What is Low Dose Naltrexone?

Naltrexone is an opioid antagonist (it binds to opioid receptors in the brain without causing opioid effects). It is used in treatment of addictions to opioids and alcohol, and is FDA approved for such uses. Doses for addiction treatment are typically 50 - 150 mg a day for three days a week. At much lower doses of typically 3 to 4.5 mg daily, Naltrexone has been prescribed for various autoimmune disorders, including MS and ALS (amyotrophic lateral sclerosis). Thus the term Low Dose Naltrexone, or LDN.

A recent study of LDN treatment in Crohn's disease was published by Smith et al (Am J Gastroenterol 2007;102:1