Astragalus & Cycloastragenol (TA-65)

What it is

What is meant is the dried root of Astragalus membranaceus, a legume that is today also listed botanically as Astragalus mongholicus. According to Cochrane, it is one of the most widely used herbs in traditional Chinese medicine. In its 1999 monograph, the World Health Organization names triterpene saponins, the astragalosides, and polysaccharides as the main constituents. Traditionally, the root is used to strengthen the immune system and endurance; the US health institute NCCIH counts it among the adaptogens.

Cycloastragenol is a triterpene aglycone from the root, that is, the sugar-free core of its saponins; the astragalosides are apparently partly metabolized to cycloastragenol in the body. According to one study group, TA-65 is an encapsulated form of cycloastragenol purified from the root, with better bioavailability, distributed by the company T.A. Sciences of New York. There is thus a world of difference between a root powder and a highly purified single substance, legally as well.

How it is supposed to work

Telomeres are the protective caps at the ends of chromosomes. They become somewhat shorter with every cell division, and very short telomeres send cells into the resting state of senescence. Telomerase can lengthen them again, but it is largely switched off in normal body tissue. The idea behind TA-65 is simple: gently switch on the enzyme and thereby rescue the critically short telomeres.

In the laboratory, this works. In 2008, cycloastragenol increased the proliferative capacity and antiviral strength of immune cells from HIV-infected donors, and a telomerase inhibitor abolished the effect again. In 2011, a Spanish telomere research group showed that TA-65 lengthens short telomeres in mice in a telomerase-dependent manner. Female mice afterwards had better glucose values, stronger bones and healthier skin, without more cancer. For the root itself, immunomodulating polysaccharides are also discussed.

Why the longevity scene is paying attention

TA-65 is one of the best-known products explicitly advertised with telomerase activation, and it is one of the few for which there are placebo-controlled studies in humans. In user circles, it is therefore seen as the most serious attempt to turn back the telomere clock. The root itself has the reputation of a gentle immune adaptogen with centuries of tradition.

What the studies show

TA-65 after myocardial infarction

90 heart attack patients over 65 took TA-65 or placebo for 12 months. The primary endpoint, the proportion of aged CD8 immune cells, did not change. On the other hand, the lymphocyte count rose by 285 cells per microliter, the inflammatory protein hsCRP was 62 percent lower, and there were fewer adverse events in the TA-65 group, 130 versus 185. The study was led by researchers but funded by the manufacturer.

Macular degeneration

38 people with early age-related macular degeneration received TA-65 or placebo for one year. The light sensitivity of the central retina improved by 0.97 dB compared with placebo. This is a pilot study, funded by the manufacturer.

Metabolic syndrome

40 people with metabolic syndrome took TA-65 and placebo for 12 weeks each in a crossover design. With TA-65, HDL cholesterol was higher, and waist circumference, the LDL/HDL ratio and the inflammatory messenger TNF-alpha were lower.

Root in kidney disease

A Cochrane review summarized 22 studies with 1,323 participants. Astragalus in addition to standard therapy reduced protein excretion by 0.53 g per day and raised hemoglobin and albumin. Study quality was low, and need for dialysis or mortality were not reported anywhere.

Where the data stop

Longer telomeres are a measurement, not a health gain in themselves. In the 2025 meta-analysis, neither frailty nor inflammatory markers improved, and after myocardial infarction the primary endpoint was missed. In the most important telomere study, only the low dose had a significant effect; the high dose showed merely a trend. In mice, 4 months of TA-65 did not extend lifespan, and for humans there are no data on life expectancy. Almost all TA-65 studies were paid for by the manufacturer, and the meta-analysis found larger effects in these studies. The early program data from 2011 and 2013 had no control group. An independent study with 120 older people that combined TA-65 with resveratrol had to stop this arm after 5 months because of rising LDL levels, probably due to the resveratrol, so it could not contribute anything on TA-65. The studies on the root itself are predominantly small, and in 1999 the WHO listed no clinically supported use.

Status, approval and legal

In the EU, astragalus root and its alcoholic extracts are considered not novel in dietary supplements because they were already in use before 1997. This is confirmed by the European Commission’s Novel Food Catalogue, a 2024 consultation on a 2:1 root extract and the substance list of the German federal and state governments. There are no official maximum amounts. Cycloastragenol with a purity of at least 98 percent, that is, the active ingredient of TA-65, is a different matter: following a request to the Czech authority, the European Commission classified it as a novel food that has not yet been authorized. The manufacturer had already submitted an application for authorization in 2014. Pure cycloastragenol may therefore not currently be sold as a food in the EU.

Safety

The root is considered well tolerated. According to the NCCIH, up to 60 g per day for up to 4 months does not appear to cause side effects. According to the NCCIH, people with autoimmune diseases should avoid astragalus because it could worsen their symptoms, and interactions with immunosuppressants are possible. The WHO advises against it during pregnancy and breastfeeding; animal data point to harm to the unborn child. For TA-65, the meta-analysis found no serious events over 12 months, but mild gastrointestinal complaints in 12.4 percent. In a 91-day rat study, cycloastragenol showed no harmful effects. The fundamental question remains open whether permanent telomerase activation influences cancer risk. The studies excluded people with a history of cancer, and long-term data are lacking.

Sources

• Salvador et al., Rejuvenation Res 2016 – TA-65 lengthens telomeres, RCT
• Su et al., Cell Biol Toxicol 2025 – meta-analysis on TA-65
• Bawamia et al., Geroscience 2023 – TA-65 after myocardial infarction, RCT
• Bernardes de Jesus et al., Aging Cell 2011 – TA-65 in mice
• de Jaeger et al., Nutrients 2024 – astragalus combination product and telomeres
• Zhang et al., Cochrane Database Syst Rev 2014 – astragalus in chronic kidney disease
• Zhang et al., Complement Med Res 2023 – meta-analysis on immune response
• NCCIH – Astragalus (as of May 2025)
• WHO monographs on selected medicinal plants, volume 1 (1999) – Radix Astragali
• European Commission – Novel Food Status Catalogue (Astragalus membranaceus, cycloastragenol)