laser treatment   After a filler injection, normal reactions and side effects can include swelling, redness and tenderness or sensitivity, mild discomfort, lumps or bumps More Services Certified trainer for various filler company, With 10 years of experience. botox injection After a Botox injection, normal reactions and side effects can include temporary redness or swelling at the injection site, mild bruising, localized pain or tenderness, headache, flu-like symptoms, drooping or heaviness of the eyelids, and temporary weakness. filler injection You may experience temporary side effects including bruising, swelling, and redness in the injected area, which will quickly fade away.