Do you feel like only one side changes first after Botox?

I got Botox, but it seems like only the left side changed first.

I had the procedure done on both sides exactly the same.

After a few days, it seems like something has changed on the left side.

The right side feels almost exactly the same.

Could it be because the amount administered is too small?

I received about 10 units.

Originally, aren't both sides supposed to change equally?

Maybe it's because the effects are still settling in,

Is it possible for there to be a difference between the left and right sides?

I'm not sure if it's a subtle difference caused by the muscles, or if it's something else, or if it's a side effect; what exactly is it?

I'm not entirely sure what the cause is either, so I'd appreciate your advice.