Low-Dose Naltrexone Benefits

Low-dose naltrexone therapy is sometimes used to relieve pain and fatigue associated with fibromyalgia and chronic fatigue syndrome. Researchers are also looking at its effectiveness in treating multiple sclerosis, Crohn's disease, and long COVID.

Naltrexone is a medication that has been used to treat alcohol dependence and opioid-use disorder for more than 30 years. More recently, researchers found low doses of naltrexone—about 1/30th the standard dose—may be useful for other conditions.

This article discusses low-dose naltrexone benefits and uses related to fibromyalgia, chronic fatigue syndrome, and other conditions. It also explains the side effects of LDN therapy and what to avoid when taking naltrexone.

How Does Low-Dose Naltrexone Work?

At a normal dose of 50 to 100 milligrams (mg), naltrexone blocks the effects of opioid pain relievers and alcohol. It works by binding to opioid and endorphin receptors, preventing the feel-good molecules in alcohol and opioids from attaching.

Researchers are not entirely sure how lower doses of naltrexone work to relieve fibromyalgia, chronic fatigue syndrome, and potentially other conditions. Proposed pathways include:

• LDN blocks certain proteins that cause symptoms of fibromyalgia and chronic fatigue syndrome in the nervous system, which is the primary controlling and communicating system in the body.
• LDN works as an anti-inflammatory, which reduces inflammation or swelling in the nervous system.
• LDN may help keep the immune system, or what protects the body from harmful invaders, well-balanced, which may be why it tends to help people with immune system-related illnesses.
• LDN temporarily blocks receptors associated with pain and triggers the release of endorphins, the body's natural painkillers.
  

Low-Dose Naltrexone Uses

At very low doses, naltrexone may help people with fibromyalgia, chronic fatigue syndrome, and other conditions. Here is a closer look at low-dose naltrexone benefits and uses.

Fibromyalgia

Fibromyalgia is a chronic condition characterized by widespread pain, fatigue, sleep disturbance, cognitive impairment, depression, environmental sensitivities, and digestive symptoms.

A review of studies found that LDN could help reduce pain and improve quality of life in people with fibromyalgia, but it also noted that larger studies are needed to confirm the results.

LDN is not FDA-approved for fibromyalgia but is sometimes prescribed for off-label use.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is also known as myalgic encephalomyelitis. The condition involves deep fatigue, unrefreshing sleep, exercise intolerance, and neurological issues referred to as “brain fog.” Every person with chronic fatigue syndrome has a unique set of symptoms and degree of intensity.

LDN is sometimes prescribed off-label for chronic fatigue syndrome. There is growing evidence that some individuals have seen a reduction in their symptoms while using LDN.

Research suggests that individuals with chronic fatigue syndrome may have neuroinflammation, which is an inflammatory response in the brain or spinal cord. Because LDN may have an impact on inflammation in the nervous system, it's understandable why this may be a helpful treatment for some.

Multiple Sclerosis

Multiple sclerosis is an autoimmune condition where the body's immune system mistakenly attacks the protective covering of certain nerve cells. This can cause pain, muscle weakness, fatigue, and cognitive problems.

A few studies have found that LDN may be helpful in improving fatigue and quality of life in people with multiple sclerosis (MS). However, although clinical trials have established the safety and tolerability of LDN, it's difficult to draw any conclusions about efficacy because most of the studies have been small, poorly designed, or used animal models. More research could help confirm whether LDN is an effective treatment for MS. 

Long COVID

Around 38% of those with COVID-19 will continue to have symptoms for longer than 12 weeks. When this happens, it is called long COVID.

A few studies have looked at LDN as a treatment for patients with long COVID. One found that LDN is safe for people with long COVID, and that it could help reduce symptoms and improve well being. The study was small, however, and larger studies would be needed before it will be clear how LDN works in people with this condition.

Crohn's Disease

Crohn's disease is a chronic inflammatory condition that affects the tissues in your digestive tract.

Although LDN has been studied for its potential to reduce the severity of symptoms in people with Crohn's disease, most of the studies have been small and the outcomes were subjective, which means it's hard to know how much of an effect, if any, LDN has on the disease. It does appear to be safe and well-tolerated for people with Crohn's. 

Cancer

LDN has also been studied for its anticancer properties. However, studies that have found efficacy against certain cancers have largely been limited to animal models. Animal studies do not always translate well to human beings.

So far there isn't any research that supports the use of LDN in people with cancer, though the studies that do exist have been inconclusive. More research is needed before LDN can be recommended as a treatment for people with cancer.

Other Uses for Low-Dose Naltrexone

Research shows some promise for low-dose naltrexone in treating these other conditions:

• Alzheimer's disease
• Diabetic neuropathy
• Gulf War syndrome
• Parkinson's disease
• Autoimmune thyroid disorders
• Relapsing major depressive disorder

LDN Dosage

For use in treating fibromyalgia or chronic fatigue syndrome, naltrexone is generally given in doses of 4.5 mg or less. Typically, you'll start at 1.5 mg, work up to 3 mg, then increase to 4.5 mg.

Keep in mind that higher doses of naltrexone have not been shown to have the same symptom-reducing effects for fibromyalgia or chronic fatigue syndrome.

Research shows that the drug seems safe for long-term use. As long as naltrexone benefits you, you can take it on an ongoing basis.

Side Effects of Low-Dose Naltrexone

While LDN appears to be well-tolerated, known side effects of naltrexone include dizziness, headache, difficulty sleeping (insomnia), vivid dreams, nausea, vomiting, decreased appetite, joint pain, muscle cramps, tooth pain, and anxiety. Pain and swelling at the injection site may also occur if naltrexone is injected rather than taken as a pill.

Long-term side effects are uncommon with low-dose naltrexone. These tend to occur more often at higher doses. In rare instances, there can be severe side effects such as increased blood pressure or heart rate, confusion, depression, and allergic reactions. Contact your healthcare provider right away if you experience any of these.

People with kidney disease or liver disease may need to speak with their doctor before starting LDN. Those who are pregnant or breastfeeding should also speak with their doctor before starting this medication.

Interactions

You should avoid alcohol and certain other drugs when taking low-dose naltrexone.

Because low-dose naltrexone blocks opioid receptors, it's important not to take this medication with opioid pain relievers such as Ultram (tramadol) and OxyContin (oxycodone). Doing so may cause opioid withdrawal symptoms. 

Cytochrome P450 (CYP450) is a protein that helps your body metabolize drugs. Because naltrexone can inhibit these enzymes, it should not be taken with CYP450 substrate medications such as:

• Norvasc (amlodipine)
• BuSpar (buspirone)
• Valium (diazepam)
• Erythrocin (erythromycin)
• Viagra (sildenafil)
• Coumadin (R-warfarin)
• Mellaril (thioridazine)
• Certain chemotherapy drugs
  

Summary

Researchers aren't sure exactly how LDN works when it comes to conditions like fibromyalgia and chronic fatigue syndrome. Some believe it may act as an anti-inflammatory agent, help balance the immune system, or trigger the release of endorphins.

In research and case studies, LDN has been shown to help decrease symptoms with minimal side effects. However, most of these studies have been small and more research is needed.