Naltrexone (LDN)

Capsule

1.5 mg | 3 mg | 4.5 mg

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Disclaimer: Images are for reference only; actual products may vary.

Product Overview Coming Soon

Product Overview

Product Description

Naltrexone (LDN) Description^1-5

Low Dose Naltrexone (LDN) refers to naltrexone hydrochloride administered in doses ranging from 0.5 mg to 4.5 mg, which is substantially lower than the standard 50–100 mg doses used for opioid or alcohol dependence. At these lower doses, naltrexone may have immunomodulatory and anti-inflammatory effects and can be compounded into capsules.

Under the supervision of a healthcare provider, LDN may be considered as an adjunct for conditions such as:

Autoimmune diseases (e.g., multiple sclerosis, Hashimoto’s thyroiditis, rheumatoid arthritis)
Chronic pain syndromes (e.g., fibromyalgia, complex regional pain syndrome)
Inflammatory disorders (e.g., Crohn’s disease)

References

Younger J, Noor N, McCue R, Mackey S. “Low-dose naltrexone for the treatment of fibromyalgia: findings of a small, randomized, double-blind, placebo-controlled, counterbalanced, crossover trial.” Arthritis Rheum. 2013;65(2):529-538. https://pubmed.ncbi.nlm.nih.gov/23359310/
Smith JP, Stock H, et al.“Low-dose naltrexone therapy improves active Crohn’s disease.”Am J Gastroenterol. 2007;102(4):820–828. https://pubmed.ncbi.nlm.nih.gov/17222320/
Brown N, Panksepp J.“Low-dose naltrexone for disease prevention and quality of life.”Med Hypotheses. 2009;72(3):333–337. https://pubmed.ncbi.nlm.nih.gov/19041189/
LDN Research Trust (non-profit organization with compiled clinical data and patient reports): accessed August 2025 through: https://www.ldnresearchtrust.org
U.S. National Library of Medicine – DailyMed (Naltrexone HCl official monograph) accessed August 2025 through: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=06ff2d5a-e62b-4fa4-bbdb-01938535bc65

Product Mechanism of Action

Mechanism of Action^1-5

There are several potential pathways that may explain the activity of low-dose naltrexone, although further studies are needed to fully understand the mechanism of action. The following are potential pathways of activity:

Opioid Receptor Modulation

LDN may temporarily block opioid receptors (especially μ-opioid receptors) for a few hours.

This transient blockade can lead to a rebound increase in endogenous endorphins and enkephalins when the drug is cleared.

Higher levels of endorphins may enhance immune system regulation and reduce pain perception.

Toll-Like Receptor 4 (TLR4) Antagonism

Naltrexone acts as a non-specific antagonist of TLR4, found on microglia in the CNS.

By inhibiting TLR4, LDN reduces the release of pro-inflammatory cytokines (e.g., TNF-α, IL-6).

This may help to reduce neuroinflammation, often implicated in chronic pain and autoimmune disorders.

Immunomodulation

LDN is thought to restore T-regulatory cell function and normalize Th1/Th2 balance, critical in autoimmune disease regulation.

May inhibit abnormal B-cell activity and reduce autoantibody production.

Product Adverse Reactions

Common^1-5

Vivid dreams or insomnia (often resolves after 1–2 weeks)
Headache
Nausea
Fatigue
Anxiety or restlessness

Product Contraindications & Precautions

Contraindications^1-5

Current opioid use: LDN may precipitate opioid withdrawal and block opioid analgesia.
Known hypersensitivity to naltrexone hydrochloride or its excipients.

Precautions^1-5

Liver disease: Though rare at low doses, monitor liver function if using long term or in patients with hepatic impairment.
Autoimmune flare risk: Temporary symptom worsening may occur during immune modulation.
Use caution in:
Patients with major depressive disorder (monitor mood)
Pregnant or lactating individuals (safety not well established)

Product Storage

Store at controlled room temperature (20°C to 25°C / 68°F to 77°F)
Protect from moisture and light
Keep in a tightly closed container

Product References

Younger J, Noor N, McCue R, Mackey S. “Low-dose naltrexone for the treatment of fibromyalgia: findings of a small, randomized, double-blind, placebo-controlled, counterbalanced, crossover trial.” Arthritis Rheum. 2013;65(2):529-538. https://pubmed.ncbi.nlm.nih.gov/23359310/
Smith JP, Stock H, et al.“Low-dose naltrexone therapy improves active Crohn’s disease.”Am J Gastroenterol. 2007;102(4):820–828. https://pubmed.ncbi.nlm.nih.gov/17222320/
Brown N, Panksepp J.“Low-dose naltrexone for disease prevention and quality of life.”Med Hypotheses. 2009;72(3):333–337. https://pubmed.ncbi.nlm.nih.gov/19041189/
LDN Research Trust (non-profit organization with compiled clinical data and patient reports): accessed August 2025 through: https://www.ldnresearchtrust.org
U.S. National Library of Medicine – DailyMed (Naltrexone HCl official monograph) accessed August 2025 through: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=06ff2d5a-e62b-4fa4-bbdb-01938535bc65

Product Disclaimer

This information is for educational purposes only.

This compounded product has not been reviewed, approved, or evaluated by the Food and Drug Administration for safety and effectiveness. This product is not intended to diagnose, treat, cure, or prevent any disease. No claims are made regarding treatment, cure, or prevention of any disease or condition.

This information is a summary. It may not cover all possible drug information about this product. For complete product information, refer to the manufacturer’s prescribing information and labeling. Call your doctor for medical advice and/or about side effects. You may report side effects to the FDA at 1-800-FDA-1088. A WP Pharma Labs pharmacist will be happy to answer any questions. For consultation, please call 1-800-441-0048.

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