Can Botox Be Safely/Successfully Used to Decrease Muscle Mass in the Deltoid Muscles?

Yes BOTOX will reduce the bulk of the deltoid through paralysis and disuse atrophy.  This will be at the expense of function.  Your upper arms are fantastic and I would recommend tailoring rather than weakening the shoulder mass with BOTOX.  I as a doctor would turn you away for treatment.

Botox will reduce muscle activity but not reduce muscle mass.  There would be too many units needed to inject you safely. You would also risk losing important function of extending your arm at the elbow, such as getting out of a chair or bed by pushing yourself up.

Hi Gems.  While the concept of reducing (body) muscle mass may seem interesting to consumers, most physicians will not inject for these purposes.  It's true that Botox can cause a form of muscle atrophy with repeated use, but the muscles in your face are much different and much less hearty than the deltoids. 

The number of units of Botox required to properly relax the deltoid would be very large and would be enough to discourage any credible physician we know from doing the treatment.  A normal dose for the facial area is usually between 20 and 60 units and this area would likely require hundreds.

It would also be extremely expensive for you and we do not advise it.

I would not recommend using Botox to lessen the size of your Deloid muscle-there is no study on this and I would like to see you go through with this

If you want to reduce the size of a particular muscle, stop exercising that muscle.  Large amounts of Botox can have life-threatening consequences and should not be done.  Botox can be used to relieve muscle spasticity under very specific circumstances, but not to reduce the size of large muscles.