Low Dose Naltrexone

Low Dose Naltrexone: A beneficial modulator of immune function

An immune modulating agent that can help patients with HIV, cancer, auto-immune disease and central nervous system disease?  It’s available, it’s relatively inexpensive, and it has application to autism, Lyme disease and thyroid disorders also through its beneficial effect on the immune system.  It is called Low Dose Naltrexone (LDN).

Naltrexone in higher doses (50mg) was approved by the FDA in 1984 for helping heroin or opium addicts, as it blocked the effect of such drugs.  In lower doses it has much broader medicinal use – in fact, if you think of any condition that involves immune dysregulation, there may well be an application for LDN.

Bear with me for a minute while I explain the mechanism.  Taking LDN at night creates a brief blockage of opioid receptors between 2am and 4am.  This in turn causes a compensatory increase in endorphins and enkephalins, vital elements of the immune system.  So by influencing immune “chemicals” we can influence immune function.  LDN acts as an immune balancer not just an immune booster, which makes it so useful in autoimmune illnesses, where the immune system is already over-reacting.  In cancer, another significant application, LDN seems to increase opioid receptors on the tumor cell membranes, attracting more endorphins which can trigger apoptosis (cancer cell death), thus assisting in the shrinkage of tumors.

Who Else Can Low Dose Naltrexone help?

Those with auto-immune illnesses such as rheumatoid arthritis, Hashimoto’s thyroiditis, Crohns disease and lupus; neurodegenerative diseases such as ALS, Lyme disease, MS and autistic-spectrum disorders; many kinds of cancers; and infectious diseases such as HIV/ AIDS.

Low Dose Naltrexone Side Effects

LDN has very few side effects. Some people report some difficulty sleeping in the first week or so, which typically resolves spontaneously.  There are a few cautions – for example, a patient with Hashimoto’s thyroiditis with low thyroid function will need to monitor their thyroid medication carefully, as when the thyroid starts functioning better after the LDN, the regular dose of medication may become too much, creating a hyperthyroid situation.  The lowest possible dose (1.5mg) is a good starting point in these cases.  LDN should not be taken by those on narcotic pain medications, or by transplant recipients.

Low Dose Naltrexone Uses

I have used LDN in my autistic-spectrum patients, and have seen good benefit.  Some kids do get a little more hyper for the first week or so, and may not sleep as well, but beyond that I have seen significant improvements in mood and behavior.  Parents report their children seem calmer, less reactive, and their overall health improves as their immune system is bolstered.  Since immune activation in the gut and in the body in general can fire all kinds of inflammatory chemicals to the brain, crossing the blood-brain barrier and triggering behavioral and cognitive changes, we can see that calming immune hyperactivity can calm brain hyperactivity!

My Lyme patients have reported less pain, improved sleep, and accelerated recovery.  We know that tick-borne pathogens put a significant hold on the immune system, so the LDN can help overcome that and get the immune system fighting more efficiently again.

Anecdotally, I have heard of LDN assisting in weight loss, however there is limited research on this use alone.

LDN is a prescription medication, and is available from several compounding pharmacies such as San Diego Compounding Pharmacy.  Pharmacist Jerry Greene will compound LDN in any strength from 1.5mg to 4.5mg.  Contact Adriana to schedule a consultation with Dr. Nicola if you would like to discuss whether LDN would be a good choice for you or your child.


  1. Hi Nicola,

    ND’s in CA can prescribe LDN? I just moved to CA from WA and want to make sure it’s within our prescriptive authority here in CA.