First the Basics: LDN 101

"LDN" (low dose naltrexone) is an "alternative" medication used with surprising success in treating immune disorders, both autoimmune and immune deficient. Taken orally at bedtime, LDN works by briefly blocking opiate receptors, thereby "tricking" the body into increasing endorphin production. Endorphins being a central part of the immune system, increasing their production has been shown to help correct immune defects.


FAQ's on LDN* (Low Dose Naltrexone)

What is Naltrexone?
Naltrexone is short for Naltrexone Hydrochloride (C20H23NO4-HCl), an opiate-antagonist prescribed for opiate drug addiction; it blocks the response to opiate drugs such as heroin or morphine. Doses for this usage are 50-150 mg.

So where did Low Dose Naltrexone (LDN) come from?
The idea of using Naltrexone at a much lower dosage for treating immune disorders such as MS is credited to Dr. Bernard Bihari, a practicing neurologist in New York, who began prescribing LDN for his MS patients in 1985.

How does Low Dose Naltrexone work?
LDN works by briefly* obstructing the effects of brain endorphins (the brain's natural painkillers). This has an effect of stimulating the increased production of these same endorphins, which re-balances the immune system, thus reducing the activity of the MS. This blocking effect lasts around 3 or 4 hours.

But how can this work? Isn’t MS is caused by an overactive immune system?
Although there is a long-held theory that MS might be caused by an overactive immune system, it has never been proven. Recent clinical studies indicate that this theory might not be true at all. The October 2004 issue of The Archives of Neurology reports a clinical study by researchers who found that intravenous immunoglobulin therapy applied after the first signs of MS significantly reduced the probability of developing clinically definitemultiple sclerosis. Patients receiving this immune-system boosting therapy also suffered fewer brain lesions.

What MS symptoms does LDN help?
Primarily neuromuscular spasm and fatigue, although patients have also reported improvements of numerous other symptoms. In addition, patients who are in the middle of an acute relapse when they start LDN have generally shown rapid resolution of the attack.

How fast does it work?
Around two-thirds of MS patients have some symptomatic improvement within the first few days.

What dosage and frequency should be prescribed?
The usual adult dosage of LDN for the treatment of MS is 4.5mg taken once daily at bedtime. Because of the rhythms of the body's hormone production, LDN is best taken between 9pm and 3am. The therapeutic dosage range for LDN is from 1.75mg to 4.5mg every night. Dosages below this range are likely to have no effect at all, and dosages above this range are likely to block endorphins for too long a period of time and interfere with its effectiveness.It is generally recommended that the patient begin on 4.5mg per day, and adjust the dosage if necessary. Prescribing 1.5mg capsules allows easy adjustment of dosage. (For example, the patient can take either 2 capsules for 3mg, or 3 capsules for a 4.5mg dose.)

How is LDN prepared?
LDN is prepared by a compounding pharmacy, who will make capsules by either grinding up 50mg tablets of Naltrexone, or using Naltrexone powder purchased from a primary manufacturer. The most popular source of Naltrexone is the 50mg "ReVia" Naltrexone tablet (DuPont), usually prescribed for treatment of drug and alcohol addictions. Naltrexone may also be taken as a solution (in distilled water) with 1mg per ml dispensed with a 5ml medicine dropper. If LDN is used in a liquid form, it is important to keep it refrigerated.
IMPORTANT: Make sure to specify that you do NOT want LDN in a slow-release form.

Are there any side effects?
All sources indicate that LDN has virtually no side effects. Occasionally, during the first week of use, patients may complain of difficulty sleeping. (Reports indicate that sleep disturbance is rare, occurring in less than 2% of users.) If this persists after the first week, dosage can be reduced from 4.5mg to 3mg. Full-dose Naltrexone (50mg 3x day) carries a cautionary warning for patients with liver disease. (This warning was placed because adverse liver effects were noted in early experiments involving 300mg daily.) The 50mg dose does not apparently produce impairment of liver function nor, of course, does the much smaller 3mg - 4.5mg dose. LDN, in the low doses used for MS therapy, is virtually non-toxic, simple to administer, and, compared with other MS drug therapy, very inexpensive.

What about cautionary warnings?
Because LDN blocks opioid receptors throughout the body for three or four hours, people using narcotic medication such as Ultram, morphine, Percocet, Tramadol, Duragesic patch or codeine should not take LDN until such medicine is completely out of the system. Steroids would counteract the effects of LDN, and so should not be combined. LDN should probably not be taken during pregnancy. LDN cannot be used by people already receiving beta interferon; because LDN stimulates the immune system and beta interferon suppresses it, the two therapies are incompatible.

What does it feel like to be on LDN?
At both high and low dosages, patients taking Naltrexone usually say they are largely unaware of being on medication. Naltrexone usually has no psychological effects and patients (at both high and low dosages) don't feel either "high" or "down" while they are on naltrexone. It is not addicting.

Why isn’t LDN routinely prescribed for MS?
Many physicians simply have not yet learned about the positive effects of LDN on MS symptoms. Others may be hesitant to prescribe LDN because it hasn’t yet been approved as an MS treatment by the FDA.

Why hasn’t LDN been approved by the FDA?
Although Naltrexone (in the higher 50mg dosage) was approved by the FDA in 1984, Low Dose Naltrexone (in the 3mg or 4.5mg dosage) has not yet been submitted for FDA approval. LDN cannot be officially approved by the FDA as an MS therapy until it undergoes specific clinical trials required by the FDA.

Why hasn’t LDN gone through a clinical trial as an MS therapy?
Clinical trials are usually initiated and funded by pharmaceutical companies, and these companies are not interested in promoting or marketing LDN.

Why aren’t pharmaceutical companies interested in exploring the possibility of LDN as an MS therapy?
Naltrexone was developed so long ago, no one holds a patent, so generic versions of the drug can be created and sold very inexpensively. LDN can't make anyone any money, so pharmaceutical companies are not willing to fund a clinical trial for a drug that will make them so little profit. Also, if LDN were certified by the FDA and became a preferred treatment for MS, the pharmaceutical companies who make the expensive ABCR (aka "crabs")drugs could lose million$ of dollar$. (In other words, it'$ all about the money.)

Are any clinical trials of LDN scheduled?
Responding to the rapidly-growing, patient-driven publicity about the success of LDN, the MS center at University of Texas recently announced plans for a full clinical trial of LDN as an MS therapy.

Are there any other plans to underwrite a clinical study of LDN and MS?
In August 2004, the LDN Research Trust was created in the UK. Conceived by a group of MS patients who have been helped by LDN, the Trust’s mission is to raise funds for the initiation of clinical trials for LDN. Their website,, encourages contributions and participation. In conjunction with the Trust, Dr Alasdair Coles, a neurologist and MS specialist from Cambridge University, and Dr Robert Lawrence of Wales, himself an MS patient, are currently working on a proposal for a clinical trial of LDN for the treatment of MS.

Has LDN been reported in any of the major medical journals?
Medical journals are not usually interested in reviewing any drug therapy that has not yet had a major clinical trial. However, the peer-reviewed medical journal Medical Hypothesis recently accepted an LDN/MS hypothesis for publication; it will be published in the next few months.

Can a doctor legally prescribe LDN?
Of course. While it is illegal for a pharmaceutical company to market or promote a drug for a use other than that approved by the FDA, it is NOT illegal for a physician to prescribe an FDA-approved drug for a non-FDA-approved use. (Neurontin, for example, was approved by the FDA in 1993 for the treatment of epilepsy; yet it is routinely prescribed for the "off-label" treatment of MS symptoms.) All physicians understand that the responsible off-label use of an already FDA-approved medication such as Naltrexone is perfectly ethical and legal.

How many MS patients are taking LDN for Multiple Sclerosis?
No one is sure of the exact number, but it is known that thousands of MS patients worldwide are now using LDN, and this number is growing. Without the financial support of the pharmaceutical industry, the reputation of LDN has been driven solely by the patients themselves.

Are MS patients getting positive results from LDN?
A review of the anecdotal evidence indicates that most MS patients taking LDN have experienced considerable improvement, often within days or weeks of beginning the treatment.

How can I obtain LDN and what will it cost?
Answer: LDN can be prescribed by your doctor, and prepared by a compounding pharmacy. Naltrexone is a prescription drug, so your physician would have to give you a prescription after deciding that LDN appears appropriate for you.Naltrexone in the large 50mg size, originally manufactured by DuPont under the brand name “ReVia”, is now sold by Mallinckrodt as “Depade” and by Barr Laboratories under the generic name “naltrexone”. LDN is now being made available by hundreds of local pharmacies, as well as by some mail-order pharmacies, around the US. Some pharmacists have been grinding up the 50mg tablets of naltrexone to prepare the 4.5mg capsules of LDN; others use naltrexone, purchased as a powder, from a primary manufacturer.One of the first pharmacies to do so was Irmat Pharmacy in Manhattan. Their recent price for a one-month's supply of 4.5mg LDN (30 capsules) was $38. Irmat will ship it anywhere, in the US or to other countries, and will accept prescriptions from any licensed physician.

Pharmacies that are good sources of LDN:
Irmat Pharmacy, New York, NY (212) 685-0500
The Compounder Pharmacy, Aurora, IL (800) 679-4667
The Medicine Shoppe, Canandaigua, NY (800) 396-9970
Skip's Pharmacy, Boca Raton, FL (800) 553-7429
Smith's Pharmacy, Toronto, Canada (800) 361-6624

IMPORTANT: Make sure to specify that you do NOT want LDN in a slow-release form.Reports have been received from patients that some pharmacies have been supplying a slow-release form of naltrexone. Pharmacies should be instructed NOT to provide LDN in an "SR" or slow-release or timed-release form. Unless the low dose of naltrexone is in an unaltered form, which permits it to reach a prompt "spike" in the blood stream, its therapeutic effects may be inhibited.

Also, make sure to fill your Rx at a compounding pharmacy that has a reputation for consistent reliability in the quality of the LDN it delivers. The FDA has found a significant error rate in compounded prescriptions produced at randomly selected pharmacies. Dr. Bihari has reported seeing adverse effects from this problem.


Jeffrey Dach MD said...

Narcan: FDA approved since 1984

Narcan, also called Naltrexone, has been FDA approved since 1984 for reversal of narcotics overdose. It reverses the sedating effect of opiates by binding to the opioid receptors in the brain. Narcan is available in the hospital operating room where anesthesiologists use it to wake up the patient after the operation. It was a surprise for me to find out that this commonly used drug has other very important uses at a much lower dosage as an oral capsule. Medical scientists have been carefully studying its effect on the immune system, and its clinical benefits for a host of disease states for the past 20 years.

Low Dose Naltrexone, (LDN), How Does it Work?

The beneficial effect of low dose naltrexone, LDN, was discovered by Bernard Bihari, MD, a physician in New York City who found that a small dose (3 mg) of naltrexone taken as a capsule at bedtime blocks the opiate receptors in the brain for a few hours during sleep, which then stimulates the brain to increase production of endorphins over the next 24 hours. These endorphins then stimulate the immune system. Although Bihari did much of the early clinical work, Zagon did much of the groundwork with animal research studies at Pennsylvania State University.

LDN Effective for Crohn's Disease

A recent publication in the Jan 2007 Journal of Gasteroenterology on the use of LDN in Crohn's Disease, was the first breakthrough publication to appear entitled,

Low-Dose Naltrexone Therapy Improves Active Crohn's Disease by Jill Smith MD.

For a more complete review with links to references, see my newsletter:

Low Dose Naltrexone LDN by Jeffrey Dach MD

Jeffrey Dach MD

Anonymous said...

My son is 32yrs old has ms he doctor won,t give him lDN. Why other drugs have teribb,e side effects Terrible I need to finda dr.who will prescibe it I live in Chicago,I'll any help

flora68 said...

To Anonymous: I found a few links for you, but some are VERY old and are bound to be outdated. I apologize for that. Hopefully someone can find, or help you find, a doc to prescribe LDN for your son. You already know by now that this search will take patience. Good luck:o)

"Although we do not keep lists of physicians who might be open to prescribing LDN, here are two websites that should be of assistance in finding such a doctor in your area: "

Once there, just choose your state in the Find An ACAM Physician chart.

Once there, click on Health Concerns at the top, then, on its page, click on Innovative Practitioners, and then on Innovative Doctors. Then choose your state or country.
Website editor --

P.S. - And, try asking the many members of the LDN-Yahoo Group.


Mr. Joseph Starkman
Phone number:

5248 N. Ashland Ave.

Chicago IL 60640
David Edelberg MD
Phone number:
(773) 296-6700
(773) 296-6700

2522 N. Lincoln Ave
Chicago IL 60614
Robert Brossard
Phone number:
(312) 951-2727
(708) 763-6261

1730 North Clark Street, APT 4005
Chicago IL 60614


Yaroslaw Bandura, MD
903 N. Western Ave.
Chicago, IL 60622
(773) 276-3573
Center for Integrated Health Care
111 North Wabash #1005
Chicago, IL 60602 4711
Phone #: 312-236-7010
Fax# 312-236-7190

Andrew Gorecki, L.AC.
The Alternative Medical Clinic
3207 N. Clark St.
Chicago, IL 60657
(773) 477-1702
Nicole King, MD
Internal Medicine, Chelation Therapy, Diet Nutrition, Insulin Potentiation, Neural Therapy, etc.
1525 E. 53rd. St. Suite 530
Chicago, IL 60615
(773) 667-0768

Razvan Rentea, MD
3525 W. Peterson #611
Chicago, IL 60659
(773) 583-7793
Paul Savage, MD
BodyLogicMD of Illinois
150 E Huron St, Suite 802
Chicago, IL 60611
(866) 535-2563
Specializes in bioidentical hormone therapy, nutrition and fitness for women and men.
Board Certified Anti-Aging, National Lecturer on hormone therapy

Zofia Stevanovic, MD
Internal medicine
3208 N. Major
Chicago, IL 60634
(773) 736-2772

Claude Williams, DC
Apollo Wellness Center
6262 N. Lincoln Ave.
Chicago, IL 60659
(773) 539-7400
David Zeiger, DO
healthWorks -Integrative Medicine Clinic
1030 N Clark Street, Suite 301
Chicago,IL 60610