Astragalus Plant Extract
Also known as: Astragalus, Huang Qi, Astragalus membranaceus
Overview
Astragalus membranaceus is a perennial plant native to China and Mongolia, widely used in Traditional Chinese Medicine (TCM). The extract, primarily derived from its root, is valued for its purported immunomodulatory, anti-inflammatory, antioxidant, and adaptogenic properties. It is commonly applied to support cancer patients, alleviate chronic fatigue, improve kidney function, and manage inflammatory conditions. While research maturity is moderate with a growing number of randomized controlled trials (RCTs) and meta-analyses, the methodological quality varies. Evidence is stronger for its adjunctive use in cancer and inflammatory diseases rather than as a standalone treatment.
Benefits
Astragalus membranaceus offers several evidence-based benefits, primarily as an adjunctive therapy. A 2025 systematic review and meta-analysis of 8 RCTs demonstrated a significant reduction in cancer-related fatigue (CRF), with a large effect size (SMD −1.63). For cancer patients undergoing chemotherapy, a meta-analysis of 1,409 colorectal cancer patients indicated that Astragalus combined with chemotherapy improved tumor response rate, quality of life, and reduced chemotherapy side effects. However, these studies had methodological limitations. In kidney function, a meta-analysis of 9 studies showed that Astragalus-containing Chinese herbal medicine, when combined with Western medicine, significantly lowered serum creatinine levels (SMD = 0.64), suggesting renal protective effects. Preclinical evidence from a systematic review and meta-analysis of animal studies on ulcerative colitis highlighted its anti-inflammatory and antioxidant effects, showing a reduction in inflammatory markers (TNF-α, IL-6, IL-1β) and oxidative stress markers (MDA), while increasing antioxidant enzyme activity (SOD).
How it works
Astragalus contains bioactive compounds such as polysaccharides, saponins, and flavonoids. These components modulate immune function by enhancing macrophage activity, stimulating cytokine production, and regulating T-cell function. Its anti-inflammatory effects are achieved by downregulating pro-inflammatory cytokines like TNF-α, IL-6, and IL-1β. Furthermore, it reduces oxidative stress by upregulating antioxidant enzymes such as superoxide dismutase (SOD). The polysaccharide fraction (APS) is considered a key bioactive component responsible for its immunomodulatory and anti-inflammatory activities. Oral bioavailability varies, with polysaccharides being partially absorbed and potentially acting via gut-associated lymphoid tissue.
Side effects
Astragalus extract is generally considered safe with a low incidence of adverse effects. Mild gastrointestinal discomfort may occur, though common side effects are not well-documented in high-quality studies. Uncommon (1-5%) and rare (<1%) side effects are not clearly reported. Caution is advised due to potential interactions with immunosuppressants, as Astragalus can stimulate immune function, and with anticoagulants, though specific mechanisms are not fully elucidated. It is contraindicated in individuals with autoimmune diseases where immune stimulation could be detrimental. Safety during pregnancy and lactation has not been well established, and its use in these populations is not recommended without medical supervision.
Dosage
Clinical studies typically utilize Astragalus doses ranging from 10 to 30 grams of dried root equivalent per day, or standardized extracts with defined polysaccharide content. The optimal dosage varies depending on the specific indication and the formulation used; for instance, injectable polysaccharide preparations are employed in some Chinese clinical settings. Administration is usually daily, and absorption may be enhanced when taken with meals. There is no well-established maximum safe dose, but clinical trials generally report good tolerability within the studied ranges, suggesting a favorable safety profile for short-to-medium term use.
FAQs
Is Astragalus effective alone or only as adjunct?
Evidence primarily supports Astragalus as an adjunctive therapy, especially when combined with chemotherapy or Western medicine, rather than as a standalone treatment.
How soon are effects seen?
Benefits, particularly on fatigue and inflammatory markers, may become apparent within a few weeks of consistent and regular use.
Is it safe long-term?
While short- to medium-term use appears safe in clinical trials, limited long-term safety data are available for Astragalus.
Does it interact with medications?
Possible interactions exist with immunosuppressants and anticoagulants. Always consult a healthcare provider before combining with medications.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11885490/ – This systematic review and meta-analysis of 9 RCTs found that Astragalus combined with Western medicine significantly reduced serum creatinine levels in patients with kidney impairment. Despite high heterogeneity, the robust sensitivity analysis supports renal protective effects, though more homogeneous studies are needed.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC6700271/ – This meta-analysis of 1,409 colorectal cancer patients indicated that Astragalus combined with chemotherapy improved tumor response rate, quality of life, and reduced chemotherapy side effects. However, the included RCTs had methodological limitations such as lack of blinding and allocation concealment, suggesting the need for higher quality trials.
- https://journals.sagepub.com/doi/10.1177/15347354241313344 – This systematic review and meta-analysis of 8 RCTs on cancer-related fatigue demonstrated a large reduction in fatigue (SMD=−1.63) with Astragalus. Despite the strong effect size, high heterogeneity and small sample sizes in the included studies reduce overall confidence in the findings, calling for larger, more rigorous trials.
- https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2022.1043236/full – This systematic review and meta-analysis of animal studies on ulcerative colitis showed that Astragalus polysaccharide (APS) significantly reduced inflammatory markers (TNF-α, IL-6, IL-1β) and oxidative stress markers (MDA), while increasing antioxidant enzyme activity (SOD). While providing strong preclinical evidence, the translational relevance to human conditions remains uncertain.
