This is my first time looking at letrone, but I'm a little shocked no one has pointed this out yet...
"The results indicated that atractylenolide I (1),
atractylenolide II (2) and atractylenolide III (3) had inhibition ratios of 94.56 ± 0.70%,
90.93 ± 1.41% and 86.31 ± 8.46%, respectively, at a concentration of 10 μM. "
So you need a concentration of
10 uM to get this strong AI effect. The writeup lists isolated absorption data, but does not speak to subsequent metabolism. Thankfully, there is a paper showing what happens to the compound after it is administered:
Pharmacokinetic profile of phytoconstituent(s) isolated from medicinal plants?A comprehensive review
Cmax is the MAXIMUM concentration achieved after dosing. The dose was 20g/kg in rats, equivalent to 260 grams in a 180 lb person.
The Cmax at this dose was 7.99 ug/L, which means the molar concentration was
0.035 uM. This concentration is 300 times less than the concentration shown to have AI effects (and keep in mind, 0.035 uM is the MAXIMUM concentration). Assuming linear pharmacokinetics, you would need:
300 (the factor by which the concentration is too low) x 260g (the dose administered to get this concentration).
This would mean that to get the results advertised in this thread/the product writeup, you would need to take 78,000 grams of pure atractylenolide. For most people, that would mean eating your entire body weight in pure compound. Take into account that letrone is an extract and not the pure compound, and you're probably looking at 100kg+ of this compound in one sitting.
The study also showed a halflife of 2 hours. This cannot even be remotely compared to aromasin (bioactive life 72 hours), arimidex (48-72 hours), etc...
1 MILLIGRAM of arimidex every 3 days would have a similar effect to eating
100,000 grams of letrone's active compound every 2 hours.
To even say that letrone can help control estrogen in people taking aromatizing compounds is frankly very irresponsible. We're talking about people here, not just numbers on a sales sheet.