Astragalus

Astragalus (Astragalus membranaceus): A Comprehensive Reference

1. Identity and Botanical Description

Taxonomic Identity

Astragalus, known as Huangqi in Chinese, is the dried root of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao or Astragalus membranaceus (Fisch.) Bge., which belongs to the Leguminosae (Fabaceae) family. Though there are over 2,000 species of astragalus, only two are primarily used in supplements — Astragalus membranaceus and Astragalus mongholicus. The plant is also referred to in official pharmacopeial literature as Astragali Radix and Radix Astragali.

Astragalus membranaceus is a sun-loving perennial in the Fabaceae family native to China, Mongolia, and North Korea. It is an herbaceous perennial, growing between 25 and 40 centimeters in height, growing in grassy regions and on mountainsides, requiring plenty of exposure to the sun. The plant mainly grows in Inner Mongolia, Shanxi, Gansu, and Heilongjiang provinces of China.

Astragalus membranaceus belongs to the legume family (Fabaceae) and produces a thick, yellow taproot that has been harvested for medicinal purposes since the Han Dynasty (206 BCE – 220 CE). Astragalus is traditionally harvested when the plant is at least four or five years old or older, with the roots collected in the spring and fall.

Common Names

Astragalus is also known as huáng qí or milkvetch, and is most commonly known for its use in traditional Chinese medicine. Its Chinese name Huang Qi means "Big Yellow" and refers to the herb's connection to the Earth Element, which rules the Spleen and Stomach in Five Element Theory in Oriental medicine. In other traditions it is known as ogi (Japanese), hwanggi (Korean), and kibana-ogi.

Astragaloside IV (AS-IV) is used as the main marker for the quality control of Astragalus membranaceus in the Chinese Pharmacopeia (2020 version).

Common Preparations and Forms

Astragalus is considered an adaptogen, which is a natural substance theorized to stimulate the body's resistance to physical, environmental, and emotional stress. Sometimes combined with other herbs, astragalus has been promoted as a dietary supplement for many conditions, including upper respiratory infections, allergic rhinitis (hay fever), asthma, chronic fatigue syndrome, chronic kidney disease, and diabetes.

Astragalus is commercially available in several dosage forms, including:

• Dried root slices (for decoction, soups, and broths)
• Encapsulated powders and standardized root extracts
• Fluid extracts and tinctures
• Injectable preparations (used clinically in China)
• Granules (e.g., Astragalus granule formulations used in hospital settings)
• Topical preparations promoted for wound healing

The roots are energetically sweet and warming by nature. Often, they are sold in thin slices or cooked into traditional soups, broths, and stir-fry dishes. The root has a mild aroma and a slightly sweet taste. When chewed, it produces a faint beany flavor.

2. Traditional and Historical Use

Traditional Chinese Medicine

Astragalus membranaceus (Huangqi) is a major medicinal herb that has been commonly used in many herbal formulations in the practice of traditional Chinese medicine (TCM) to treat a wide variety of diseases and body disorders, or marketed as life-prolonging extracts for human use in China, for more than 2000 years.

Astragalus, or Huang Qi, is one of the fifty fundamental herbs in Traditional Chinese Medicine. Revered as a top herb, this powerful plant was first mentioned in Shennong Bencaojing (The Divine Husbandman's Classic of Materia Medica) over 2,000 years ago. In this foundational text, Astragalus was classified as a superior tonic — one of the herbs designated for long-term use to build vitality rather than treat acute symptoms.

TCM practitioners describe it as sweet in flavor and slightly warm in nature, entering the Spleen and Lung meridians. In TCM, it is used to strengthen wei qi, which is the protective layer that helps the body manage challenges from the external world. In ancient China, Astragalus membranaceus was termed "Sacred medicine with the effects of tonifying Qi and consolidating exterior."

Astragalus membranaceus has been used as a herbal medicine for more than two thousand years, having the effects of tonifying Qi and consolidating exterior, inducing diuresis to alleviate edema, expelling toxins and draining pus, promoting granulation, improving the body's immunologic function, protecting the liver, increasing secretion of urine, anti-aging, anti-stress, lowering blood pressure, and relatively broad-spectrum antibiosis.

In Traditional Chinese Medicine, Astragalus is said to tonify the "spleen" and hence is used for fatigue linked to decreased appetite. In traditional medicine, Astragalus is usually mixed with other herbal products and applied for therapeutic purposes.

Astragalus sp. has traditionally had a long history of use since ancient times, mainly by boiling the dried roots of the plant and mixing its extracts with honey. When used in soups, the root's sweet taste lends flavor and health benefits to help tonify the whole body.

Use in Other Cultures

Astragalus has been used in Traditional Chinese Medicine and Persian medicine for thousands of years. The recorded history of the plant dates back at least to the 1st century CE, and the genus was well-known to Western European botanists of the 17th century. The medicinal properties of Astragalus species were known to European botanists in the 1700s.

Members of the Lakota tribe, among Native American peoples, have been documented chewing the root to relieve back pain and cough. Lakota women consumed Astragalus roots to increase breast milk production. In addition, Astragalus roots were used in steam from boiling for the treatment of respiratory diseases.

Astragalus is a traditional Chinese herbal medicine used as a general tonic and treatment for many conditions including diarrhea, upper respiratory infections, heart disease, hepatitis, and cancer.

3. Key Constituents and Active Compounds

Overview of Phytochemical Classes

The major components of Astragalus membranaceus are polysaccharides, flavonoids, and saponins. Astragali radix contains a wide range of active compounds, including polysaccharides (e.g., astragalans and APS), saponins (e.g., astragalosides and cycloastragenol), flavonoids (e.g., calycosin and isosaponarin), alkaloids (e.g., betaine and choline), amino acids, and essential trace elements (e.g., tryptophan, GABA, zinc, iron, and copper).

Astragalus contains a wide array of constituents including more than 40 saponins, several flavonoids including isoflavones, polysaccharides, free-form amino acids, essential fatty acids, coumarins, and multiple trace minerals.

The root of Astragalus contains substantial amounts of coumarin, folic acid, choline, betaine, linoleic acid, linolenic acid, vanillic acid, ferulic acid, isoferulic acid, palmitic acid, hydroxyphenylacrylic acid, caffeic acid, palmic acid, β-sitosterol, daucosterol, lupeol, and numerous other compounds.

Of the 20 identified amino acids, asparagine, canavanine, proline, arginine, aspartic acid, and alanine are the most abundant.

Saponins (Astragalosides)

Astragalosides, important tetracyclic triterpenoid compounds, are considered to be the main active constituents in A. membranaceus, of which cycloastragenol-type glycosides are the most typically bioactive compounds with pharmacological activities. Most A. membranaceus saponins possess a cycloartane-type triterpenoid skeleton named cycloastragenol, modified by glucosylation at the C3/C6/C25-OH and/or xylosylation at C3-OH.

Astragaloside IV (AS-IV) has achieved the most attention among the A. membranaceus saponins. Most A. membranaceus saponins possess a cycloartane-type triterpenoid skeleton named cycloastragenol. AS-IV has been documented as one of the main active ingredients of A. membranaceus and is used as the main marker for quality control in the Chinese Pharmacopeia (2020 version).

Cycloastragenol (CAG) is another bioactive molecule derived from various species of the Astragalus genus. It is an aglycone derivative of AS-IV and a triterpenoid saponin compound formed through the hydrolysis of AS-IV.

Flavonoids

Among the flavonoids, isoflavones are the major constituents, and calycosin-7-O-β-D-glucoside, as one of the isoflavones, is the dominant component, and is used as a chemical marker in quality analyses. Astragalosides I–IV, trigonosides I–III, formononetin, ononin, calycosin, saponins, and triterpenoids are among the major components isolated from the Astragalus plant.

Polysaccharides

Astragalus polysaccharide (APS) is a water-soluble, chemically complex heteropolysaccharide that comprises portions of heteropolysaccharides, glucans, and both neutral and acidic polysaccharides. Pharmacologically recognized bioactive compounds include astragaloside IV, cycloastragenol, calycosin, formononetin, quercetin, and polysaccharides such as β-(1→3)-D-glucan.

4. Established Mechanisms of Action

Immunomodulation

The main bioactive compounds including flavonoids, triterpene saponins, and polysaccharides obtained from A. membranaceus have shown a wide range of biological activities and pharmacological effects, with a significant role in protecting the liver, immunomodulation, anticancer, antidiabetic, antiviral, anti-inflammatory, antioxidant, and anti-cardiovascular activities.

Astragalus polysaccharide (APS) can regulate the anti-programmed cell death protein 1 (PD-1)/PD-L1 on the surface of the immune cells, as part of the immune checkpoint inhibitory signaling pathway, by activating the immune-suppressed microenvironment through regulating cytokines, toll-like receptor 4 (TLR4), nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) pathways, and immune cells such as dendritic cells, macrophages, and NK cells.

Anti-inflammatory Pathways

Astragaloside IV (AS-IV) and Astragalus polysaccharides (APS) exert potent anti-inflammatory effects primarily by inhibiting the NF-κB signaling pathway. This inhibition results in a decrease in the production of key pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6. Furthermore, these bioactive compounds suppress the activation of the NLRP3 inflammasome, a critical complex that drives the maturation and secretion of IL-1β, thereby mitigating a central inflammatory cascade in central nervous system disorders.

Telomerase Activation

Cycloastragenol (CAG) is a sapogenin of Astragaloside IV, isolated from the dried roots of Astragalus mongolica or Astragalus membranaceus. Cycloastragenol has a steroidal skeleton of tetracyclic triterpene and possesses diverse pharmacological activities such as anti-aging, anti-inflammatory, anti-fibrosis, pro-wound healing, liver protection, and endothelial protection. In addition, cycloastragenol is the only telomerase activator reported in natural products, which is closely related to MAPK and PI3K/Akt signaling pathways.

Astragalus contains active compounds such as astragaloside IV and cycloastragenol, which have been identified as potent telomerase activators. These compounds can compensate for replicative telomere erosion by activating telomerase, a specialized reverse transcriptase that uses a specific template RNA to extend the 3′ strand of chromosome ends.

Antioxidant Activity

The mechanism of action of astragalus is primarily involved in antioxidant protection, anti-inflammatory effects, and anti-apoptotic properties. Clinical studies have shown that Astragalus can improve kidney function, reduce proteinuria, increase serum superoxide dismutase, decrease lipid peroxidation, decrease endothelin-1, and regulate cellular immunity in patients with moderate to severe chronic kidney disease.

Anticancer Mechanisms (Preclinical)

Preclinical studies indicate that APS exerts significant anti-liver cancer effects through multiple biological actions, including the promotion of apoptosis, inhibition of proliferation, suppression of epithelial-mesenchymal transition, regulation of autophagy, and modulation of immune responses. These therapeutic effects are closely associated with the regulation of critical signaling pathways, such as PI3K/AKT/mTOR, Wnt/β-catenin, JAK/STAT, and TGF-β/Smad.

APS also reshapes the tumor microenvironment by enhancing macrophage activity, reducing regulatory T cell function, and improving the host immune response.

Neuroprotection

Components of A. membranaceus preserve blood-brain barrier (BBB) integrity through several concerted actions. Astragalus polysaccharides (APS) inhibit the transcription factor ETS1, thereby blocking Endothelial-to-Mesenchymal Transition (EndoMT) and helping to stabilize tight junctions.

Cardiovascular Mechanisms

Astragalus membranaceus and its bioactive constituents, including astragaloside IV, cycloastragenol, and the commercial telomerase activator TA-65, demonstrate significant promise in attenuating vascular aging and atherosclerotic disease. These compounds exert a range of pleiotropic effects, including anti-inflammatory, antioxidant, endothelial-protective, and lipid-modulating actions, while also modulating telomerase activity and supporting telomere maintenance.

5. Scientific Evidence by Area of Use

5.1 Immune Function

A systematic review and meta-analysis published in 2023 evaluated the effect of Astragalus on humoral and cellular immune response in human studies. A comprehensive search of electronic databases was conducted identifying relevant studies published up to April 2023. Studies that assessed the impact of Astragalus on humoral and cellular immune markers were included, and a random-effects meta-analysis was performed to determine the overall effect size. Subgroup analyses were conducted based on outcome measures. A total of 19 studies, including 1,094 human participants, were included in the meta-analysis.

This meta-analysis found that astragalus demonstrated significant reductions in proinflammatory cytokines (SMD: −2.8765, 95% CI −3.2385 to −2.5145) and an enhancement of cellular immune markers (SMD: 2.4629, 95% CI 1.9598 to 2.9661), but that there was substantial heterogeneity across the studies. Astragalus was associated with a reduction in the pro-inflammatory cytokines IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ.

Evidence strength: The pooled effect sizes are statistically significant, but the substantial heterogeneity across the 19 included studies limits the generalizability of conclusions. Many studies were conducted in Chinese clinical settings, often in diseased populations rather than healthy volunteers.

5.2 Chronic Kidney Disease and Nephropathy

A 2023 review of 50 studies involving 3,423 participants showed that adding astragalus to supportive care or immunosuppressive therapy for treating the kidney disorder membranous nephropathy resulted in greater improvements in some indicators of kidney health. The authors of the review cited several problems with the studies, including their low quality, small size, and limited geographical location.

A number of clinical studies have shown that Astragalus can improve kidney function, reduce proteinuria, increase serum superoxide dismutase, decrease lipid peroxidation, decrease endothelin-1, and regulate cellular immunity in patients with moderate to severe CKD. Pharmacological studies have also demonstrated that Astragalus may offer immunomodulatory, anti-inflammatory, and renoprotective effects. It may also ameliorate renal interstitial fibrosis and inhibit glomerular mesangial cell proliferation and interleukin-6 secretion.

A 2025 systematic review and meta-analysis of 14 randomized controlled trials involving 800 patients assessed Astragalus-containing Chinese herbal medicine used alongside Western medicine for lupus nephritis. The analysis included 14 RCTs, with a total of 800 patients (417 in the treatment group and 383 in the control group).

Evidence strength: Promising but constrained. Available trials are predominantly from China, are of generally low methodological quality, small in size, and often use astragalus as part of multi-herb formulas, making it difficult to isolate its individual contribution.

5.3 Type 2 Diabetes and Metabolic Effects

A 2024 review of 20 studies involving 953 adults with type 2 diabetes found that taking astragalus in addition to the medicine metformin reduced fasting blood glucose and hemoglobin A1C more than metformin alone.

A systematic review and meta-analysis of 20 clinical studies including 953 patients with type 2 diabetes found that the use of astragalus as an adjunct treatment was associated with lower fasting plasma glucose levels (WMD: −0.67, 95% CI −1.13 to −0.20) and glycated hemoglobin A1C (HbA1c).

Astragalus polysaccharide (APS) is a key active ingredient isolated from Astragalus membranaceus that has been reported to be a potential treatment for obesity and diabetes by regulating lipid metabolism and adipogenesis, alleviating inflammation, and improving insulin resistance.

Evidence strength: Moderately encouraging at the meta-analytic level, but the evidence base consists largely of small trials from China with adjunctive (not solo) astragalus use, high heterogeneity, and variable methodological quality.

5.4 Cardiovascular Disease and Heart Failure

One research synthesis found that participants receiving astragalus were more likely to show improvement on electrocardiogram (ECG) measures, and blood biomarkers related to heart function, including creatine kinase, creatine kinase isoenzyme (CK-MB), lactate dehydrogenase, cardiac troponin I, and aspartate aminotransferase. However, the results may not be generalizable, since all the studies were conducted in China, the study sizes were small, and many were of low quality.

In clinical studies, a positive symptomatic effect of astragalus on dyspnea, chest distress, and angina, coupled with an improvement in electrocardiographic parameters and cardiac output has been described in small observational studies including patients with congestive heart failure and ischemic heart disease. However, these studies are not available in the English language. To date, data from high-quality clinical trials investigating the efficacy and safety of astragalus for the treatment of cardiovascular diseases are lacking.

One trial explored the effects of Astragalus on cardiac function and serum TNF-alpha level in patients with chronic heart failure (CHF). Forty-five patients were randomized to a Chinese medicine group and a Western medicine group; standard treatment including digoxin and diuretics was administered to both groups, but the CM group received oral Astragalus granule additionally at the dosage of 2.25 g twice a day, with treatment continued for two weeks. NYHA cardiac functional grading, serum TNF-alpha level, left ventricular ejection fraction (LVEF), and six-minute walk distance were measured before and after treatment. The study concluded that Astragalus can alleviate calcium overload-induced myocardial damage and improve both systolic and diastolic functions of the heart in patients with CHF.

Evidence strength: Preclinical and early clinical evidence is suggestive; however, adequately powered, high-quality randomized controlled trials in cardiovascular disease are absent. Much of the evidence is from small Chinese trials not available in English-language literature.

5.5 Oncology — Adjunctive Use

Current evidence indicates that Astragalus and its active metabolites exert notable cytotoxic and pro-apoptotic effects, primarily demonstrated through in vitro experiments and supported by some animal studies. Recent randomized controlled trials and meta-analyses further suggest that Astragalus may provide adjunctive benefits by alleviating chemotherapy-related adverse effects and improving quality of life in cancer patients.

Meta-analyses have shown associations between astragalus and reductions in chemo-induced nausea and vomiting, chemo-induced gastrointestinal toxicity, radiation-induced lung injury, and improvements in quality of life in patients with hepatocellular cancers.

Numerous in vitro and in vivo experimental data indicate that A. membranaceus saponins exhibit significant anti-cancer effects through multiple mechanisms, especially in inhibiting tumor cell proliferation, migration, invasion, and induction of apoptosis. However, significant strides are yet to be made before A. membranaceus saponin can be developed into a marketed drug, and studies targeting A. membranaceus saponin are still limited.

Research has systematically reviewed a wide range of clinical trials and laboratory studies of astragalus polysaccharide (APS) and elucidated the potential feasibility of using APS in activating adoptive immunotherapy. In view of the multiple functions of APS in immunotherapy and tumor microenvironment, a combination of APS and immunotherapy in cancer treatment has a promising prospect.

Evidence strength: The direct anticancer evidence at the clinical level is preliminary and largely indirect (quality of life outcomes; adjunctive use). Most mechanistic data are preclinical (in vitro and animal models). Clinical trials examining direct tumor responses are lacking.

5.6 Telomere Biology and Anti-Aging

TA-65, a single chemical entity purified from the Astragalus membranaceus species, has been demonstrated to increase telomerase activity and lengthen telomeres in mice and humans. Cycloastragenol is a triterpenoid isolated from various legume species in the genus Astragalus that is purported to have telomerase activation activity. A preliminary in vitro study on human CD4 and CD8 T cells found that cycloastragenol may moderately increase telomerase activity and inhibit the onset of cellular senescence.

TA-65 was tested in a randomized, double-blind, and placebo-controlled trial in 117 healthy adults seropositive for cytomegalovirus (CMV) between the ages of 53 and 87 years. Participants were treated with placebo or TA-65 at doses of 250 units (250U) or 1000U for one year. Treatments were dosed in 104-day cycles, involving 90 days of active treatment followed by 14 days of no treatment.

The study demonstrated that one year of treatment with TA-65 significantly enhanced telomerase activity in immune cells, resulting in a marked reduction in systemic inflammatory markers such as IL-6 and TNF-α, and improved lymphocyte proliferation and decreased signs of immune senescence.

A PRISMA-guided meta-analysis evaluated 8 randomized controlled trials (RCTs, n=750 participants; mean age 63.3 years) assessing TA-65's effects on telomere dynamics, functional aging indices, and safety outcomes. However, while telomerase activation offers a promising strategy to counteract aging, its paradoxical role in carcinogenesis poses critical safety concerns: constitutive telomerase upregulation may fuel malignant transformation, as evidenced by TERT promoter mutations in diverse cancers. This delicate balance between anti-aging efficacy and oncogenic risk underscores the urgent need for toxicologically informed evaluations of telomerase-targeting compounds.

Evidence strength: Small RCT evidence exists for the isolated compound TA-65/cycloastragenol, showing changes in telomere-related biomarkers. Clinical significance for long-term aging or disease outcomes remains unproven. Oncogenic theoretical risk from constitutive telomerase activation requires continued evaluation.

5.7 Upper Respiratory Infections and Allergic Rhinitis

Among 48 adults with allergic rhinitis treated with an herbal, vitamin, and mineral combination product containing astragalus versus placebo for 6 weeks, allergic symptoms improved more with the herbal supplement and "adverse events were not connected with the study drug."

Clinical research indicates that astragalus, alone or in combination formulas, may be beneficial for herpes keratitis, recurrent tonsillitis, seasonal allergic rhinitis, myocarditis, reperfusion injury, congestive heart failure, hepatic fibrosis, viral hepatitis, diabetic nephropathy, lupus nephritis, membranous nephropathy, recovery from stroke, burns, leukopenia, tuberculosis, nonsquamous cell lung cancer, and cancer survival.

Evidence strength: Evidence for upper respiratory indications is limited to small trials, often using combination products containing astragalus alongside other ingredients, making it impossible to attribute effects to astragalus alone. NCCIH concludes there is insufficient reliable evidence to support any single health claim.

5.8 Neuroprotection and Cognition

Astragalus membranaceus has gained increasing recognition for its potential in treating central nervous system (CNS) disorders. Reviews have aimed to systematically integrate the mechanisms of action of A. membranaceus and its bioactive compounds on CNS diseases, with a focus on exploring therapeutic potential.

Analysis reveals that A. membranaceus and its bioactive compounds, particularly Astragaloside IV (AS-IV) and Astragalus polysaccharides (APS), exert multifaceted neuroprotective effects.

Astragalus has been long used for fatigue and immune stimulation as part of traditional medicine, but clinical relevance is unclear due to the prevalence of low-quality studies conducted to date. Astragalus may exert antioxidant, anti-inflammatory, and anti-apoptotic effects, but benefits may be below the level of clinical meaningfulness.

Evidence strength: Predominantly preclinical. Human clinical trials evaluating astragalus for cognitive or neurological outcomes are sparse and of limited quality. No clinical conclusions can be drawn at this stage.

6. Body Systems and Health Areas Associated with Astragalus

• Immune system: Immunomodulation (both stimulation and modulation of inflammatory cytokines); used historically and studied clinically in contexts ranging from cancer adjunct therapy to autoimmune-related nephritis.
• Renal system: Chronic kidney disease, membranous nephropathy, lupus nephritis, diabetic nephropathy; studied in multiple meta-analyses.
• Cardiovascular system: Heart failure, ischemic heart disease, atherosclerosis, arrhythmia; evidence primarily preclinical and from small Chinese trials.
• Metabolic/endocrine system: Type 2 diabetes mellitus, obesity, insulin resistance, dyslipidemia; studied as adjunct to metformin.
• Respiratory system: Upper respiratory infections, allergic rhinitis, asthma; limited small-trial evidence.
• Central nervous system: Neuroinflammation, neuroprotection, cognitive function; predominantly preclinical evidence.
• Cellular aging/telomere biology: Telomere length maintenance via cycloastragenol/TA-65; small RCT evidence.
• Oncology (adjunctive): Mitigation of chemotherapy adverse effects, quality of life; meta-analytic level evidence, direct antitumor evidence preclinical only.
• Liver: Hepatoprotection, hepatitis, liver fibrosis; preclinical data, limited clinical evidence.
• Integumentary system: Wound healing, promoted topically; insufficient clinical evidence per NCCIH.

7. Dosage Forms and Reported Dosages

Dosages reported in scientific literature vary substantially by indication, preparation type, and whether astragalus is used alone or in combination formulas.

• General oral use: Astragalus may be safe when used orally; taking up to 60 grams per day for as long as 4 months does not seem to cause adverse effects.
• Heart failure trial: Astragalus granule was given at the dosage of 2.25 g twice a day for two weeks.
• TA-65 (cycloastragenol) trials: TA-65 was tested in a randomized, double-blind, placebo-controlled trial in 117 healthy adults; participants were treated with placebo or TA-65 at doses of 250 units (250U) or 1000U for one year.
• Allergic rhinitis trial: 48 adults with allergic rhinitis were treated with an herbal, vitamin, and mineral combination product containing astragalus versus placebo for 6 weeks.
• Diabetes adjunct: A 2024 review of 20 studies involving 953 adults with type 2 diabetes examined taking astragalus in addition to the medicine metformin. Specific dosages varied across the included studies.

A thorough safety evaluation across dose ranges has not been done. Clinical trials research has used doses up to 60 grams daily of raw root material for periods of up to four months, though preparations differ (raw root vs. extract vs. injection vs. granule).

8. Safety Considerations and Drug Interactions

General Safety Profile

Astragalus has not been reported to cause clinically apparent liver injury. In small clinical studies, the astragalus-based supplement ASTCOQ02 was not associated with changes in weight, blood pressure, heart rate, immune parameters, ECG measures, or biochemical markers of liver, kidney, and metabolic function over the course of six months. Astragalus is rated as unlikely to cause liver toxicity by NIH LiverTox.

In patients with heart failure, common adverse events in trials were hypotension, sinus bradycardia, nausea, dizziness, cough, headache, palpitations, and elevated transaminases, but the addition of astragalus did not increase the incidence of these events. Overall, the addition of astragalus has not exacerbated symptoms in clinical populations, and in some cases, may mitigate side effects associated with conventional medicines.

Fatigue, malaise, headache, and lowering of blood pressure have been reported.

Autoimmune Conditions

Because astragalus might worsen symptoms of autoimmune diseases, people with autoimmune diseases should avoid using astragalus.

Pregnancy and Reproductive Toxicity

Astragaloside IV has been shown to have maternal and fetal toxicity at doses ≥ 1 mg/kg in pregnant rats. Safety in human pregnancy has not been established.

Drug Interactions

Because of its possible effects on CYP enzyme activity, the potential for herb-drug interactions with astragalus should be considered before it is used. However, clinically apparent astragalus-drug interactions have not been reported.

• Immunosuppressants: Astragalus may interact with medications that suppress the immune system. Astragalus can antagonize the effects of immunosuppressants. In a patient with refractory nephrotic syndrome, concomitant use of herbal medicine granules containing astragalus was associated with nearly a 50% reduction in tacrolimus concentration.
• Anticoagulants: Astragalus and its constituents showed anticoagulant properties in vitro and may increase the risk of bleeding when used with these drugs.
• Hormonal therapies: Astragalus and its constituents have estrogenic properties and may interfere with their actions. Clinical relevance is not known.
• P-glycoprotein substrates: Astragalus polysaccharides may inhibit the P-glycoprotein efflux pump function.
• Antihypertensives: Astragalus by itself can lower blood pressure, which should be considered when taken with medications to lower blood pressure.

Astragalus is a popular immunostimulant sought by many patients with cancer. Physicians should be aware of the lack of robust data and its potential for interactions with some prescription medications including immunosuppressants.

Telomerase Activation and Theoretical Oncogenic Risk

While telomerase activation offers a promising strategy to counteract cellular aging, its paradoxical role in carcinogenesis poses critical safety concerns: constitutive telomerase upregulation may fuel malignant transformation. This delicate balance between anti-aging efficacy and oncogenic risk underscores the urgent need for toxicologically informed evaluations of telomerase-targeting compounds.

Overall Evidence Caveat

There is not sufficient reliable scientific evidence to know whether astragalus is useful for any health condition. This reflects the consistently preliminary or low-quality nature of available clinical trials, and the NCCIH's assessment based on reviews through 2024. Nearly all systematic reviews in this area note small sample sizes, high heterogeneity, geographic concentration in China, and methodological limitations as recurring constraints.

References

• National Center for Complementary and Integrative Health (NCCIH) — Astragalus: Usefulness and Safety
• NIH LiverTox — Astragalus (National Institute of Diabetes and Digestive and Kidney Diseases)
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• Astragalus Membranaceus—Can It Delay Cellular Aging? PMC, 2025
• Research Progress on Chemical Components of Astragalus membranaceus and Treatment of Metabolic Syndrome. PMC, 2025
• Biosynthesis and Pharmacological Activities of Flavonoids, Triterpene Saponins and Polysaccharides Derived from Astragalus membranaceus. PMC, 2023
• Research Progress on the Anti-Cancer Effects of Astragalus membranaceus Saponins and Their Mechanisms of Action. PMC, 2024
• Recent Advances in the Mechanisms and Applications of Astragalus Polysaccharides in Liver Cancer Treatment. PMC, 2025
• Exploring the Neuroprotective Potential of Astragalus membranaceus in Central Nervous System Diseases. PMC, 2025
• Cycloastragenol and Astragaloside IV activate telomerase and protect nucleus pulposus cells against high glucose-induced senescence and apoptosis. PMC, 2021
• Astragalus (a traditional Chinese medicine) for treating chronic kidney disease — Cochrane-related review. PMC, 2023
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• The Current Application and Future Prospects of Astragalus Polysaccharide Combined With Cancer Immunotherapy. PMC, 2021
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• Targeting Telomere Shortening in Vascular Aging and Atherosclerosis: Therapeutic Promise of Astragalus membranaceus. PMC, 2025
• Double-Blind, Placebo-Controlled, Randomized Clinical Trial Demonstrates Telomerase Activator TA-65 Decreases Immunosenescent CD8+CD28- T Cells in Humans. OBM Geriatrics, 2021
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• The potential of astragalus polysaccharide for treating diabetes and its action mechanism. PMC, 2024
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