Low Dose Naltrexone (LDN): An Overview

What is LDN?

Low Dose Naltrexone (LDN) is a medication that helps regulate a dysfunctional immune system. It is a safe, non-toxic, and inexpensive drug that has been used to treat a variety of conditions, including autoimmune diseases, chronic pain, mental health issues, and even some cancers. LDN works by temporarily blocking opioid receptors, leading to an increase in endorphins, which modulate the immune system, reduce inflammation, and alleviate pain. Additionally, LDN inhibits the activation of microglial cells, reducing neuroinflammation and promoting a balanced immune response. At higher doses, naltrexone is FDA-approved for treating opioid and alcohol dependence by blocking the euphoric effects of these substances. This blocking action also leads to an increase in endorphins, making LDN a safe and effective treatment option for various conditions.

How Does LDN Work?


The mechanism of LDN appears to involve the modulation of neuro-inflammation, specifically through the regulation of glial cells and the release of inflammatory chemicals in the central nervous system. These effects are unique at low dosages compared to the higher dosages approved by the Food and Drug Administration (FDA) for treating alcohol and opioid dependence. In addition to this LDN temporarily blocks opioid receptors, leading to an increase in the production of endorphins. These endorphins help regulate the immune system by promoting a balanced immune response and reducing inflammation


Functional Medicine Perspective

From a functional medicine perspective, LDN is valued for its ability to address the root causes of chronic conditions by regulating the immune system and reducing inflammation. It offers a holistic approach to treatment, focusing on improving overall health and well-being.

Conditions Treated with LDN LDN has been found to be effective in treating a wide range of conditions, including:

  • Multiple Sclerosis (MS)

  • Crohn’s Disease

  • Fibromyalgia

  • Chronic Fatigue Syndrome (ME/CFS)

  • Complex-regional pain syndrome

  • Chronic Pain

  • Mental Health Issues

    • Anxiety

    • Depression

    • PTSD

  • Autism

Immune System Modulation

  1. Opioid Receptor Blockade: LDN temporarily blocks opioid receptors, leading to an increase in the production of endorphins. These endorphins help regulate the immune system by promoting a balanced immune response and reducing inflammation.

  2. Microglial Cell Inhibition: LDN inhibits the activation of microglial cells, which are involved in neuroinflammation. By reducing the activity of these cells, LDN helps decrease the release of inflammatory chemicals in the central nervous system.

  3. Cytokine Modulation: LDN influences the production of cytokines, which are signaling molecules that play a crucial role in the immune response. By modulating cytokine levels, LDN helps reduce chronic inflammation and promote immune system balance.

Brain Inflammation Modulation

  1. Endorphin Production: The increase in endorphins due to opioid receptor blockade not only helps regulate the immune system but also has anti-inflammatory effects on the brain. Endorphins can reduce the production of pro-inflammatory cytokines and promote a healthier brain environment.

  2. Glial Cell Modulation: LDN modulates the activity of glial cells, which are key players in neuroinflammation. By reducing the activation of these cells, LDN helps decrease brain inflammation and protect neural tissue.

These mechanisms make LDN a promising therapeutic option for various conditions involving immune system dysregulation and chronic inflammation.

Dosage and Administration LDN is typically prescribed in doses ranging from 0.001mg to 16 mg per day, with most studies using a dose of 4.5mg per day. There is a slow and steady  titration protocol to find the most optimal dose.The medication is usually taken at bedtime.

Safety and Side Effects LDN is considered safe and well-tolerated. Common side effects are mild and may include vivid dreams, sleep disturbances, and gastrointestinal issues. We can lower the risk of these side effects through slow and steady titration. These side effects often diminish over time.