How long does 2 units of Botox last?

A dose of 2 units of Botox per side to treat the crow's feet is a very low dose.  I would say a more typical dose would be somewhere around 10 units per side.  It is possible that you could get some minor improvement with a 2 unit dose and the effect would most likely only last for a few months.  Usually using a higher dose will make the effect last longer but there is a point reached where using more will not help with the longevity of the effect.  

Botox lasts 3-4 months if the proper amount of units were applied, if you were under-dosed it may only last 4-6 weeks 

With the treatment of crow's feet, not only is the severity of lines important, but also the amount of area to be treated.  Typically 4-6 sites on each side will be injected with 2-2.5 units of Botox each, for a total of 8-12 units per side.  You will likely see a return of wrinkles sooner than 3 months if less than this dosage is used.  

Are you sure your doctor was not talking about the fine lines directly below your lower eyelids? In those situations 2 units of Botox seems appropriate. However, 2 units of Botox around the eyes in the crow's feet area will not do anything for you. Its hard to tell exactly how many units you would need without examining you, but the average is at least 10-15 units per side. Hope this helps!

Hi Delilah.  We're not sure why any injector would have recommended 2 units per eye.  We would guess that you will see no appreciable difference before and after this injection.  Not only that, but if you did see some small effect, it will go away in a matter of weeks.  8-10 units of Botox per side would be much more appropriate.