Why do I get shortened duration of Botox over time?

The duration of your botox effect may be related to dose, interval between injections, the mass of muscle targeted, and technique of injection.  Potentiation from antibodies and an immune system response after multiple doses may also affect the duration of effect.  Some patients with active expression will require higher doses, more frequently, and by experienced injectors.  If the response continues to be disappointing, discuss with a qualified surgeon to consider alternative neurotoxins, radiofrequency modalities, or even surgical correction for the unwanted expression lines.

In general Botox lasts 3-4 months and patients tend to be fairly consistent with how long the individual effects last.  It may be injector technique or that more product is needed to produce the results that you like.  Placement of the Botox and dose can alter the results.

This is difficult to answer without an in-person evaluation, but it may be that more Botox is needed to get the results you want. See an expert. Best, Dr. Emer