I went through something similar with a friend from my support group — her infusions were life-changing at first, but around the 4–6 month mark she felt herself sliding back. Her doctor said that window is pretty common; some people get only weeks, others many months, and boosters are often timed when symptoms start creeping in rather than waiting for a full crash. She found this helpful read with actual timelines: ketamine pain relief how long it lasts . Might help you plan instead of guessing. Honestly, listening to your own symptom pattern is usually the best signal.