In cancer research, scientists and clinicians continuously explore new treatments to improve patient outcomes. One emerging alternative therapy gaining attention is Low-Dose Naltrexone (LDN). Originally approved for opioid addiction at much higher doses, LDN is now being investigated for its potential role in cancer treatment. But does it work? Let’s dive into the science behind LDN and its possible benefits for cancer patients.
What is Low-Dose Naltrexone (LDN)?
Naltrexone was initially developed in the 1980s as a medication to block opioid receptors and treat addiction. The standard therapeutic dose for opioid addiction is 50mg to 100mg. However, researchers discovered that when administered at much lower doses (typically 1.5mg to 4.5mg), naltrexone had unexpected benefits for immune function and inflammation regulation. This lower dosing regimen is referred to as Low-Dose Naltrexone (LDN).
LDN is thought to work by temporarily blocking opioid receptors, which increases the production of endorphins and enkephalins—natural chemicals that regulate immune function, reduce inflammation, and may even have anticancer effects.
How LDN Might Help in Cancer Treatment
Cancer thrives in environments where the immune system is weakened or unable to recognize and attack tumor cells effectively. LDN has been hypothesized to exert its effects through several mechanisms:
Low-dose naltrexone (LDN) supports cancer treatment through several mechanisms, primarily involving the modulation of the immune system and the inhibition of cancer cell proliferation.
Immune Modulation:
LDN enhances the body's natural production of endorphins, which have been shown to regulate the immune response. Increased endorphin levels may help immune cells, such as natural killer (NK) cells and T-cells and M1-type macrophages, which are associated with anti-tumor activity. This shift in macrophage polarization enhances the immune response against cancer cells.[1]
Opioid Growth Factor Receptor (OGFr) Pathway: LDN intermittently blocks opioid receptors, leading to a compensatory increase in the synthesis of opioid growth factor (OGF) and its receptor (OGFr). This upregulation inhibits cancer cell proliferation and promotes apoptosis through the Bax/Bcl-2/caspase-3/PARP signaling pathway.[1-3]
 Gene Expression Modulation: LDN selectively impacts genes involved in cell cycle regulation and immune modulation, further contributing to its anti-cancer effects. This includes the upregulation of pro-apoptotic genes and the downregulation of anti-apoptotic mediators.[4]
InhibitsTumor Growth
Preliminary research suggests that LDN may help inhibit tumor cell proliferation. Some studies indicate that LDN interferes with signaling pathways that allow cancer cells to grow and spread, though more research is needed to confirm these findings.
Enhances Apoptosis (Cancer Cell Death)
Some studies suggest that LDN may promote apoptosis—the programmed death of cancer cells—by activating specific immune system pathways. This is crucial, as one of cancer’s key survival tactics is avoiding apoptosis.
Synergizes with Conventional Treatments
LDN is sometimes used alongside chemotherapy, radiation, and immunotherapy. Because of its potential to boost immune function and reduce the side effects of conventional treatments, some doctors and patients have explored its use in integrative cancer care. Pre-treatment with LDN can increase the sensitivity of cancer cells to drugs like oxaliplatin and cisplatin, leading to improved cell killing and reduced tumor growth.[4-5]
Potential Side Effects
LDN is generally well-tolerated, but some users report:
Mild sleep disturbances (especially in the first few weeks)
Vivid dreams
Digestive issues (nausea, stomach discomfort)
Because LDN interacts with opioid receptors, patients on opioid pain medications should not use it without medical supervision.
Should Cancer Patients Consider LDN?
If you’re interested in LDN as part of your cancer treatment plan, here’s what to consider:
Consult Your Doctor – Never start LDN without discussing it with your doctor first.
Use It as a Combination with other Therapies– LDN should not be used as a stand alone treatments.
Monitor Your Progress – Work with your healthcare team to track any benefits or side effects.
For now, LDN remains an experimental and off-label treatment. However, for those battling cancer, especially with limited treatment options, it may be worth exploring under medical supervision.
Low-Dose Naltrexone Inhibits Colorectal Cancer Progression and Promotes Apoptosis by Increasing M1-Type Macrophages and Activating the Bax/ÂBCL-2/ÂCaspase-3/ÂParp Pathway. Ma M, Wang X, Liu N, Shan F, Feng Y. International Immunopharmacology. 2020;83:106388. doi:10.1016/j.intimp.2020.106388.
Low-Dose Naltrexone as an Adjuvant in Combined Anticancer Therapy. Ciwun M, Tankiewicz-Kwedlo A, Pawlak D.Cancers. 2024;16(6):1240. doi:10.3390/cancers16061240.
The Effect of Low-Dose Naltrexone on Solid Ehrlich Carcinoma in Mice: The Role of OGFr, BCL2, and Immune Response. Aboalsoud A, El-Ghaiesh SH, Abd Elmonem FF, Salem ML, Abdel Rahman MN. International Immunopharmacology. 2020;78:106068. doi:10.1016/j.intimp.2019.106068.
Naltrexone at Low Doses Upregulates a Unique Gene Expression Not Seen With Normal Doses: Implications for Its Use in Cancer Therapy. Liu WM, Scott KA, Dennis JL, et al. International Journal of Oncology. 2016;49(2):793-802. doi:10.3892/ijo.2016.3567.
Low-Dose Naltrexone Suppresses Ovarian Cancer and Exhibits Enhanced Inhibition in Combination With Cisplatin. Donahue RN, McLaughlin PJ, Zagon IS. Experimental Biology and Medicine (Maywood, N.J.). 2011;236(7):883-95. doi:10.1258/ebm.2011.011096.
Disclaimer
This article is for educational purposes only and is not intended to provide medical advice, diagnosis, or treatment. Always consult with a qualified healthcare professional, such as a naturopathic physician or oncologist, before making changes to your diet, supplements, or lifestyle, especially if you have a medical condition or are undergoing cancer treatment.