Educational content only. Not medical advice, and no doctor-patient relationship is created. Read the medical disclaimer
Not a peptide · approved drug used off-label
Low-Dose Naltrexone (LDN)
Also known as: LDN
An older medicine used at a fraction of its usual dose, studied for pain and inflammation in conditions like fibromyalgia.
Tier 1 · Prescribe today
Grade C · Limited human evidence
Educational content only, not medical advice. Discussion here does not mean this therapy is prescribed by Youthful Medicine or available to you. Read the medical disclaimer
U.S. regulatory status
FDA-approved drug (naltrexone) used off-label at low doses. Prescription required.
What it is
Naltrexone is approved at standard doses for alcohol and opioid use disorders. “Low-dose” naltrexone is the same molecule used at a much smaller dose, off-label. It is not a peptide, but it is the practical answer to a gap in this quadrant.
How it is thought to work
At low doses it is thought to calm overactive immune cells in the nervous system (microglia, through a receptor called TLR4) and to cause a brief rebound in the body’s own endorphins.
Animations simplify biology for teaching. They are not a claim that this peptide works this way in people.
What the research shows
Small randomized trials and pilot studies suggest benefit in fibromyalgia and some inflammatory conditions. Larger and longer trials are still needed.
Safety and considerations
Usually well tolerated. Vivid dreams and sleep changes are the most common complaints. It blocks opioid pain medicines, which matters before surgery or if you take opioids.
Our position
Our practical first tool in this quadrant: lawful, inexpensive and reasonably safe, with honest expectations about the evidence.
Video lesson
AT A GLANCE
Quadrant
Autoimmunity & Inflammation
Tier
Tier 1 · Prescribe today
Evidence grade
Grade C · Limited human evidence
Last reviewed
Is this right for you?
Only a physician who has evaluated you can answer that. Consultations are with licensed Youthful Medicine providers.
Never use products labeled “research use only” or “not for human use.” Purity, dose and sterility are unverified.