Low Dose Naltrexone (LDN)

0.5, 1.5 mg, 2 mg, 2.5 mg, 3 mg, 3.5 mg, 4 mg, 4.5 mg, 5 mg

Naltrexone is an oral opiate receptor antagonist. It is derived from thebaine and is very similar in structure to oxymorphone. Like parenteral naloxone, naltrexone is a pure antagonist (i.e., agonist actions are not apparent), but naltrexone has better oral bioavailability and a much longer duration of action than naloxone. Clinically, at high dose naltrexone is used to help maintain an opiate-free state in patients who are known opiate abusers. Low doses of naltrexone (LDN) can reduce autoimmune activity and to modulate the immune system.

When LDN attaches to opioid receptors, the drug blocks endorphins from attaching to them, which causes the body to release additional endorphins. A surge in endorphins causes increased activity from stem cells and immune cells, making your immune system work more efficiently. Endorphins are hormones secreted by the brain which bind to opioid receptors, producing analgesic effects. 

Naltrexone is contraindicated in patients with known hypersensitivity to naloxone or nalmefene because these three drugs are all structurally similar. Naltrexone is contraindicated in patients who are receiving opioid analgesics, partial opiate agonists (e.g., buprenorphine), those with current physiologic opioid dependence, and those in acute opioid withdrawal.

LDN is well-tolerated because the dose is low. Some patients can experience insomnia, vivid dream, or headaches upon initiation. These side effects typically resolve with time, however, you may try taking LDN earlier in the day to avoid side effects associated with insomnia/vivid dreams.

Store this medication at 68°F to 77°F (20°C to 25°C) and away from heat, moisture and light. Keep all medicine out of the reach of children. Throw away any unused medicine after the beyond use date. Do not flush unused medications or pour down a sink or drain.