LDN - Low Dose Naltrexone

LDN - Low Dose Naltrexone: Overview

This information regarding Naltrexone is being presented here because of its potential importance to seriously ill individuals and its record of safety.


Dr. Bernard Bihari, MD pioneered the use of Low Dose Naltrexone (LDN) in 1985.

Function; Why it is Recommended

By blocking opioid receptors, naltrexone also blocks the reception of the opioid hormones (endorphins) that the brain and adrenal glands produce.  Many body tissues have receptors for the endorphins, including virtually every cell of the body's immune system.

Naltrexone is usually used in 50mg doses as a drug to help heroin or opium addicts, by blocking the effect of such drugs.  FDA-approved naltrexone, in a low dose (only 3mg), can boost the immune system, helping those with HIV/AIDS, cancer, and autoimmune diseases.  LDN is currently under experimental use for many conditions.  Preliminary results are very encouraging: Naltrexone increases the body's production of the beta and metenkephalin endorphins and blood tests have indicated that it can double or even triple the activity of natural killer cells.  The web site that presents the current available information on this therapy can be accessed by clicking here.

The following diseases have been benefited by LDN use according to Dr. Bernard Bihari, MD.:

How is it possible that one medication can impact such a wide range of disorders? The disorders listed above all share a particular feature: the immune system plays a central role in all of them.  Indeed, research by others has found opioid (endorphin) receptors in brain tumors (both astrocytoma and glioblastoma), breast cancer, endometrial cancer, head and neck squamous cell carcinoma, myeloid leukemia, lung cancer (both small cell and non- small cell), and in neuroblastoma.  These findings suggest the possibility for a beneficial effect in a wide variety of other cancers.

The brief blockade of opioid (endorphin) receptors that is caused by taking LDN at bedtime each night is believed to produce a prolonged improvement in vital elements of the immune system by causing an increase in endorphin production.  Normal volunteers who have taken LDN in this fashion have been found to have much higher levels of beta-endorphins circulating in their blood in the following days.

The treatment seems to work by causing the body to secrete endorphins (metenkephalin and beta-endorphin) which attach to cancers having opiate receptors, shrinking the tumors and inhibiting their growth.  When metenkephalin and/or beta-endorphins are attached to cancer cells while they are dividing, it seems to stimulate a process of programmed cell death or apoptosis, thus killing some cancer cells.  In addition, it is believed that the endorphins act to increase natural killer cells and other healthy immune defenses against cancer.


LDN comes in 3mg capsules and is taken once a day at bedtime.


LDN is non-toxic and has no side-effects.  Its only interaction with other drugs is with narcotics (such as morphine, Demerol and Percocet), which it briefly blocks.

On This Page

LDN - Low Dose Naltrexone:

LDN - Low Dose Naltrexone can help with the following:




LDN - Low Dose Naltrexone may help with Immune System Imbalance (TH2 Dominance) Immune System Imbalance (TH2 Dominance)

Low doses of Naltrexone can help reduce TH2 cytokines to assist in balancing the immune system.




Tumors, Malignant

LDN - Low Dose Naltrexone often helps with Prostate Cancer Prostate Cancer

Dr. Bihari, MD has found that the treatment does not seem to work for prostate cancer patients who have received or are receiving some form of hormone manipulation treatment prior to starting the low dose naltrexone.  This includes patients who have received Lupron, Casodex, Eulexin, DES, or other drugs designed to reduce testosterone.  In addition, patients who have been treated with PC Spes, the herbal preparation with estrogenic effects, also do not seem to respond.

LDN - Low Dose Naltrexone often helps with Chronic Lymphocytic Leukemia (CLL) Chronic Lymphocytic Leukemia (CLL)

CLL is one of the cancers that may respond to LDN.

LDN - Low Dose Naltrexone often helps with Brain Tumor Brain Tumor

The presence of opioid receptors on tumor cells is considered necessary for low dose naltrexone to be beneficial.  Glioblastomas and astrocytomas were thought to be low in these receptors, but this assumption has turned out to be inaccurate.  These tumor types contain sizable numbers of opioid receptors on their cell membranes.

LDN - Low Dose Naltrexone may help with Ovarian Cancer Ovarian Cancer

Dr. Bihari reports some success using LDN on ovarian cancers.

LDN - Low Dose Naltrexone can help prevent the following:

Tumors, Malignant

LDN - Low Dose Naltrexone may help prevent Lung Cancer Lung Cancer

Although lung cancer tissue is low in opiod receptors and thus not so likely to respond to LDN, there may be benefit due to LDN's abililty to increase natural killer cell function.


May be useful: may help with; may help prevent
May be useful:
may help with; may help prevent
Moderately useful: often helps with
Moderately useful:
often helps with
Very useful: is highly recommended for
Very useful:
is highly recommended for