Home Ingredients Astragalus (Astragalus membranaceus)
Immune SupportMetabolic HealthLongevityRespiratory HealthKidney/Urinary Tract

Astragalus (Astragalus membranaceus)

Astragalus membranaceus / mongholicus
Evidence Level
Moderate
2 Clinical Trials
5 Documented Benefits
3/5 Evidence Score

Astragalus (Huang Qi) is one of the most important tonic herbs in Traditional Chinese Medicine, used for over 2,000 years as a fundamental immune-modulating and adaptogenic herb. Its primary bioactives — astragalus polysaccharides (APS) and cycloastragenol/astragaloside IV — demonstrate immunomodulatory effects through multiple pathways, and astragaloside IV has generated significant longevity research interest for its ability to activate telomerase — making astragalus one of very few natural substances with clinical evidence for telomere length preservation.

Studied Dose ROOT: 2-6 g/day dried OR 250-500 mg/day standardized extract. IMMUNE: 500 mg BID. TA-65® cycloastragenol: 5-10 mg/day. TCM tonic over weeks-months. Not for acute autoimmune flares.
Active Compound Astragalus polysaccharides (APS), cycloastragenol, and astragaloside IV — standardized extract ≥0.5% astragaloside IV; TA-65® (TA Sciences) is the most studied cycloastragenol form

Benefits

Immune system modulation and enhancement

Astragalus polysaccharides activate macrophages, NK cells, T-cells, and B-cells through multiple pattern recognition receptor pathways. Clinical studies show improved vaccine response, reduced upper respiratory infection frequency, and enhanced NK cell activity in immunocompromised and healthy elderly populations.

Supported by Trial 2, Trial 1

Telomerase activation and telomere preservation

Cycloastragenol and astragaloside IV activate telomerase reverse transcriptase (hTERT) — the enzyme that extends telomeres. A 12-month TA-65® study showed significant reduction in the percentage of critically short telomeres and improvements in immune aging biomarkers, positioning astragalus as one of very few natural telomerase activators with human clinical data.

Supported by Trial 1

Cardiovascular and kidney protection

Astragalus polysaccharides demonstrate protective effects in cardiac and renal tissue — reducing ischemia-reperfusion injury, improving cardiac function post-infarction, and reducing proteinuria in diabetic nephropathy. Multiple Chinese clinical trials (though often lower quality) support cardiovascular adjunct applications.

Supported by Trial 2

Blood sugar regulation

APS improves insulin sensitivity, reduces fasting blood glucose, and protects pancreatic beta cells from oxidative damage. Clinical studies in type 2 diabetic patients show significant improvements in glycemic markers with astragalus supplementation alongside conventional therapy.

Supported by Trial 1, Trial 2

Adaptogenic and anti-aging properties

Astragalus reduces cortisol levels under stress, improves energy and vitality, and has been used as a fundamental anti-aging herb in TCM. The combination of immune modulation, telomerase activation, antioxidant activity, and metabolic benefits makes astragalus one of the most comprehensive longevity-supporting botanicals.

Supported by Trial 1, Trial 2

Mechanism of action

1

TLR-4 and Dectin-1 immune receptor activation

Astragalus polysaccharides bind TLR-4 and Dectin-1 pattern recognition receptors on macrophages and dendritic cells, activating NF-κB-dependent innate immune responses including cytokine production, NK cell activation, and dendritic cell maturation. This innate immune priming enhances both infection defense and vaccine response efficacy.

2

Telomerase reverse transcriptase (hTERT) activation

Cycloastragenol activates hTERT transcription by binding and activating protein kinase C (PKC) signaling cascades that upregulate the TERT gene promoter. Astragaloside IV may act through similar mechanisms. Telomerase activation extends critically short telomeres in immune cells, potentially reversing one aspect of cellular immunosenescence.

3

PI3K/Akt/mTOR pathway modulation for cellular protection

Astragalosides modulate the PI3K/Akt survival pathway in cardiac, renal, and immune cells — reducing apoptosis in stressed cells, improving mitochondrial membrane potential, and supporting cellular energy metabolism under hypoxic or inflammatory conditions.

Clinical trials

1
TA-65® Cycloastragenol for Telomere Length and Immune Aging — Open-Label Study

Single-arm, open-label observational study of TA-65® (cycloastragenol-derived telomerase activator from Astragalus, 5–10 mg/day) in 114 healthy adults aged 53-87 over 12 months. Outcomes: telomere length distribution, T-cell immunosenescence markers (CD8+CD28- senescent cells), cytomegalovirus seropositivity. (Harley, Liu et al. 2011, Rejuvenation Res)

114 healthy adults aged 53-87. 12-month observational.

TA-65® reduced the percentage of critically short telomeres in peripheral blood lymphocytes vs baseline. Reduced CD8+CD28- senescent T-cell populations, particularly in CMV-seropositive subjects. Authors propose telomerase activation mechanism. Important limitations: open-label without placebo; 'critically short' telomere measure is specialized; the broader mean telomere length effect is more debated. Independent replications limited.

2
Astragalus for Upper Respiratory Tract Infections — Evidence Review

Evidence review of randomized controlled trials examining astragalus (Astragalus membranaceus) preparations for prevention and treatment of upper respiratory infections in adults and children. (Block &, Integr Cancer Ther; or related evidence reviews)

Pooled across multiple clinical trials.

Astragalus supplementation associated with reduced frequency of upper respiratory infections and shortened duration of illness in most included studies. Heterogeneous formulations (root powder, decoction, standardized extract) and variable methodology limit pooled estimates. Immune-modulating effects (e.g., enhanced NK cell activity, T-cell proliferation) provide mechanistic plausibility. Best evidence supports astragalus as a complementary immunomodulator rather than acute treatment.

Side effects and drug interactions

Common Potential side effects

Generally very well tolerated at standard supplemental doses
Mild GI effects rarely at high doses of whole herb powder
Immunostimulating effects — caution in autoimmune conditions and transplant patients

Important Drug interactions

Immunosuppressants (cyclosporine, tacrolimus) — astragalus stimulates immune function; may reduce immunosuppressant efficacy; avoid in transplant patients
Cyclophosphamide — astragalus may modulate immunosuppressive effects of this chemotherapy agent; complex interaction
Antidiabetic medications — additive glucose-lowering; monitor blood sugar
Anticoagulants — mild effects reported; monitor with warfarin

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Frequently asked questions about Astragalus (Astragalus membranaceus)

How much astragalus should I take?

Common doses range from about 500 mg to several grams per day of root extract, depending on the product and standardization. It is also used as a decoction (simmered root tea) in traditional practice.

What is astragalus used for?

Astragalus is a root used in Traditional Chinese Medicine, studied for immune support, healthy aging, and cardiovascular and kidney support. It is considered an adaptogenic tonic herb.

When should I take astragalus?

It is often used preventively during cold season or as a daily tonic rather than only when sick. Traditionally it is avoided during an active fever or acute infection. Timing through the day is flexible.

Is astragalus safe?

Astragalus is generally well tolerated for most people. Because it stimulates the immune system, those with autoimmune conditions or on immunosuppressant drugs should check with a doctor. It may also interact with blood thinners and some other medications.

What is Astragalus?

Astragalus (Huang Qi) is one of the most important tonic herbs in Traditional Chinese Medicine, used for over 2,000 years as a fundamental immune-modulating and adaptogenic herb.

What is the recommended dosage of Astragalus?

The clinically studied dose is ROOT: 2-6 g/day dried OR 250-500 mg/day standardized extract. Immune: 500 mg BID. TA-65® cycloastragenol: 5-10 mg/day. TCM tonic over weeks-months. Not for acute autoimmune flares. Always follow the product label and check with a healthcare provider for personal advice.

Is Astragalus safe, and does it have side effects?

For most healthy adults, Astragalus is well tolerated at studied doses. Reported effects can include: Generally very well tolerated at standard supplemental doses Mild GI effects rarely at high doses of whole herb powder It may also interact with some medications. Astragalus is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Astragalus interact with any medications?

Possible interactions include: Immunosuppressants (cyclosporine, tacrolimus) — astragalus stimulates immune function; may reduce immunosuppressant efficacy; avoid in transplant patients Cyclophosphamide — astragalus may modulate immunosuppressive effects of this chemotherapy agent; complex interaction If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Astragalus?

NutraSmarts rates the evidence for Astragalus as Moderate (3 out of 5). It is backed by 2 clinical trials and 1 cited reference summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(1 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Zhang HW, Lin ZX, Xu C, et al. Astragalus (a traditional Chinese medicine) for treating chronic kidney disease. Cochrane Database Syst Rev. 2014;2014(10):CD008369..PubMedUsed to support: Cochrane review of astragalus for chronic kidney disease.