Low-dose naltrexone — typically 0.5 to 4.5 mg daily — is an off-label treatment option being explored for fibromyalgia. Unlike the high-dose form used for opioid or alcohol dependence, LDN temporarily blocks opioid receptors in a way that appears to reduce central pain sensitivity. Research suggests it may help decrease inflammation in the nervous system, improve sleep, and reduce fatigue and widespread pain. It is generally well tolerated, with mild side effects such as vivid dreams or headaches in some patients. While studies are small and still ongoing, many clinicians consider LDN a promising option when standard fibromyalgia treatments aren’t enough.