This is subjective since many factors are at play. Our bodies, lifestyles, and aftercare routines all vary, which affects healing time. According to Piercer David Wilkins, the healing process typically takes around eight to 12 weeks, but it can also reach up to 16 weeks (via YouTube). Wilkins explained that the timeline varies depending on the person and the placement of their piercing. During the first couple of weeks, he recommends avoiding any unnecessary contact with your piercing (tugging, playing with, or biting it) as it can further delay healing.
Patience is important in the healing process. "You're healing a fistula, and that's a tunnel of scar tissue being built around the jewelry, so it takes time" celebrity piercer Brian Keith Thompson explained to Byrdie, adding, "The body's going to seal off the exterior first to prevent bacteria, then it's going to start healing inwards, so it takes a while."
The Association of Professional Piercers advises people with new lip piercings to keep an eye out for any unusual side effects including "fever, chills, nausea, vomiting, dizziness, or disorientation." If this happens, they advise getting in touch with a medical professional as soon as possible.