Peptide Knowledge Base · Immune

Low-Dose Naltrexone (LDN): what it is, what the evidence says, and its real status

Not a peptide, a low dose of the approved drug naltrexone, used off-label for pain and autoimmune symptoms.

Can you actually get it?

Plain-English verdict: No availability record.

Regulatory status: No regulatory record.

How does Low-Dose Naltrexone (LDN) work?

At low doses, transient opioid-receptor blockade is proposed to modulate immune signaling and microglial activity.

What it does — and what it does not do

What it does: Studied for autoimmune-related symptoms, chronic pain, and inflammation.

What it does not do: Evidence is limited to small studies, it is not a peptide, and it is not offered on this surface.

How honest is the evidence?

Evidence grade C — Mixed / early human evidence.

small human studies in autoimmune/pain contexts; larger trials lacking

A grade measures how much human evidence exists, not whether a molecule is good, safe, or worth your interest. Read our grading methodology for what each grade means.

What we still don't know: Large randomized trials are lacking; effect sizes vary by condition.

WADA status: Not prohibited.

Who should not take it

Not for those on opioid therapy; clinician oversight for autoimmune contexts.

Sources

Low-dose naltrexone immune/pain pilot studies

Compounded medications are not FDA-approved. We keep two signals separate and never collapse them: whether you can get something, and what the rule currently says. See the live FDA Peptide Tracker for status.

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Last reviewed Jun 16, 2026 · Peptós.LIFE · Not medical advice.