Astragalus — Astragalus membranaceus

Common & Latin Names

Common names: Astragalus, Milk vetch, Yellow leader Latin name: Astragalus membranaceus (Fisch.) Bunge (syn. Astragalus propinquus) TCM name: Huang Qi (黄芪) — “Yellow Leader” (referring to the yellow color of the root and its leading role among Qi tonics)

Plant Family & Parts Used

Family: Fabaceae (legume family) Parts used: Root (harvested after 4-7 years of growth — older roots contain higher concentrations of active compounds). The root is sold in dried slices (flat, yellow, fibrous tongue-depressor-like pieces) for decoction. Habitat: Native to northern China, Mongolia, and Korea. Grows in grasslands and along forest margins at 800-2,000m elevation. Extensively cultivated in Shanxi, Inner Mongolia, and Heilongjiang provinces of China.

Traditional Uses

Traditional Chinese Medicine (2,000+ years)

Huang Qi is one of the most important and frequently prescribed herbs in TCM. It appears in the Shen Nong Ben Cao Jing as a superior herb. In classical TCM, Huang Qi is THE premier Qi tonic — it tonifies Spleen Qi, raises Yang Qi, stabilizes the exterior (Wei Qi — defensive energy), and promotes tissue regeneration.

Classical formulas featuring Huang Qi include:

• Bu Zhong Yi Qi Tang (Tonify the Middle and Augment Qi Decoction) — the master formula for Spleen Qi Deficiency with sinking Yang (prolapse, chronic fatigue, diarrhea)
• Yu Ping Feng San (Jade Wind Screen Powder) — the classic immune-support formula for frequent infections
• Shi Quan Da Bu Tang (Ten Complete Great Tonifying Decoction) — supreme Qi and Blood tonic
• Dang Gui Bu Xue Tang (Angelica Blood-Supplementing Decoction) — Huang Qi + Dang Gui in 5:1 ratio for blood deficiency

Classical indications: Spleen Qi deficiency (fatigue, poor appetite, loose stool), spontaneous sweating (Wei Qi weakness), chronic non-healing wounds and ulcers, edema, numbness and paralysis (post-stroke), and blood deficiency.

Modern Chinese Medicine

Astragalus is one of the most studied herbs in Chinese pharmaceutical research, particularly for immune enhancement in cancer patients (often given alongside chemotherapy), chronic hepatitis B, diabetic nephropathy, and cardiovascular disease.

Active Compounds & Pharmacology

Primary Phytochemicals

Astragalosides (triterpene saponins): Over 40 identified, with Astragaloside IV (AS-IV) being the most studied. AS-IV is the primary marker compound for standardization. It demonstrates cardioprotective, anti-fibrotic, anti-diabetic, anti-inflammatory, and telomerase-activating effects.

Astragalus polysaccharides (APS): High-molecular-weight heteropolysaccharides that are the primary immunomodulatory compounds. APS activate macrophages, dendritic cells, T-cells, and NK cells through TLR-4 and other pattern recognition receptors.

Flavonoids: Formononetin, calycosin, ononin — estrogenic, antioxidant, anti-inflammatory. Calycosin has neuroprotective and cardioprotective effects.

Amino acids: Including GABA, asparagine, and others.

Trace elements: Selenium, iron, zinc, copper, manganese — immunonutrient cofactors.

Mechanisms of Action

1. Immune Enhancement: APS activate innate immunity (macrophage phagocytosis, NK cell cytotoxicity, dendritic cell maturation) and adaptive immunity (T-cell proliferation, Th1 cytokine induction, antibody production). In TCM terms, this is “stabilizing the exterior” (Wei Qi) and “tonifying Zheng Qi” (upright/correct Qi that resists disease).

2. Telomerase Activation: Astragaloside IV and cycloastragenol (a metabolite) activate telomerase, the enzyme that maintains telomere length. Telomere shortening is associated with cellular aging and immune senescence. This mechanism provides a molecular basis for astragalus’s traditional reputation as a longevity herb. The commercial product TA-65 is a concentrated cycloastragenol extract marketed specifically for this purpose.

3. Cardioprotection: AS-IV protects cardiomyocytes from ischemia-reperfusion injury, reduces cardiac fibrosis, improves left ventricular function, and enhances angiogenesis in ischemic tissue. Mechanisms include PI3K/Akt pathway activation and antioxidant effects.

4. Anti-fibrotic (Kidney, Liver, Lung): AS-IV inhibits TGF-beta signaling and extracellular matrix deposition, reducing fibrosis in kidney (diabetic nephropathy), liver (hepatic fibrosis), and lung (pulmonary fibrosis).

5. Anti-diabetic: APS improves insulin sensitivity, reduces blood glucose, protects pancreatic beta cells, and reduces diabetic complications (nephropathy, neuropathy, retinopathy).

6. Adaptogenic / Qi Tonifying: Enhances physical and mental stamina, improves exercise capacity, and increases resistance to stress. This is the functional medicine correlate of “tonifying Spleen Qi.”

Clinical Evidence

Key Studies

Block, K.I., & Mead, M.N. (2003). “Immune system effects of echinacea, ginseng, and astragalus: a review.” Integrative Cancer Therapies, 2(3), 247-267.

• Comprehensive review of immunological evidence for three major immune herbs
• Astragalus section documented: enhanced NK cell activity, macrophage activation, T-cell proliferation, and cytokine modulation in both in vitro and in vivo studies
• Reviewed clinical evidence for immune support in cancer patients receiving chemotherapy — astragalus reduced immunosuppression and improved quality of life

Cho, W.C., & Leung, K.N. (2007). “In vitro and in vivo immunomodulating and immunorestorative effects of Astragalus membranaceus.” Journal of Ethnopharmacology, 113(1), 132-141.

• Demonstrated that APS restored suppressed immune function in immunocompromised mice
• Enhanced macrophage phagocytosis, lymphocyte proliferation, and NK cell activity
• Showed immunorestorative (not just immunostimulatory) effects — restoring suppressed immunity rather than simply pushing it higher

Luo, Y., Qin, Z., Hong, Z., et al. (2004). “Astragaloside IV protects against ischemic brain injury in a murine model of transient focal ischemia.” Neuroscience Letters, 363(3), 218-223.

• AS-IV demonstrated significant neuroprotection against stroke-induced brain injury
• Reduced infarct size and improved neurological function scores

Li, M., Wang, W., Xue, J., Gu, Y., & Lin, S. (2011). “Meta-analysis of the clinical value of Astragalus membranaceus in diabetic nephropathy.” Journal of Ethnopharmacology, 133(2), 412-419.

• Meta-analysis of 25 RCTs involving astragalus in diabetic nephropathy
• Results: Significant reductions in proteinuria, BUN, and serum creatinine compared to conventional treatment alone
• Concluded astragalus provides additional renal protection in diabetic patients

McCulloch, M., See, C., Shu, X.J., et al. (2006). “Astragalus-based Chinese herbs and platinum-based chemotherapy for advanced non-small-cell lung cancer.” Journal of Clinical Oncology, 24(3), 419-430.

• Meta-analysis of 34 RCTs (2,815 patients) of astragalus-containing formulas alongside platinum-based chemotherapy
• Results: Astragalus-based formulas increased treatment response rate (OR 1.34), reduced 1-year mortality (OR 0.67), reduced nausea/vomiting, and reduced leukopenia
• The largest meta-analysis supporting astragalus as a chemotherapy adjunct

Therapeutic Applications

Conditions

• Immune deficiency (frequent infections, poor wound healing, post-surgical recovery)
• Cancer adjunctive support (chemotherapy-induced immunosuppression)
• Chronic fatigue / Qi deficiency
• Diabetic nephropathy and complications
• Cardiovascular disease (adjunctive — cardioprotection)
• Chronic hepatitis B (immune support and hepatoprotection)
• Post-viral fatigue and recovery
• Allergies (Wei Qi stabilization)
• Longevity and anti-aging (telomerase activation)
• Post-stroke recovery (neuroprotection)

Dosage Ranges

• Dried root slices (decoction): 9-30g daily, simmered 20-30 minutes (standard TCM dose; up to 60-120g used in some Chinese hospital protocols for serious illness)
• Standardized extract (0.5-1% astragaloside IV): 500mg-2g daily
• Polysaccharide extract: 250-500mg, 2-3 times daily
• Tincture (1:5 in 30-40% alcohol): 3-5mL, 2-3 times daily
• Powder: 2-6g daily in capsules or mixed into food
• Culinary use: Astragalus slices are traditionally added to soups, broths, and congee (Chinese rice porridge) as food-medicine — removed before eating (the root is fibrous and not palatable to chew)

Safety & Contraindications

Very Safe

Astragalus is classified as a superior herb in TCM and has been consumed in food and medicine for over 2,000 years with an exceptional safety record. No significant toxicity reported in clinical trials.

Contraindications (TCM-Informed)

• Acute infection with fever and excess patterns: TCM contraindication — tonifying herbs should not be used during acute febrile illness as they may “feed the pathogen.” Wait until the acute phase resolves, then use astragalus for recovery.
• Yin deficiency with heat signs: Astragalus is warm and Qi-tonifying — in patients with Yin deficiency (night sweats, hot flashes, dry mouth, red tongue with no coating), it may worsen heat symptoms. Combine with Yin-nourishing herbs or avoid.
• Autoimmune conditions: Immune enhancement may theoretically exacerbate autoimmune diseases. However, clinical evidence is mixed — astragalus may actually modulate rather than simply stimulate immunity. Use with caution and monitoring.
• Pregnancy: Generally considered safe in food doses (culinary use in soups). Concentrated extracts lack safety data.
• Organ transplant: Immune enhancement may counteract anti-rejection medications.

Drug Interactions

• Immunosuppressants (cyclosporine, tacrolimus, corticosteroids): May counteract immunosuppressive effects.
• Lithium: Astragalus has diuretic properties — may alter lithium levels.
• Cyclophosphamide: Astragalus may both protect against toxicity and potentially reduce efficacy — complex interaction requiring oncologist guidance.
• Anticoagulants: Mild anticoagulant effects — monitor.

Energetics

TCM Classification

• Temperature: Slightly warm
• Flavor: Sweet
• Meridian entry: Spleen, Lung
• Actions: Tonifies Spleen Qi, raises Yang Qi, stabilizes the exterior and stops sweating (consolidates Wei Qi), promotes urination and reduces edema, promotes tissue regeneration and discharge of pus
• TCM pattern correspondence: Spleen Qi Deficiency (fatigue, poor appetite, loose stools, weakness), Wei Qi Deficiency (frequent colds, spontaneous sweating, weak immune function), Qi and Blood Deficiency (pallor, fatigue, weakness after illness or surgery).

Ayurvedic Classification (Modern Integration)

• Rasa: Madhura (sweet)
• Virya: Ushna (slightly warming)
• Vipaka: Madhura (sweet)
• Dosha effects: Reduces Vata. Tonifies all dhatus (tissues). Balances Kapha in moderation. May increase Pitta in excess.

Functional Medicine Integration

Immune Protocol (Preventive and Restorative)

Astragalus is the primary long-term immune-building herb in FM practice. Unlike echinacea (short-term, acute immune stimulation), astragalus is designed for sustained immune optimization over months to years. In the Yu Ping Feng San model (Jade Wind Screen), astragalus builds the “shield” that prevents pathogens from entering — this is preventive immune medicine.

Cancer Support Protocol

Extensive meta-analytic evidence (McCulloch 2006) supports astragalus alongside chemotherapy for improved response rates, reduced mortality, and reduced toxicity. It is among the most evidence-based herbal adjuncts in integrative oncology.

HPA Axis Protocol — Stage 3 Recovery

In Stage 3 HPA dysfunction, immune function collapses alongside cortisol. Astragalus addresses this immune component — rebuilding the Wei Qi (immune defense) that chronic stress has depleted. Combined with adrenal-specific herbs (rhodiola, eleuthero, ashwagandha) for comprehensive recovery.

Diabetic and Cardiometabolic Protocol

Renal protection (anti-fibrotic), blood sugar regulation, and cardiovascular protection position astragalus as a multi-target herb for metabolic disease.

Longevity Protocol

Telomerase activation provides one of the few mechanisms by which cellular aging might be slowed. While TA-65 (concentrated cycloastragenol) is commercially marketed for this purpose, whole astragalus root in traditional doses also provides telomerase-supporting compounds in the context of broader immune and metabolic benefits.

Four Directions Connection

Primary Direction: Serpent (South — Physical Body)

Astragalus is fundamentally the Serpent’s herb — the herb of physical resilience, immune defense, and the body’s capacity to protect itself. The Serpent sheds its skin and renews — astragalus promotes tissue regeneration and wound healing. The Serpent is instinct — the body’s ancient intelligence knowing what to attack, what to tolerate, what to ignore. The immune system IS this intelligence, and astragalus supports it at every level.

Secondary Direction: Hummingbird (North — Soul Journey)

Astragalus’s longevity associations — “Yellow Leader” that extends life, the telomerase activation, the 2,000-year tradition of life extension — resonate with the Hummingbird’s domain of the soul’s sustained journey through time.

Tertiary: Eagle (East — Wisdom)

In TCM, Qi clarity (the result of strong Spleen Qi) enables mental clarity. When Spleen Qi is deficient, thinking becomes foggy and sluggish. Astragalus, by tonifying Spleen Qi, indirectly supports the Eagle’s cognitive clarity.

References

1. Block, K.I., & Mead, M.N. (2003). Immune system effects of echinacea, ginseng, and astragalus. Integrative Cancer Therapies, 2(3), 247-267.

2. Cho, W.C., & Leung, K.N. (2007). In vitro and in vivo immunomodulating effects of Astragalus membranaceus. Journal of Ethnopharmacology, 113(1), 132-141.

3. McCulloch, M., et al. (2006). Astragalus-based Chinese herbs and platinum-based chemotherapy for advanced NSCLC. Journal of Clinical Oncology, 24(3), 419-430.

4. Li, M., et al. (2011). Meta-analysis of astragalus in diabetic nephropathy. Journal of Ethnopharmacology, 133(2), 412-419.

5. Luo, Y., et al. (2004). Astragaloside IV protects against ischemic brain injury. Neuroscience Letters, 363(3), 218-223.

6. Fu, J., Wang, Z., Huang, L., et al. (2014). Review of the botanical characteristics, phytochemistry, and pharmacology of Astragalus membranaceus. Phytotherapy Research, 28(9), 1275-1283.

7. Auyeung, K.K., Han, Q.B., & Ko, J.K. (2016). Astragalus membranaceus: A Review of its Protection Against Inflammation and Gastrointestinal Cancers. American Journal of Chinese Medicine, 44(1), 1-22.

8. Harley, C.B., Liu, W., Blasco, M., et al. (2011). A natural product telomerase activator as part of a health maintenance program. Rejuvenation Research, 14(1), 45-56.