Why Understanding Naltrexone Side Effects Matters for Your Healing Journey Do naltrexone side effects go away?  Yes, for most patients, naltrexone side effects are temporary and resolve within a few days to two weeks as the body adjusts to the medication. Here's what you need to know: Most common side effects  (nausea, headache, fatigue, dizziness) typically disappear within 1-2 weeks Timing varies by individual  based on dosage, formulation, and personal physiology Low-dose