The injection may resemble an insect bite and there may be abrasions or puncture marks which are red in color.

Some people may feel slight pain or swelling but all these disappear without any medication given, unless they are very severe, in which case the doctor should be consulted. But by and large, these negative effects of collagen go away in a day or two. The treatment is over within half an hour and the patient can go home taking care not to handle the injected area roughly or to move his facial muscles too much. This is to overcome the fear of the injected collagen spreading to the other areas of the face.

The biggest problem and the negative effect of injection treatments come if the patient has an allergic reaction to the product. Doctors normally check this in advance, much before the therapy is undergone.

Sometimes if the injections are given far apart, there may dent the skin as the parts where the effect of the injection has reached would be filled up and the middle part remains original. Sometimes there may be infection at the site. This can be due to bad hygiene, bad sterilization or surroundings. These are bacterial in nature and can be corrected by the use of antibiotics.