip T, et al.
JAMA FACIAL PLASTIC SURGERY
2014;16(3):193-8.