Lumps that develop or persist years after lip filler treatment can be due to several factors. In many cases, these represent residual filler material that has not fully broken down. Hyaluronic acid fillers typically dissolve within 6–18 months, but in some people they can last longer, especially if higher volumes were placed or if the product integrated deeply. Other possibilities include: Filler migration – when the product moves slightly from the original injection site, creating unevenness or palpable bumps. Nodules or fibrosis – scar-like tissue that can form around the filler. Natural lip gland or tissue irregularities – which may feel more noticeable after filler. Treatment options may include: Hyaluronidase injections – an enzyme that can dissolve hyaluronic acid-based fillers quickly if the product is still present. Massage or conservative management – sometimes recommended for minor lumps. Surgical removal – rarely needed, but an option for firm nodules not responsive to hyaluronidase. A careful in-person evaluation is required to distinguish between residual filler and scar tissue, but in many cases, hyaluronidase can significantly improve or resolve lumps even years later if filler material remains.