Ist tasciences.com sicher?

Highly dubious. They're piggybacking on some legitimate science in order to sell a supplement at exhorbitant prices.Shortening of telomeres is indeed associated with aging, but overexpression of telomerase (which Cycloastragenol is purported to induce) is associated with cancer. Even assuming that ingesting Cycloastragenol (or shmearing it on your skin) gets it to your cells and causes upregulation of telomerase, that could be a terrible idea.Now, the compound (probably) isn't going to lead to constitutive expression of telomerase, so any cell line that takes it up won't be fully immortalized; you can just stop treating the cells and stop upregulating telomerase. However, it could lead to the rescue of cell lines that are already reproducing too quickly, allowing other mutations to occur that DO immortalize the line.Long story short, even if the product actives telomerase, (which I highly doubt), you don't want to do that until you're sure you aren't removing the last brake on a pre-cancerous cell line.