The Lowdown on LDN

The Lowdown on LDN

Julian Whitaker, MD

Low-dose naltrexone is an inexpensive drug that is showing great promise in the treatment of everything from fibromyalgia and allergies to autoimmune disorders and cancer.

How can one drug have so many positive effects? It all has to do with the endorphin system. Endorphins are naturally occurring molecules that are similar in structure to morphine and other opioid drugs. Although endorphins are best known for boosting mood and blunting pain, they are active in almost every cell in the body. One endorphin, opioid growth factor (OGF), which regulates the immune system, is the target of LDN.

LDN binds to OGF receptors, which temporarily blocks OGF utilization. Due to the perceived shortage of OGF, there is a rebound effect where cells dramatically increase production of OGF and receptor sensitivity. Once the drug is excreted—and this only takes a couple of hours since the dose is so low—the OGF receptors are able to utilize all the extra OGF circulating in the blood.This has profound effects on several aspects of immune function. It puts the brakes on undifferentiated growth of cancer cells. It also prevents immune system overactivity, which is the crux of autoimmune disorders, and blunts the release of inflammatory and neurotoxic chemicals in the brain. Medical conditions marked by immune dysfunction are associated with markedly low levels of OGF, and LDN simply restores these disease-fighting endorphins to optimal levels.

A World of Possibilities

Ian Zagon, PhD, of Penn State, is the scientist who discovered the LDN-opioid link way back in 1979, and he’s the driving force behind most of the research on both OGF and LDN. OGF has actually been synthesized, but because it cannot be absorbed when taken orally, it must be administered by injection. Nearly 100 studies have examined OGF and its role in cancer and other conditions. This endorphin has been found to regulate cell proliferation in the most common types of cancer, inhibit tumor growth, and increase survival.

Although OGF is not available in the US at this time, LDN is widely available. All it requires is a prescription from a doctor—but there’s the rub. Naltrexone (brand name Revia), which is sold in drugstores in 50 mg tablets, is approved for alcohol, heroin, and other opioid drug withdrawal. Ask your doc for a prescription for 3 mg to boost your immune function, and he’ll likely think you’re crazy. No drug company is promoting an unpatented drug that costs $20–$30 per month. None of them even manufacture it. LDN has to be made to order from a compounding pharmacy.

Although it’s perfectly legal to prescribe an FDA-approved drug for off-label use, many docs are reluctant to do so. We’ve had patients come to California from all over the country because their physicians refused to prescribe this safe, inexpensive drug.


  • The suggested dose is 3–4.5 mg per day, taken at bedtime. The only contraindication is narcotic drugs. LDN blocks their effects and could cause withdrawal symptoms, so it should be started only after those drugs are completely out of your system. LDN is safe and well tolerated. Some people report vivid dreams at first, but in my clinical experience, sleep disturbances are rare. To avoid this, start with a dose of 1.5 mg and build up slowly over two months.
  • LDN requires a prescription and is available only from compounding pharmacies such as Gideon’s Drugs (212) 575-6868, Skip’s Pharmacy, (800) 553-7429, and McGuff Compounding Pharmacy, (877) 444-1133. If your doctor refuses to write a prescription, consider coming to the Whitaker Wellness Institute. For more information, call (866) 944-8253.
  • To learn more about LDN, also visit lowdosenaltrexone.org or simply surf the Internet. This will give you a feel for the tremendous patient enthusiasm for LDN.


  • Brown N, et al. Low-dose naltrexone for disease prevention and quality of life. Med Hypotheses. 2009 Mar;72(3):333–337.

Modified from Health & Healing with permission from Healthy Directions, LLC. Photocopying, reproduction, or quotation strictly prohibited without written permission from the publisher. To subscribe to Health & Healingclick here.

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