Dextro-naltrexone

Dextro-naltrexone is a potential treatment proposed by Jarred Younger for chronic pain, fatigue, and cognitive disorders related to brain inflammation, theoretically with similar benefits to low dose naltrexone but without the harsh side effects which necessitate limiting the dose.

Theory

Dextro-naltrexone is the right-handed stereoisomer of the drug naltrexone. Stereoisomers are molecules that have the same chemical formula and atoms, but are mirror images of each other.

Like the levo- (left-handed) form of naltrexone used as low-dose naltrexone (LDN), which is currently one of the most effective yet still limited treatments for conditions like myalgic encephalomyelitis and fibromyalgia, dextro-naltrexone is theorized to cross the blood-brain barrier and calm activated microglia cells in the brain. Overactive microglia release inflammatory chemicals that contribute to symptoms like pain, fatigue, and cognitive impairment.

However, while levo-naltrexone (LDN) also acts as an opioid receptor antagonist, blocking the body's natural opioids and causing side effects like dysphoria and malaise, dextro-naltrexone is not expected to have this opioid-blocking effect. This key difference means dextro-naltrexone could potentially be dosed higher than LDN to achieve greater anti-inflammatory and symptom relief benefits, without being limited by the harsh side effects that restrict LDN dosing.

Evidence

As yet, dextro-naltrexone has never been used in humans. Younger and his lab hope to secure funding in late 2024 to subsequently pursue human safety and efficacy trials.

cognition Thought processes, including attention, reasoning, and memory.

adverse reaction Any unintended or unwanted response to a treatment, whether in a clinical trial or licensed treatment. May be minor or serious.

microglia A type of immune cell, called a macrophage, that lives in the brain. For historical reasons, macrophages have different names based on the part of the body that they normally live in. Macrophages that normally live in the blood are called monocytes. Macrophages that normally live in the skin are called Langerhans cells. Macrophages that normally live in the liver are called Kupffer cells. And macrophages that normally live in the central nervous system are called microglia. Microglia were originally classified as glial cells, under the assumption that the cells had a merely structural function, before it was realized that the cells were in fact immune cells. As the "sentinel cells" of the central nervous system, microglia survey their environment for abnormalities such as infection or tissue damage, and then initiate an immune response to fight the infection or repair the tissue damage.

antagonist A chemical that reduces or helps block the activity of another chemical in the body. For example, most antihistamines are H1 antagonists because they block the H1 histamine receptor, which helps relieve allergy symptoms. The opposite of an agonist.