Astragalus and Cancer: What the Research Shows

Astragalus, Astragalus membranaceus, known in Chinese as Huang Qi, is a root that has been used in Chinese medicine for more than 2,000 years to strengthen the body’s resistance to illness. In China it is one of the herbs most often given alongside chemotherapy, and in Taiwan an injectable astragalus extract is an approved prescription drug for cancer-related fatigue. This article explains how astragalus works, what the clinical evidence shows, and safety.

How Astragalus Works

Astragalus contains polysaccharides, saponins called astragalosides, and flavonoids. In laboratory and animal studies, its polysaccharides activate immune cells, including macrophages, natural killer cells and T cells, support the bone marrow during chemotherapy, and make chemotherapy, radiation and immunotherapy work better. A 2025 review of these animal studies found consistent added benefit when astragalus polysaccharides were combined with standard treatments.¹

Lung Cancer: The Largest Body of Evidence

A review published in the Journal of Clinical Oncology combined 34 randomized trials, mostly from China, including 2,815 patients with advanced non-small cell lung cancer receiving platinum chemotherapy. Adding astragalus-based herbal formulas reduced the risk of death at 12 months by about a third, improved tumor response, and reduced the side effects of chemotherapy.² The authors noted that many of the trials were of modest quality and used different formulas, so larger, well-designed trials are needed.

Taiwan: An Approved Astragalus Drug

In Taiwan, an injectable astragalus polysaccharide called PG2 is approved for cancer-related fatigue, based on double-blind, placebo-controlled trials in which it improved fatigue in people with advanced cancer.³ In a study of Taiwanese patients with advanced lung cancer receiving immunotherapy, PG2 normalized a blood marker of inflammation, the neutrophil-to-lymphocyte ratio, that predicts how well immunotherapy will work.⁴

Now Under Study

A double-blind, placebo-controlled trial that began in 2024 is testing astragalus in people with aggressive lymphoma receiving chemotherapy, to see whether it reduces side effects.⁵ See our article on lymphoma treatment.

Safety

Generally well tolerated. Side effects in trials have been uncommon and mild.

Immune effects. Because astragalus stimulates the immune system, it is used with caution by people taking drugs that suppress immunity, such as after an organ transplant, and by people with autoimmune disease. How it interacts with checkpoint immunotherapy has not been tested in randomized trials.

Quality. Herbal products vary widely. Products tested for purity, heavy metals and pesticides should be used. Astragalus is not used in pregnancy.

How Cancer Expert MD Helps

Cancer Expert MD provides education and consultation for people with every type and stage of cancer, and specializes in Stage IV and metastatic cancer. Our book, The New Reality of Cancer, covers astragalus and the other herbs and mushrooms from medical traditions around the world, with how each works, what studies in people show, the doses used, and drug interactions. See also our article on medicinal mushrooms.

Frequently Asked Questions

Can astragalus help chemotherapy work better?

In a review of 34 trials in advanced lung cancer, adding astragalus-based formulas to platinum chemotherapy reduced deaths at one year by about a third and reduced side effects, although the trials varied in quality.

Can astragalus help cancer fatigue?

Yes. In Taiwan, an injectable astragalus extract is an approved drug for cancer-related fatigue, based on placebo-controlled trials.

Is astragalus safe with immunotherapy?

It has not been tested in randomized trials with checkpoint immunotherapy. A Taiwanese study found it improved an inflammation marker linked to better immunotherapy results.

Who should not take astragalus?

People taking immune-suppressing drugs, such as after a transplant, people with autoimmune disease, and pregnant women.

About the author. Dr. Silver, MD, graduated from Temple University School of Medicine, trained as an interventional cardiologist, and has practiced medicine for nearly fifty years. A lymphoma survivor of about twenty-five years, he is co-author, with Dr. Lindmeier, DHSc, of The New Reality of Cancer: The Science of Recovery. Read more about Dr. Silver, MD.

Research by Dr. Lindmeier, DHSc, cancer educator and co-author of The New Reality of Cancer.

This article is for general education only and is not individual medical advice. Always consult your own doctor before making any changes to your care.

For more in-depth information on this topic and many others, get our book, The New Reality of Cancer: The Science of Recovery.

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References

Synergistic antitumor effects of astragalus polysaccharide: a preclinical systematic review and meta-analysis. Frontiers in Pharmacology. 2025;16:1672450.
McCulloch M, See C, Shu XJ, et al. Astragalus-based Chinese herbs and platinum-based chemotherapy for advanced non-small-cell lung cancer: meta-analysis of randomized trials. Journal of Clinical Oncology. 2006;24(3):419–430.
Chen HW, Lin IH, Chen YJ, et al. A novel infusible botanically-derived drug, PG2, for cancer-related fatigue: a phase II double-blind, randomized placebo-controlled study. Clinical and Investigative Medicine. 2012.
Astragalus polysaccharide injection (PG2) normalizes the neutrophil-to-lymphocyte ratio in patients with advanced lung cancer receiving immunotherapy. Integrative Cancer Therapies. 2021;20.
Efficacy and safety of astragalus for symptomatic alleviation in patients with high-grade lymphoma treated with chemotherapy: a double-blind randomized placebo-controlled trial. ClinicalTrials.gov NCT06510530. 2024.

This article is for education only. It is not medical advice and does not diagnose or treat any condition. Cancer Expert MD has no financial relationship with any laboratory, drug maker, supplement company, clinic or hospital.