Should I have 40 units of Botox every 6 months or 20 units every 3 months?

Thanks for your question.  You never want to over do the Botox.  Since you have not had the injections before I would opt for the 20-30 units per side and see how it does.  More can be added but none can be taken away.  As for the interval, Re-inject as the effect is wearing off which can be well beyond the 3 month mark that is seen in the forhead and crows feet.  I have had it last as long as 6 months or longer using 20 units.  Good luck.
Dr. ODell

Thank you for your question!  I have injected botox for temporalmandibular joint (TMJ) pain / masseter (jaw muscle) reduction almost daily for 8 years and know that this can be a life changing treatment for patients.  I have had optimal results with 20-24 botox units per side every 3-4 months (40-48 units total).  Having said that, each patient is different and some do well with higher or lower doses.  I recommend that my patients return every 3-4 months for a year to help reduce the size of the masseter and therefore break the habit of clinching and grinding.  Some patients do not require any more treatments after a year, and some may need more treatments to help stop the grinding and get pain relief.  I hope this information is helpful.  Be sure to seek out an expert injector who frequently treats this area.  Best of luck! 

The answer depends on your muscles. Many dermatologists and plastic surgeons use 20-30 units in the glabella (the approved dose for this site is 20 units). In my practice, I try to use 25 units and find that this keeps most people good for 4 months. My preference is not to bring people back at 6 months because in most instances, one ends up starting over again.