LDN works by blocking the natural opiate receptors. The body then responds by regulating the synthesis of its endogenous opiates, known as endorphins.
This means the body ends up with a hundred or a thousand times more endorphins and a better-functioning immune system.
Essentially, when using a very low dose, about one-tenth to one-fifteenth of the amount you'd use for opioid addiction, or less, naltrexone works like a form of hormesis. This is when a compound that's toxic at high doses ends up having the opposite effect in small or minute doses.
LDN is thought to work independently from its action on opioid receptors by blocking glial cells, which are a type of central immune cell. When activated, the glial cells are thought to cause pro-inflammatory effects that result in pain sensitivity, fatigue, cognitive disruptions, and sleep disorders.
Blocking this action of glial cells is believed to provide neuroprotective and analgesic effects. Most research suggests that LDN takes about one month to start reducing pain. Therefore, a 3-6 month trial is recommended.