Yes, filler can often improve smile lines, but the key is treating the cause of the crease rather than simply filling the line itself. From your photo and description, it looks like the crease near your mouth has likely been part of your natural facial anatomy for quite some time. That's actually common—some people are born with deeper folds due to their bone structure, facial fat distribution, and the way their muscles move. The good news is that this type of crease can often be softened while still looking natural. Rather than injecting a large amount of filler directly into the line, many experienced injectors will first assess whether the surrounding areas—such as the cheeks or the corners of the mouth—have lost support. Restoring that support can lift the tissues slightly and reduce the appearance of the crease without making the area look puffy. For the area around the mouth, hyaluronic acid fillers are usually the preferred choice because they are soft, flexible, and can be adjusted if needed. The exact product depends on your anatomy, but commonly used fillers include those designed for moderate facial folds and contouring. One of the biggest concerns patients have is looking "overfilled." Fortunately, that is usually avoidable with a conservative approach. It's often better to start with a small amount of filler, reassess after it settles, and add more only if necessary. This typically produces a much more natural result than trying to erase every crease in one treatment. It's also important to remember that smile lines are a normal part of facial expression. The goal isn't to eliminate every line, but to soften them while preserving your natural movement and facial character. Based on your photo, I do think you could be a good candidate for filler, and with careful placement, it's very possible to improve the crease without creating an unnatural appearance. A subtle treatment plan usually provides the most balanced and aesthetically pleasing outcome.