Naltrexone is a drug used mainly against alcohol and opioid dependence and as an antidote for morphine overdose. It has been used in alternative medicine as an off-label drug as low-dose naltrexone (ranging from 1-5 mg per dosage) since the ’80s for many different diseases to varying degrees of success and scientific data.
In low doses (1-5 mg, also known as LDN) it seems to act as a glial modulator. It binds to specific receptors that trigger a chain reaction leading up in the activation of the inflammatory system through various markers like interleukin-1, TNF-α, and interferon-β, so the LDN inhibits the inflammatory cascade to some extent. Some studies show as well that it may inhibit the mTOR signaling pathway.
Its mechanism of action suggests that LDN may be used in a number of different cancer types due to the fact that it inhibits pathways that are common for most cancer cells. Some laboratory studies have been done against some types of cancer (breast, melanoma, neuroblastoma, amongst others).
We believe that LDN has limited use and there isn’t at the moment enough data to warrant more widespread use. It may also be hard in most countries to find the required 1-5 mg tablets (in some countries – like the USA – it is sold as an over-the-counter supplement), but its safety profile is good enough so that patients usually don’t experience any side effects and being an oral drug, it is easy to use.