Lip Correction - Risks

Complications rarely arise due to injections below the lips. Possibilities include infection of the injected cells, skin necrosis (when skin dies off), the formation of small bubbles, bleeding, bruising, redness, rashes, itchiness, or other allergic reactions.¹⁰

It may also be the case that the results do not match your personal desires and the treatment may need to be repeated.
The transplantation of one's own body fat tissue may produce hardening as well as asymmetries, which can be corrected in a further procedure. During the insertion of contour threads, these may perforate the lip skin.

The use of silicon oil as a filling substance is vehemently discouraged due to the possibility of inflammatory hardenings.¹¹

Your doctor will should clarify these and other risks as well as your personal risk situation in a private conversation.

Sources:

^{1, 3, 6, 8, 11} German Society for Aesthetic-Plastic Surgery (DGÄPC)
² The American Society for Aesthetic Plastic Surgery
⁴ The British Association of Aesthetic Plastic Surgeons
^{5, 7, 9, 10} American Society of Plastic Surgeons