lowdosenalIt isn’t difficult to find information about the use of small amounts of naltrexone hydrochloride for the treatment of neurological disorders, particularly multiple sclerosis.

Naltrexone has been available for decades as a treatment for a handful of addictive disorders. It proved to be less effective than hoped and soon fell into disfavor. However, one New York physician, Dr. Bernard Bihari, noticed that when his AIDS patients used naltrexone for their addictions, they also experienced marked improvements in the neurological symptoms associated with AIDS.

For a variety of reasons, Dr. Bihari tried lower doses of naltrexone and observed that his patients still had symptoms improvement, even when doses were 3mg (approximately 1% of the standard daily dose when used for addictions). There appeared to be a connection between autoimmune symptoms and the use of naltrexone in low doses. Cancer patients also showed improvement. People who suffered from multiple sclerosis were offered this low dose of naltrexone and also reported improvements in all symptoms associated with that disease.

Numerous compounding pharmacists were in contact with Dr. Bihari and began preparing a 3mg strength of naltrexone. Initially, we used commercially available naltrexone tablets (i.e., Revia). Because the drug had been around longer than its patent life the pure powdered form of naltrexonehydrochloride became available to compounders.

The information spread and many hundreds of people began using what had become known as “LDN”, actually a 3.0mg dose of naltrexone, mixed with simple, non-allergenic fillers. It was concluded that calcium might interfere with absorption of the drug, so compounders were informed to not use calcium as one of the fillers. It was also deduced that naltrexone was “doing something” to the immune system via the systems in the body that are associated with endorphins. As naltrexone is rapidly absorbed and excreted, compounders and prescribers decided to not use any of the slow release fillers in the preparation of LDN.

The side effect profile is minimal. Some people report some stiffness and others tell us about more vivid dreaming. Both of these seem to resolve within just a week or so of starting.

Naltrexone retains its anti-narcotic effect even at these very low doses. People using any opioid should not be using naltrexone in any strength.  A doctor reported serious withdrawal-like symptoms in a patient who was using hydrocodone and started using LDN.

Over time, some prescribers decided that there might be a relationship between dose and effect – as is common for many drugs. While the 3.0mg capsules remained popular, more people began using 4.5mg. The question about dose response is not resolved, but beliefs persist. The 4.5mg has gained in popularity and currently we prepare about equal amounts of 3.0mg and 4.5mg. We also make it in lower and higher strengths – though we don’t have a record of ever preparing anything over 6mg.


Five items are required when writing a prescription for Low Dose Naltrexone:

1. It is important to note what strength is being prescribed. 1.5mg, 3.5mg and 4.5mg are all common doses.

2. What is the quantity of capsules?

3. What are the instructions?  An example of the most common instructions are: Take 1 capsule at time of sleep.

4. How many refills are authorized?

5. A doctor’s signature.