If people engage in strenuous exercise within 24 hours of injection or massage the site of the shot, the Botox relocates, causing a droopy eyelid referred to as "ptosis," according to the Lakeshore Woods Medical Clinic. A droopy eyelid is a mild but uncommon side effect of a Botox injection.
The Lakeshore Woods Medical Clinic states that ptosis is seen in one out of every 1,000 Botox shots. The condition typically clears up within a few weeks. Other side temporary effects are possible and vary by injection site, dose, frequency of injections and physician skill. These include pain, tenderness, swelling and bruising.