Lumps and bumps after dermal fillers injections can happen with any cosmetic injection material (fat, hyaluronic acid, collagen, etc). Most lumps are temporary and due to swelling. Small bumps or lumps after cosmetic injection or augmentation typically resolve in a few days, but possibly a couple weeks. The lip bumps may be the product material, bruising / swelling, scar tissue, or combination.
Your plastic surgeon or dermatologist may massage to help smooth the area. Alternatively, hyaluronidase may be injected into the bump to help dissolve the material, which works especially well with hyaluronic acid fillers such as Restylane or Juvederm. Lumps from the material itself generally resolve as your body naturally dissolves the product. Scar tissue, especially with repeated injections, may occur too. Speak to a plastic surgeon or dermatologist regarding any concerns you may have for a comprehensive evaluation and help determine appropriate options for you. Best of luck.
Dr. Chaboki