Just like any form of lip augmentation, it has its side effects and for some people it's minimal while for some people the side effects can be very harmful. Here are some side effects of using collagen based lip injections;

1. Risk of infection

2. Uneven lips

3. Bumps on the lips

4. Prolonged swelling and bruising that may last for a couple of days

5. Ulceration and scarring of the lips

Damage of blood vessels

6. Possible allergic reaction to the type of collagen used.