OnePin Peptide Library · Immune
Low-Dose Naltrexone (LDN)
LDN · Naltrexone Low-Dose
Low-dose naltrexone (LDN) refers to the use of naltrexone at doses of 0.5-4.5mg, which is roughly 1/10th of the standard 50mg dose used for opioid and alcohol addiction. At these low doses, naltrexone exhibits fundamentally different pharmacological properties - rather than sustained opioid receptor blockade, it produces a brief, transient blockade that triggers a compensatory upregulation of endogenous opioid production (endorphins, met-enkephalin) and opioid receptor sensitivity.,LDN has gained significant attention in integrative and functional medicine for autoimmune conditions, chronic pain, inflammatory disorders, and cancer. The hypothesized mechanism involves modulation of the innate immune system through Toll-like receptor 4 (TLR4) antagonism on microglia and macrophages, reducing neuroinflammation and systemic inflammation. This anti-inflammatory effect is distinct from its opioid receptor activity.,Despite growing clinical use and positive case series, LDN remains largely off-label with limited large-scale RCT data. The most studied conditions include multiple sclerosis, fibromyalgia, Crohn's disease, and complex regional pain syndrome. LDN is available from compounding pharmacies and is generally well-tolerated with minimal side effects.
Take at bedtime (9-10 PM). Start at 0.5-1mg and increase by 0.5-1mg every 1-2 weeks until reaching target of 3-4.5mg. Some practitioners recommend morning dosing if vivid dreams are problematic.
Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.
How it works
At low doses (0.5-4.5mg), naltrexone produces a brief (4-6 hour) blockade of opioid receptors, after which the body compensates by upregulating production of endorphins (beta-endorphin) and met-enkephalin. This 'rebound' effect results in higher baseline endogenous opioid levels over 18-20 hours of each 24-hour cycle. Endorphins have immunomodulatory effects, promoting NK cell activity and balancing T-helper cell responses.,LDN antagonizes Toll-like receptor 4 (TLR4) on microglia and macrophages, which is a pattern recognition receptor in the innate immune system. TLR4 blockade reduces microglial activation and the production of pro-inflammatory cytokines (TNF-alpha, IL-6, IL-1beta, NF-kB signaling). This mechanism is independent of opioid receptor effects and may be the primary driver of benefits in autoimmune and neuroinflammatory conditions.,The net effect is a shift from a pro-inflammatory to a regulatory immune state - reduced autoimmune attack, decreased neuroinflammation, and improved immune surveillance. This dual mechanism (endorphin upregulation + TLR4 antagonism) explains LDN's broad applicability across seemingly unrelated conditions.
At low doses (0.5-4.5mg), naltrexone produces a brief (4-6 hour) blockade of opioid receptors, after which the body compensates by upregulating production of endorphins (beta-endorphin) and met-enkephalin. This 'rebound' effect results in higher baseline endogenous opioid levels over 18-20 hours of each 24-hour cycle. Endorphins have immunomodulatory effects, promoting NK cell activity and balancing T-helper cell responses.,LDN antagonizes Toll-like receptor 4 (TLR4) on microglia and macrophages, which is a pattern recognition receptor in the innate immune system. TLR4 blockade reduces microglial activation and the production of pro-inflammatory cytokines (TNF-alpha, IL-6, IL-1beta, NF-kB signaling). This mechanism is independent of opioid receptor effects and may be the primary driver of benefits in autoimmune and neuroinflammatory conditions.,The net effect is a shift from a pro-inflammatory to a regulatory immune state - reduced autoimmune attack, decreased neuroinflammation, and improved immune surveillance. This dual mechanism (endorphin upregulation + TLR4 antagonism) explains LDN's broad applicability across seemingly unrelated conditions.
What to expect
Weeks 1-4: Titration phase. Vivid dreams common. Subtle mood and energy changes possible.
Evidence
Interactions & stacking
What's safe to combine, and what belongs in a separate pin.
Safe & synergistic
Keep separate
Pharmacokinetics
Storage. Store compounded capsules or liquid at room temperature (20-25C) or refrigerate for longer stability. Compounded liquid formulations may have shorter shelf life (90 days typical). Keep away from light and moisture.
Regulatory status
Naltrexone is FDA-approved at 50mg for opioid and alcohol use disorders (ReVia, Vivitrol). Low-dose naltrexone (0.5-4.5mg) is entirely off-label. Available only from compounding pharmacies in the US - not commercially manufactured at LDN doses. No DEA scheduling (not a controlled substance). Prescription required.
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The guide & community
The complete Low-Dose Naltrexone (LDN) walkthrough, real protocol discussion and coaching live inside the BlessUp community on Skool.
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