Isoprinosine Update: Immunovir - A Promising, Low Cost and Safe Prescription Antiviral

Published: August 6, 2012

By Alina Garcia MD, Fibromyalgia and Fatigue Center, Las Vegas

Recent findings presented at the 2009 International Association of Chronic Fatigue conference in Reno, Nevada, by University of Miami researchers revealed promising potential for Isoprinosine (ISP) in addressing Chronic Fatigue Immune Deficiency Syndrome. Sixty one patients were studied, and therapy in all patients resulted in clinical and immunologic improvement. Isoprinosine (ISP), a non-toxic immune system stimulant, is a nucleoside, which is a basic compound comprising cells. It is extremely safe and has been available in Ireland and Canada for 20 years. Until now ISP has not been extensively utilized in the U.S. Although the University of Miami study was small, and larger placebo controlled studies are necessary, these preliminary findings are quite promising for sufferers of this relentless condition.

ISP has been studied extensively in AIDS research and Sub Acute Sclerosing Pan Encephalitis (SSPE). Researchers in Brazil have published results that ISP may even inhibit replication of viral RNA. Latent viruses are often associated with chronic fatigue and fibromyalgia.

ISP has shown promise in addressing CFIDS specifically via its immune modulating functions. Cheney, et al, has shown that ISP enhances Natural Killer (NK) cell function which is known to be suppressed in many CFIDS and FM patients.

I have been using Isoprinosine in selected patients for several years with favorable clinical outcomes in the majority of cases. ISP is more cost effective than other immune modulators and may therefore be a more viable option for some patients. The Fibromyalgia and Fatigue Centers Inc. are dedicated to addressing chronic fatigue and fibromyalgia using an integrated comprehensive approach.

Medication Background: Isoprinosine/Immunovir


Newport Pharmaceuticals


Antiviral and Immune modulation. May see better response in those patients with decreased NK cell activity and/or high RNAse-L.


The active ingredient is Methisoprinol (Inosine Pranobex). Isoprinosine have both immunomodulating and antiviral properties and helps to address acute and chronic viral infections.

Recommended Dosage

The prescribed dosage is one 500 mg cap twice a day Monday through Friday with none on the weekend. The following week the dose is 3 caps twice daily Monday through Friday with none on the weekend. Then, none the following week. Then repeat the cycle — Staying on for two months and off one.


Very safe and approved in most countries except the U.S. (but it can still be shipped to the U.S.). There can be a temporary rise in uric acid (so be careful if you have gout). However, uric acid is low in most CFS patients and acts as an antioxidant, so this may actually be beneficial.


Can be obtained on an individual basis for patients from Canada. Fax the prescription and order form to Rivex Pharma at Fax number (800) 784-0976.

Prescription should read:

Isoprinosine/Immunovir 500 mg
Sig: as directed
# bottles, and refills
ICD-9 780.71 Dx: CFS
On special request for personal import only

Note: The cost is $205 for a bottle of 100 plus $20 for shipping. With above dosing, patients will use 1 and 1/3 bottle (130 caps) every 3 months.

Jacob Teitelbaum, MD

is one of the world's leading integrative medical authorities on fibromyalgia and chronic fatigue. He is the lead author of eight research studies on their effective treatments, and has published numerous health & wellness books, including the bestseller on fibromyalgia From Fatigued to Fantastic! and The Fatigue and Fibromyalgia Solution. His newest book (June 10, 2024) is You Can Heal From Long COVID. Dr. Teitelbaum is one of the most frequently quoted fibromyalgia experts in the world and appears often as a guest on news and talk shows nationwide including Good Morning America, The Dr. Oz Show, Oprah & Friends, CNN, and Fox News Health.

e-mail icon
Facebook icon
Twitter icon
Google icon
LinkedIn icon