Low Dose Naltrexone (LDN): A Promising Adjunct in Cancer Care

This low-cost medication is gaining attention in integrative oncology

As we recognize October as Breast Cancer Awareness Month, it's an opportune time to explore and discuss emerging therapeutic approaches that are showing promise in supportive cancer care.

It's important to note that LDN is currently being explored in integrative oncology as a supportive adjunct therapy, but it is not yet part of standard oncology care, and larger clinical trials are still needed to establish its role.

Among these is Low Dose Naltrexone (LDN), a repurposed medication that has captured the attention of integrative oncology practitioners and researchers worldwide. While conventional cancer treatments remain the cornerstone of care, LDN is gaining recognition as a potential adjunct therapy that may enhance treatment outcomes and support the immune system during the complicated and stressful cancer journey.

From Addiction Treatment to Cancer Support

Naltrexone received approval from the United States Food and Drug Administration (FDA) in the 1980s as an opioid antagonist for the treatment of alcohol and opioid addiction at standard doses of 50 mg or higher. Recent research indicates that at substantially lower doses, typically between 1.5 mg and 4.5 mg daily, naltrexone demonstrates distinct biological effects that may offer therapeutic benefits for individuals with cancer.

This distinction is significant. At standard doses, naltrexone continuously blocks opioid receptors. In contrast, at low doses, it induces a brief and transient blockade, which triggers a compensatory physiological response. This response results in immune-modulating and anti-cancer effects that are not observed with higher doses.

How LDN Works: Multiple Mechanisms

Research has identified several mechanisms by which low-dose naltrexone (LDN) may influence cancer progression:

Targeting the OGF-OGFr Pathway

Numerous cancer cell types, including those from breast, ovarian, colorectal, and lung cancers, exhibit increased expression of opioid growth factor receptors (OGFr). Temporary blockade of these receptors by low-dose naltrexone (LDN) stimulates increased production of opioid growth factor (OGF), an endogenous peptide that inhibits cancer cell proliferation. This process alters cell cycle regulation and may slow tumor growth.

Immune System Enhancement

Low-dose naltrexone (LDN) enhances the immune response against cancer cells by increasing natural killer cell activity and modulating cytokine production. LDN promotes a shift toward an immune profile that is more effective in targeting cancer cells and reduces chronic inflammation, which is a recognized contributor to cancer development and progression.

Direct Anti-Cancer Effects

Studies indicate that low-dose naltrexone (LDN) can modulate cancer cell signaling pathways, thereby affecting cellular proliferation, survival, and apoptosis. Research further demonstrates that LDN increases the expression of pro-apoptotic proteins, which enhances the susceptibility of cancer cells to chemotherapeutic agents.

The Research Evidence

Laboratory Studies

Extensive research utilizing cell cultures and animal models provides evidence for the anti-cancer potential of low-dose naltrexone (LDN). Studies demonstrate that LDN inhibits the growth of various cancer cell lines and slows tumor progression in animal models. Notably, LDN exhibits synergistic effects with conventional treatments; when combined with chemotherapy agents such as cisplatin or paclitaxel, it produces greater anti-tumor effects than chemotherapy alone.

Clinical Observations

Although large-scale clinical trials remain necessary, smaller studies and case reports have documented positive outcomes. These reports describe extended survival times and disease stabilization in patients with advanced cancers when low-dose naltrexone (LDN) is included in integrative treatment protocols.

A recent case series evaluating low-dose naltrexone (LDN) for cancer-related pain in 20 patients, 45% of whom had breast cancer, reported an 80% positive response rate. These findings underscore both the favorable safety profile of LDN and its potential value in comprehensive cancer care.

Focus on Breast Cancer

During Breast Cancer Awareness Month, it is particularly relevant to examine the potential role of low-dose naltrexone (LDN) in breast cancer care. Breast cancer cells, especially hormone receptor-positive subtypes, frequently exhibit increased expression of opioid receptors and the OGF-OGFr axis, making them potentially responsive to LDN therapy.

Preclinical studies indicate that low-dose naltrexone (LDN) inhibits breast cancer cell proliferation, reduces metastatic potential, and enhances the efficacy of standard treatments. Laboratory research also demonstrates synergistic effects when LDN is combined with tamoxifen and aromatase inhibitors.

Clinical observations from integrative oncology practices suggest that breast cancer patients receiving low-dose naltrexone (LDN) may experience improved quality of life, increased tolerance of conventional treatments, and, in some cases, favorable disease outcomes.

Safety Profile

A notable characteristic of low-dose naltrexone (LDN) is its favorable safety profile. Across multiple studies, LDN has been consistently well-tolerated and associated with minimal side effects:

• Transient vivid dreams or sleep disturbances (typically resolving within weeks)

• Mild gastrointestinal symptoms

• Occasional headaches

• Rare mood changes

Side effects are generally mild and frequently resolve with dose adjustment. However, several important considerations should be noted:

• LDN should not be used with opioid pain medications

• Discontinue 48 hours before surgery, where opioids may be needed

• Discuss potential drug interactions with healthcare providers

LDN as an Adjunct Therapy

Low-dose naltrexone (LDN) is not a standalone cancer treatment or a substitute for standard oncology care. Instead, LDN is being investigated as an adjunct therapy that may:

• Enhance immune system function against cancer cells

• Reduce cancer-promoting inflammation

• Improve tolerance to chemotherapy and radiation

• Support quality of life during treatment

• Potentially enhance conventional therapy effectiveness

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Patients considering low-dose naltrexone (LDN) should consult with their oncology team to determine its appropriateness for their individual clinical circumstances.

The Compounding Pharmacy Advantage

Standard naltrexone tablets are available in a 50 mg strength, which exceeds the 1.5 to 4.5 mg doses typically used in low-dose naltrexone (LDN) protocols. Specialized compounding pharmacies are essential for preparing these lower-dose formulations.

Compounding pharmacies prepare customized low-dose naltrexone (LDN) formulations tailored to individual patient requirements:

• Precise low-dose formulations (0.5 mg to 4.5 mg)

• Various delivery forms (capsules, sublingual tablets, topical preparations)

• Flexibility to adjust doses based on individual response

• Quality assurance for accurate dosing and purity

• Collaboration with prescribing physicians

Cottonwood Compounding collaborates directly with healthcare providers and patients to prepare high-quality low-dose naltrexone (LDN) formulations using pharmaceutical-grade ingredients, thereby ensuring personalized care for each patient's specific needs.

Looking Forward

The body of research supporting the potential role of low-dose naltrexone (LDN) in cancer care is expanding. Although current evidence is promising, larger clinical trials are required to establish optimal dosing protocols, identify patient subgroups most likely to benefit, and evaluate long-term safety and efficacy.

Several clinical trials are currently underway, examining low-dose naltrexone (LDN) in various types of cancer. These studies are expected to provide more definitive evidence regarding the role of LDN in contemporary cancer care.

Take the Next Step

During Breast Cancer Awareness Month, low-dose naltrexone (LDN) exemplifies the potential of repurposing existing medications to support patients throughout cancer treatment. Although not a curative agent, LDN shows promise as a component of comprehensive, integrative cancer care.

If you're interested in learning more about Low Dose Naltrexone, overall:

1. Discuss LDN with your oncologist or primary care physician

2. Consult with an integrative oncology specialist experienced with LDN

3. Contact Cottonwood Compounding to learn about customized formulations

At Cottonwood Compounding, we're committed to supporting patients and healthcare providers with high-quality compounded medications. We collaborate directly with prescribers to provide truly personalized pharmaceutical care.

References

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Memorial Sloan Kettering Cancer Center. Low-dose naltrexone. Integrative Medicine. 2025.

Murugan S, Rousseau B, Sarkar DK. Beta 2 Adrenergic Receptor Antagonist Propranolol and Opioidergic Receptor Antagonist Naltrexone Produce Synergistic Effects on Breast Cancer Growth Prevention. Cancers. 2021;13(19):4858.

National Cancer Institute, Office of Cancer Complementary and Alternative Medicine. The State of the Science of Alpha-Lipoic Acid plus Low-Dose Naltrexone for the Treatment of Cancer. 2012.

Qu N, Meng Y, Handley MK, Wang C, Shan F. Preclinical and clinical studies into the bioactivity of low-dose naltrexone (LDN) for oncotherapy. International Immunopharmacology. 2021;96:107714.