Does Naltrexone (low dose, LDN) work?

Read Off Label rates the evidence for Naltrexone (low dose, LDN) as Weak and the benefit magnitude as low, producing an overall grade of C+ (5.3/10). Not really a weight loss drug in isolation; part of Contrave combo.

Is Naltrexone (low dose, LDN) safe?

Naltrexone (low dose, LDN) has a low risk profile in published human data. Legal status: Rx (off-label; compounded). This is not medical advice — see the disclaimer.

Rankings / Metabolic Health

Naltrexone (low dose, LDN)

Metabolic Health · Opioid antagonist

Tier C+

Reviewed by Read Off Label · Last reviewed Jun 7, 2026 · How we grade

opioidprescription

5.3 / 10

Tier C+

Ev 3 Bn 2 Sf 9

Bottom line

Read Off Label grades Naltrexone (low dose, LDN) as C+ (5.3/10) based on weak evidence, low benefit magnitude, and a low-risk safety profile.

Not really a weight loss drug in isolation; part of Contrave combo.

Typical use: 1. — Rx.

What this is

Not really a weight loss drug in isolation; part of Contrave combo. LDN has legitimate off-label uses for fibromyalgia and autoimmune conditions but weight loss claims are thin. Widely used in biohacker/alt-med circles.

Mechanism

At low doses (1.5-4.5 mg): transient mu-opioid blockade triggers rebound endorphin release; modulates immune/microglial function; TLR4 antagonism

Dose & route

1.5-4.5 mg PO at bedtime

Citations

Links go to the source. If a link is dead or you want something re-checked, let me know.

Common questions

Does Naltrexone (low dose, LDN) work?: Read Off Label rates the evidence for Naltrexone (low dose, LDN) as Weak and the benefit magnitude as low, producing an overall grade of C+ (5.3/10). Not really a weight loss drug in isolation; part of Contrave combo.
Is Naltrexone (low dose, LDN) safe?: Naltrexone (low dose, LDN) has a low risk profile in published human data. Legal status: Rx (off-label; compounded). This is not medical advice — see the disclaimer.
What is the typical dose for Naltrexone (low dose, LDN)?: 1.5-4.5 mg PO at bedtime
How does Naltrexone (low dose, LDN) work?: At low doses (1.5-4.5 mg): transient mu-opioid blockade triggers rebound endorphin release; modulates immune/microglial function; TLR4 antagonism

This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.