TA-65 is a brand name of a dietary supplement. It basically stands for "Telomerase Activator for seniors 65+ looking to stop ageing". It's disclosed right on the label that the active ingredient is indeed cycloastragenol, however the manufacturer claims that it's prepared by a patented process to create a proprietary "bio-enhanced" formulation, which I presume improves bioavailability. Anecdotal postings online from people prove that via chromosomal testing, their telomeres on immune cells do indeed grow longer after taking cycloastragenol. Both astragaloside IV and cycloastragenol elongate telomeres. TA-65 comes with a hefty price tag (and obvious price-fixing as you won't find a good sale price on it anywhere) so regular astragalus supplements quickly become more attractive. One can just take a mega dosage of astragalus and reap some benefits rather than toss their wallet away at TA-65.
So to answer your question: while I don't know what exact dose will yield the same telomere elongation, you can safely take up to 3,000 mg of astragalus root each day and get satisfactory results in the long run. Take it with meals, but not with dairy.
Edited by holdout, 14 July 2014 - 08:51 PM.