--- topic: "Astragalus" title: "Immune Support, Telomeres, and Longevity Herb" order: 1 description: "What the research shows about astragalus (Huang Qi): immune modulation, telomere length, heart protection, and chemotherapy support. Most of the evidence is laboratory work and small trials." question: "Does astragalus really strengthen the immune system and support longevity?" answer: "Astragalus may rebalance immune markers and lengthen telomeres, based on small trials, but benefits for infections or lifespan have not been shown." actions: - "Use it as a consistent tonic over weeks to months rather than for acute illness; it is not fast-acting." - "Traditional use is 9–30 g of dried root a day as a decoction, or 500–1,500 mg of standardized extract." - "For immune goals, choose polysaccharide-standardized products (40–70%); the telomere trial used a specific astragalus-based supplement [3]." cautions: - "People on immunosuppressant medications sometimes avoid it because it activates immunity; check with your doctor first." - "Use caution in pregnancy: high-dose use has not been studied." - "Chemotherapy-support data come mostly from one geographic context; discuss any use during cancer treatment with your oncologist [5]." confidence: 2 confidenceNote: "One 40-person RCT on telomere length, one 106-person controlled trial on immune markers, plus reviews of mostly combination-formula studies." evidenceSummary: rctCount: 1 observationalCount: 0 metaAnalysisCount: 1 totalParticipants: "~150" replicated: false newestStudyYear: 2024 references: - id: "1" pmid: "26916911" title: "Astragalus membranaceus: A Review of its Protection Against Inflammation and Gastrointestinal Cancers" authors: "Auyeung KK, Han QB, Ko JK" year: 2016 journal: "American Journal of Chinese Medicine" - id: "2" pmid: "15015443" title: "Modulatory effect of Astragalus membranaceus on Th1/Th2 cytokine in patients with herpes simplex keratitis" authors: "Mao SP, Cheng KL, Zhou YF" year: 2004 journal: "Zhongguo Zhong Xi Yi Jie He Za Zhi" - id: "3" pmid: "39275278" title: "A Natural Astragalus-Based Nutritional Supplement Lengthens Telomeres in a Middle-Aged Population: A Randomized, Double-Blind, Placebo-Controlled Study" authors: "de Jaeger C, Kruiskamp S, Voronska E, Lamberti C, Baramki H, Beaudeux JL, Cherin P" year: 2024 journal: "Nutrients" - id: "4" pmid: "37251311" title: "Review on the protective mechanism of astragaloside IV against cardiovascular diseases" authors: "Yang C, Pan Q, Ji K, Tian Z, Zhou H, Li S, Luo C, Li J" year: 2023 journal: "Frontiers in Pharmacology" - id: "5" pmid: "32243990" title: "Anti-tumor effects and mechanisms of Astragalus membranaceus (AM) and its specific immunopotentiation: Status and prospect" authors: "Li S, Sun Y, Huang J, Wang B, Gong Y, Fang Y, Liu Y, Wang S, Guo Y, Wang H, Xu Z, Guo Y" year: 2020 journal: "Journal of Ethnopharmacology" - id: "6" pmid: "32265719" title: "A Review of the Pharmacological Action of Astragalus Polysaccharide" authors: "Zheng Y, Ren W, Zhang L, Zhang Y, Liu D, Liu Y" year: 2020 journal: "Frontiers in Pharmacology" - id: "7" pmid: "26950204" title: "A Natural Product Telomerase Activator Lengthens Telomeres in Humans: A Randomized, Double Blind, and Placebo Controlled Study" authors: "Salvador L, Singaravelu G, Harley CB, Flom P, Suram A, Raffaele JM" year: 2016 journal: "Rejuvenation Research" - id: "8" pmid: "21426483" title: "The telomerase activator TA-65 elongates short telomeres and increases health span of adult/old mice without increasing cancer incidence" authors: "Bernardes de Jesus B, Schneeberger K, Vera E, Tejera A, Harley CB, Blasco MA" year: 2011 journal: "Aging Cell" - id: "9" pmid: "29344421" title: "Anti-Aging Implications of Astragalus Membranaceus (Huangqi): A Well-Known Chinese Tonic" authors: "Liu P, Zhao H, Luo Y" year: 2017 journal: "Aging and Disease" --- Astragalus (*Astragalus membranaceus*, also called Huang Qi in traditional Chinese medicine) is a root used for about 2,000 years as an immune tonic, and it is one of the most studied herbs in Chinese medicine. Laboratory research suggests that it modulates immune responses and contains compounds that activate telomerase — the enzyme that maintains the protective caps on your chromosomes. [1][9] In a randomized, double-blind, placebo-controlled trial published in 2024, 40 middle-aged volunteers taking an astragalus-based supplement had significantly longer telomeres after six months, while the placebo group showed no change. [3] A small trial in patients with herpes simplex keratitis found that astragalus moved an imbalanced cytokine profile back toward that of healthy people. [2] Whether any of this translates into fewer infections or better health has not been shown in large human trials. ## How Astragalus Works Astragalus root contains many bioactive compounds. The most studied fall into three main families: **astragalus polysaccharides (APS)**, **saponins** (particularly astragaloside IV), and **flavonoids** (notably calycosin and formononetin). [1][6] Each class has distinct but overlapping biological actions. ### Immune Modulation: Restoring Balance, Not Just Boosting The immune action most often described for astragalus polysaccharides is **immunomodulation** — a more nuanced effect than simple immune stimulation. Reviews of the laboratory and animal literature report that APS promotes the proliferation of immune cells, stimulates the release of cytokines, and affects antibody secretion and immune signaling. [6] Described effects include: - Greater immune cell proliferation and cytokine release, with effects on immunoglobulin secretion and immune signaling [6] - Activation of M1 macrophages and of T cells' tumor-killing function in tumor models, with improved systemic immunity [5] Most of this work was done in cells and animals, so it shows what astragalus can do rather than what a daily supplement reliably does in people. A randomized clinical trial in 106 patients with herpes simplex keratitis — an infection of the cornea — compared astragalus with the antiviral ribavirin. Patients had higher IL-4 and IL-10 and lower IL-2 and gamma-interferon than healthy people; these levels improved in the astragalus group, and did not change in the ribavirin group. The authors read this as modulation of a Th1/Th2 imbalance. [2] ### Telomerase Activation: Cellular Longevity Telomeres are the protective caps on the ends of chromosomes. They shorten with each cell division, and when they become critically short, cells enter a senescent state — no longer able to divide, contributing to aging and age-related disease. Telomerase counteracts this by rebuilding telomere length, and it is normally only active in stem cells and certain immune cells. Extracts of astragalus root have been reported to increase telomerase activity. [9] The best-known one is TA-65, a small-molecule telomerase activator purified from the root of *Astragalus membranaceus*. In mouse cells, TA-65 increased average telomere length and reduced the percentage of critically short telomeres through the telomerase pathway. In female mice it improved some healthspan indicators — glucose tolerance, osteoporosis, and skin fitness — without significantly increasing cancer incidence. [8] Two randomized, placebo-controlled trials in people have measured telomere length: - **2024 astragalus-based supplement trial:** 40 healthy volunteers (mean age 56) took the supplement or placebo for six months. The supplement group had significantly longer median telomeres (p = 0.01) and short telomeres (p = 0.004) and a lower percentage of short telomeres; the placebo group showed no change. [3] - **2016 TA-65 trial:** 117 relatively healthy adults aged 53–87 who were positive for cytomegalovirus took TA-65 or placebo for one year. With the low dose (250 U), telomere length rose by 530 ± 180 bp (p = 0.005), while the placebo group lost 290 ± 100 bp (p = 0.01). The high dose (1,000 U) showed a trend that did not reach statistical significance. [7] Each trial tested a specific commercial formulation, so the results cannot be assumed to apply to ordinary astragalus root. Both trials measured telomere length in blood cells; neither measured whether longer telomeres improved health. ### Cardiovascular Protection Astragaloside IV has a second major area of laboratory research: the heart and vascular system. A 2023 review describes protective effects on heart muscle through several pathways: - **Antioxidant defense**: reduces oxidative stress in cardiac tissue - **Anti-inflammatory action**: dampens inflammatory signaling in the myocardium - **Anti-fibrotic effects**: reduces the scarring that stiffens heart tissue after injury - **Calcium homeostasis**: helps regulate intracellular calcium - **Autophagy regulation**: affects the cellular cleanup processes in heart muscle cells It also describes effects on blood vessels, including relaxing them, protecting the cells that line them, and stabilizing atherosclerotic plaques in experimental models. [4] These findings come mainly from cell and animal experiments, and the review notes that the bioavailability of astragaloside IV is low. [4] ## Dosage and Forms Traditional use and modern research have used widely varying preparations. For general guidance: - **Dried root / decoctions**: 9–30 g of dried root per day in traditional TCM formulas — this is the historical standard - **Standardized extracts**: 500–1,500 mg/day of dried root equivalent, often standardized to astragaloside IV content - **Polysaccharide-standardized supplements**: most immune-focused formulas are standardized to 40–70% polysaccharide content - **Telomere products**: the two telomere trials used branded formulations (a specific astragalus-based supplement [3] and TA-65 at 250 or 1,000 units a day [7]) rather than plain root powder The 2024 trial reported no adverse side effects over six months [3], and a 2023 review concluded that astragaloside IV is safe but should be used cautiously in pregnant women [4]. Because astragalus is considered immune-activating, people with autoimmune conditions or who take immunosuppressant medications are often advised to check with their clinician first; the concern is theoretical rather than a documented harm. ## When to Use It Astragalus is traditionally used for: - **Frequent colds or respiratory infections** — an immune tonic used seasonally or long-term (this is traditional use; the human trials above did not test it) - **Recovery from illness or medical treatment** — reviews of clinical reports describe astragalus-based treatments reducing the toxicity of chemotherapy and other drugs and supporting immune function during cancer treatment [1][5] - **Cardiovascular support** — an area of laboratory interest, not yet of proven clinical benefit [4] - **Longevity and anti-aging strategies** — primarily for its telomere-related properties, with the caveats above It is not a fast-acting herb. Unlike echinacea (best taken acutely for a few days at illness onset), astragalus is traditionally used consistently over weeks to months as a tonic — building resilience over time rather than providing immediate acute relief. See our [Echinacea page](/echinacea/immune-support-and-cold-prevention) for a complementary short-term immune herb, our [Jiaogulan page](/jiaogulan/immortality-herb) for another TCM longevity adaptogen, and our [Telomeres page](/telomeres/cellular-aging-and-longevity) for broader context on cellular aging. ## Evidence Review ### Auyeung, Han & Ko 2016 — Comprehensive Review The Auyeung et al. review [1] in the *American Journal of Chinese Medicine* summarizes the properties of *Astragalus membranaceus* and its major constituents (polysaccharides, flavonoids, and saponins) from experimental and clinical studies, with a focus on anti-inflammatory and cancer-protective effects. Its main points: - Contemporary use centers on immunomodulating, antioxidant, anti-inflammatory, and anticancer effects - Astragalus-based treatments have been reported to ameliorate the toxicity of other drugs given at the same time, including immunosuppressants and cancer chemotherapeutics - A novel astragalus saponin extract called AST has antitumor effects in gastrointestinal cancer models, and the review discusses how the herb and AST influence the immune system, modulate cancer-related signaling pathways, and interact with transcription molecules Most human studies of astragalus use it inside multi-herb formulas, which makes the effect of astragalus alone hard to isolate. ### Mao, Cheng & Zhou 2004 — Clinical Immunomodulation This randomized clinical trial [2] enrolled 106 patients with herpes simplex keratitis (HSK), compared astragalus treatment with ribavirin (an antiviral drug), and measured serum cytokines by ELISA against 62 healthy controls. - Before treatment, HSK patients had significantly higher IL-4 and IL-10 (Th2-type cytokines) and significantly lower IL-2 and gamma-interferon (Th1-type cytokines) than the healthy controls (all P < 0.01) - After treatment, these parameters were significantly improved in the astragalus group - No change occurred in the ribavirin group The clinical importance is not that astragalus stimulated immunity in a healthy person, but that it rebalanced a disturbed cytokine profile in patients with an eye infection. It was a single trial in one condition and reported cytokine levels, not clinical outcomes in the abstract. ### de Jaeger et al. 2024 — Randomized Controlled Trial on Telomere Length Published in *Nutrients*, this double-blind, placebo-controlled RCT [3] tested an astragalus-based supplement in 40 healthy volunteers (mean age 56.1 ± 6.0 years; 20 per arm) over six months. All participants completed the study, and no adverse side effects were reported. The supplement group had significantly longer median telomere length (p = 0.01) and short telomere length (p = 0.004) and a lower percentage of short telomeres (< 3 kbp); the placebo group showed no change. The authors attribute this to increased telomerase activity, and they note that the result follows an earlier open prospective trial of the same supplement. The trial is small and short, it tested one specific formulation, and it measured telomere length rather than disease. Independent replication and longer follow-up would be needed to know whether the change matters for health. ### Salvador et al. 2016 — TA-65 Randomized Trial This trial [7] randomized 117 relatively healthy, cytomegalovirus-positive adults aged 53–87 to a low dose (250 U) or high dose (1,000 U) of TA-65 or placebo for 12 months. The low dose significantly increased telomere length (530 ± 180 bp; p = 0.005) while the placebo group significantly lost telomere length (290 ± 100 bp; p = 0.01). The high dose showed a trend toward improvement that did not reach significance, and changes in the low-dose group were similar for median and 20th-percentile telomere length. The participants were all cytomegalovirus-positive, so the results may not generalize to everyone. ### Mouse Healthspan Study Bernardes de Jesus et al. 2011 [8] showed that TA-65, purified from the root of *Astragalus membranaceus*, increased average telomere length and decreased the percentage of critically short telomeres and of DNA damage in mouse cells with a single copy of the telomerase RNA gene, but not in cells lacking telomerase, indicating that it acts through the telomerase pathway. As part of the diet, it elongated critically short telomeres in mice and, in female mice, improved glucose tolerance, osteoporosis, and skin fitness without significantly increasing global cancer incidence. The absence of an increase in cancer is an important safety signal, because telomerase activation has a theoretical cancer risk, but it is mouse data. ### Reviews of Astragalus Compounds Zheng et al. 2020 [6] reviewed the pharmacology of astragalus polysaccharide, summarizing effects on immune regulation (immune organ index, immune cell proliferation, cytokine release, immunoglobulin secretion, and immune signaling), anti-aging, tumor immunity, antiviral activity, blood glucose and lipid regulation, anti-fibrosis, and antimicrobial and anti-radiation effects. It is a review of mostly preclinical work. Liu et al. 2017 [9] reviewed the anti-aging implications of astragalus, noting that its extracts can increase telomerase activity, have antioxidant, anti-inflammatory, immunoregulatory, anticancer, hypolipidemic, antihyperglycemic, and hepatoprotective effects, and that a proprietary extract (TA-65) was associated with a significant age-reversal effect in the immune system. The authors' focus is lifespan extension, vascular aging, brain aging, and anticancer effects, based on experimental and clinical studies. ### Yang et al. 2023 — Astragaloside IV and Cardiovascular Disease This review in *Frontiers in Pharmacology* [4] describes the mechanisms by which astragaloside IV protects the myocardium: antioxidative stress, anti-inflammatory effects, regulation of calcium homeostasis, improvement of myocardial energy metabolism, anti-apoptosis, anti-cardiomyocyte hypertrophy, anti-myocardial fibrosis, regulation of myocardial autophagy, and improvement of myocardial microcirculation. In blood vessels, it describes protection of endothelial cells through antioxidative and anti-inflammatory pathways, relaxation of vessels, stabilization of atherosclerotic plaques, and inhibition of the proliferation and migration of vascular smooth muscle cells. The review states that the bioavailability of astragaloside IV is low and that toxicology studies indicate it is safe but should be used cautiously in pregnant women. It is a mechanistic review; it does not establish clinical benefit. ### Li et al. 2020 — Immunopotentiation and Cancer Support The Li et al. review [5] in the *Journal of Ethnopharmacology* synthesized evidence for astragalus as a direct antitumor agent and an adjunct to cancer therapy. Surgery and chemoradiotherapy are often accompanied by suppression of host immunity, which raises the risk of metastasis. The review reports that the active ingredients of astragalus and astragalus-based TCMs, combined with chemotherapy, can enhance antitumor efficacy in cancer patients as well as reduce complications and side effects of chemotherapy. In cancer models and cell lines, astragalus shrank or stabilized tumors through direct antiproliferative or pro-apoptotic effects, and it ameliorated immunosuppression by activating M1 macrophages and T-cell tumor-killing function; it is also reported to improve systemic immunity. The authors say the combination of astragalus with immune checkpoint therapies looks promising but that direct efficacy and mechanisms alongside chemotherapy or other therapies need more in vivo validation and further clinical investigation. ### Evidence Strength Summary **Immune function**: Moderate in the laboratory, low-to-moderate in humans — consistent cell and animal data and one small randomized trial (106 patients with herpes simplex keratitis) showing cytokine rebalancing. Confidence: **moderate-to-low**. **Telomere lengthening**: Preliminary — two placebo-controlled trials of branded formulations (40 and 117 adults) found longer telomeres in blood cells, with no measure of health outcomes and no independent replication yet. Confidence: **low-to-moderate**. **Cardiovascular protection**: Preliminary — strong mechanistic and animal data, but no human trial of astragalus for heart outcomes is cited here. Confidence: **low**. **Cancer adjunct / chemotherapy support**: Preliminary-to-moderate — reviews of clinical reports describe fewer chemotherapy complications and better immune function, but the authors call for further clinical investigation. Confidence: **low-to-moderate**. Overall, astragalus is a well-characterized traditional herb with plausible mechanisms and encouraging early human data on immune balance and telomere length, but it has not been shown in large trials to prevent infections, slow aging, or protect the heart.