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Limited evidenceLongevity & antioxidants

Cycloastragenol

The astragalus compound behind commercial telomerase activators. One small randomized trial found changes in cardiovascular markers, but no human study has convincingly shown telomere lengthening or any anti-ageing outcome.

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What the science says

  • Telomerase activation and telomere length Limited evidence

    The telomerase-activating effect is documented in cell culture; in animals, a randomized study of the branded TA-65 product in bird chicks found no increase in telomere length during development. Human telomere data come mostly from uncontrolled or industry-linked observations.

  • Cardiovascular markers Limited evidence

    A randomized controlled trial of TA-65 in patients with metabolic syndrome reported improvements in some cardiovascular markers such as HDL and glucose. It was a single small trial with surrogate endpoints and industry involvement.

  • Anti-ageing effects on skin and bone Limited evidence

    A 2026 review of Astragalus membranaceus summarizes potential anti-ageing and anticancer activity on skin and bone, based on preclinical work. No clinical trial supports these uses.

Dosage & safety

Studied doseThe metabolic syndrome trial used 16 mg/day of the branded TA-65 preparation. Generic cycloastragenol products list 5–25 mg/day, with variable and often unverified purity.
SafetyShort-term trials reported no serious adverse effects. The theoretical concern with any telomerase activator is that it could support survival of pre-malignant cells; this has not been demonstrated but has not been excluded either. Avoid with a history of cancer, in pregnancy, breastfeeding, and alongside immunosuppressants, since astragalus is immunostimulating.

How to take it

TimingMorning, once daily.
With food?With or without food.
Worth knowingGeneric cycloastragenol content is frequently unverified, so a third-party assay matters more here than the milligram number on the label.

Interactions

With medications

  • immunosuppressants (ciclosporin, tacrolimus, azathioprine, mycophenolate)

    Astragalus-derived preparations are immunostimulating and may work against the drug. do not combine without medical supervision

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Does cycloastragenol lengthen telomeres?

No human study has convincingly shown cycloastragenol lengthens telomeres; telomerase activation is documented in cell culture, and a TA-65 study in bird chicks found no increase in telomere length. The human telomere data are mostly uncontrolled or industry-linked, so the evidence is limited.

Does TA-65 have any proven benefits?

One small industry-involved randomized trial of TA-65 in metabolic syndrome reported improvements in some cardiovascular markers such as HDL and glucose. That single surrogate-marker trial is limited evidence, and no anti-ageing outcome has been shown.

How much cycloastragenol should I take?

The metabolic syndrome trial used 16 mg/day of branded TA-65, taken once daily. Generic cycloastragenol products list 5–25 mg/day, but their content is often unverified, so a third-party assay matters more than the label number.

Is cycloastragenol safe with a history of cancer?

Avoid cycloastragenol if you have a history of cancer: any telomerase activator could in theory help pre-malignant cells survive, which has not been shown but not excluded. Also avoid it in pregnancy, breastfeeding and with immunosuppressants, since astragalus is immunostimulating.

Scientific references

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