After your treatment, you may experience side effects, such as swelling, redness, pain, bruising, headache and itching at injection site and tenderness. These are typically mild in severity and normally last less than 7 days in nasolabial folds and less than 14–18 days in lips. Swelling may be more likely in patients under 36 years, and bruising may be more likely in patients over 35 years.