Botox can cause temporary redness, swelling, tenderness, or bruising at the injection site. You may get flu-like symptoms like fever, body aches, or nausea after Botox. Botox may cause headaches, ...

Botox (onabotulinumtoxinA) begins to take effect within two to five days after you’ve had the injection. That said, it can take up to several weeks for you to see the full results, and the timeline ...