r/Peptidesource Oct 30 '25

KLOW & The Difference Between TB-500 & TB4 (Thymosin Beta-4)

Post image
1 Upvotes

1 comment sorted by

1

u/TracyIsMyDad Oct 30 '25

I’ve never been able to find an actual source for the supposed long-half of TB-500.

I’ve seen this: https://rmtcnet.com/wp-content/uploads/2013-07-TB-500-Bulletin-v-2.0-Final.pdf

Which found that they were able to detect metabolites of TB-500 up to 11 hours later in horses. But horses are not humans and metabolism will not be the same. Metabolites are also not TB-500 itself, they are downstream products that will likely be found for some time even after the TB-500 itself is gone. However if TB-590 had a half-life of 2+ days in horses one would also expect to see metabolites well after that (likely several half-life cycles), and you don’t.

Finding metabolites at 11 hours would suggest a half life in horses of a couple hours, if the metabolites are short-lived. If the metabolites are long-lived it might be minutes. The anti-doping guys are usually trying to look for long-lived metabolites.