All botulinum neuromodulators (BOTOX, DYSPORT, and XEOMIN) can cause eyelid drooping during treatment. In clinical trials of these drugs submitted to the FDA, and available in the package insert: The incidence of eyelid drooping with BOTOX was 3%, with DYSPORT was 6%, and with XEOMIN was 19%(although with XEOMIN, placebo drooping was 9%). So all of these drugs can cause eyelid drooping as a side effect of treatment. These are not direct comparisons, but the data submitted to the FDA for approval.
More skilled and experienced injectors will have this complication occur much less frequently, but all experienced injectors have seen ptosis side effects.
Certain patients may have a pre-existing mild droop or ptosis of the eyelid, and even small doses of botulinum product may worsen this droop. Also, the drug may migrate to the lid after injection and cause drooping, or it may weaken accessory muscles that help mask the minimally droopy eyelid before treatment. Certain eyedrops will help ptosis or drooping of the eyelid. In addition, very experienced injectors can administor small amounts of BOTOX into the medial and lateral eyelid lifters to increase central lifting, and thereby improve eyelid drooping.