Low-Dose Naltrexone (LDN)


Naltrexone blocks opioid docking sites on cells and is used in clinical practice in people trying to rid themselves of addiction to opiates. Low dose naltrexone (LDN) refers to the use of naltrexone in doses approximately one-tenth those used for drug/alcohol rehabilitation purposes.


How does LDN work?

LDN is understood to encourage the body to produce endorphins which alters the action of the immune system


How is LDN administered?

LDN is taken orally, either as capsules or in a liquid form.


LDN and MS

There have been several pilot trials but little proven and documented evidence to suggest that LDN is beneficial for people with MS. However many do find it helps relieve symptoms. Due to the lack of evidence it is not an approved MS treatment and one that GPs have a choice in prescribing, or not. There is no requirement for GPs to prescribe LDN.


Research into LDN and MS

The first formal clinical research into the effect of LDN on immune diseases took place at Penn State University’s Hershey Medical Centre. This was looking at its effect on people with Crohn’s Disease, an inflammatory disease of the digestive tract. In the open label study, 17 people took LDN daily in addition to their other medication. All bar two of the participants exhibited a response to therapy. The treatment was well tolerated with the most common side effect being sleep disturbances, which affected seven participants.

A pilot study of low dose naltrexone therapy in multiple sclerosis was run by the Milan neurological researcher, Dr. Maira Gironi and colleagues. The Italian pilot study involved 40 people with primary progressive MS. Participants received 4mg of LDN for six months, with researchers looking primarily at safety but also at the effect on spasticity, pain, fatigue, depression, and quality of life.

The results were published in September 2008 and showed LDN was safe and well-tolerated. There was a significant reduction of spasticity during the trial, but half the participants reported an increase in pain. There were no significant changes to measures of fatigue, depression or quality of life during the trial.

A pilot clinical study, by Bruce Cree, MD, Douglas Goodin, MD, and co-researchers at the Multiple Sclerosis Center at UCSF, published a “Pilot Trial 0f Low Dose Naltrexone and Quality of Life in MS” The trial which was presented at the 2008 American Academy of Neurology, suggested that LDN may improve several measures of mental health quality of life and pain, and that further testing in larger numbers of individuals may be warranted.

The clinical trial initially involved 80 people with all types of multiple sclerosis; however the finished trial only had complete data on 60 of the original participants as a result of drop outs and incomplete data. All participants received both the LDN for eight weeks and inactive dummy pills (placebo) for eight weeks in a study design known as “crossover,” with one week free of treatment in between. Some received the LDN during the first eight-week period and some during the second eight-week period. Participants were given a Web-based battery of quality of life tests called the MS Quality of Life Inventory (MSQLI) before the first treatment period and after each study period. The MSQLI asks the individual to report on mental and physical aspects of their condition including mental health, pain, perceived cognitive deficits, fatigue, and visual, bladder and bowel symptoms and sexual satisfaction.

The investigators found that LDN improved quality of life in the areas of mental health, pain, and self-reported cognitive function, but no impact was observed on aspects of physical quality of life such as fatigue, bowel and bladder control, sexual satisfaction, and visual function. Vivid dreaming was reported during the first week of treatment by some patients, but no other adverse effects were reported. The investigators emphasized that the results did not support the use of LDN instead of proven MS treatments.


Side Effects

Because LDN stimulates the immune system, it should not be taken by people also taking one of the DMTs that suppress the immune system. The full strength drug should not be used in conjunction with an opioid containing medication or with people with hepatitis or liver problems. The low dose treatment is not associated with significant side effects.


What to do about a bad reaction to medication

Reports from health professionals are preferred as doctors and other prescribers, pharmacists and nurses usually are able to provide more detailed information about the medications in use and other medical history from patient records that are helpful in evaluating the adverse reaction. However anyone may report a suspected adverse event or reaction to medication taken to the Centre for Adverse Reactions Monitoring (CARM).

For instructions and further information https://nzphvc.otago.ac.nz/reporting/


Availability in New Zealand

The only medicine containing Naltrexone which is approved in New Zealand is Naltraccord.


Further Information

Low Dose Naltrexone

The LDN Research Trust

Medsafe sheet for Naltrexone


  • Smith JP, Stock H, Bingaman S, et al. Low-dose naltrexone therapy improves active Crohn’s Disease. American Journal of Gastroenterology 2007;102:1-9.
  • Gironi M, Martinelli-Boneschi F, Sacerdote P, et al. A pilot trial of low-dose naltrexone in primary progressive multiple sclerosis. Multiple Sclerosis 2008;14(8):1076-1083.
  • Pilot trial of low dose naltrexone and quality of life in MS. Bruce A.C. Cree, Elena Kornyeyeva, Douglas S. Goodin
    Multiple Sclerosis Centre at UCSF.