It depends heavily on what "low" actually means for your situation. A 503 to 507 can still work with a strong GPA, deep and consistent clinical experience, a mission-aligned school list, and DO programs included in that list. Below 500, an MD path becomes genuinely difficult regardless of how strong the rest of the application is.
If you're sitting below your target score, ask yourself honestly whether a focused retake is likely to add 5 or more points — that's usually the threshold where a retake is worth the time and risk. If the honest answer is no, it's often smarter to build the rest of your application as strong as possible and target schools that fit your current stats rather than gambling another attempt on the exam. A diagnostic conversation with a tutor can help you make that call with actual data instead of guessing.