I appreciate all the info! I can’t wait to see the full write up. I actually hadn’t ever heard this about forskolin, I’ll have to read up on that some more.
We were very surprised when we started looking into forskolin. It's very popular as a pharmaceutical probe compound for cell-line experiments, but it turns out that the data on its use in humans or animals is very poor.
There's
a Chinese paper -- as far as I can tell, available only in Chinese -- which states that the oral bioavailability of Forskolin in rats is 0.52%. (Table 2, F(%). I can't read Chinese, either, but that part's fortunately clear!)
The fulltext of the paper I linked to previously is
here, and its reference #4 is that Chinese paper. This newer paper indicates that solubility, not permeability, is what limits forskolin's oral bioavailability. That, in other words, it's a classic
BCS Class II substance -- and a very extreme example of that type, as its solubility in water seems to be somewhere under 0.01mg per ml.
Forskolin also happens to be a P-gp substrate, which means that there's a protein that tries to block its absorption -- and, if absorbed, tries to kick it out of circulation. This, in itself, typically reduces bioavailability quite markedly.
And then there's the twist. The paper closes with: "
Unfortunately, no studies describing the metabolism of forskolin in vivo have been reported so far." As far as I can tell, this was true at the time the paper was written, and it remains true now. Even if forskolin is absorbed, what happens to it from that point on is anybody's guess.
So forskolin is a compound with near-zero solubility, which also happens to be a P-gp substrate, and nobody knows how it's metabolized. Seems to me that 0.52% bioavailability is pretty good, under the circumstances! But it still means that of a 50mg dose of forskolin, only ~250mcg can be utilized.
Back on topic: I don't think that people who buy Ultratest are "N=1 labrats." Tongkat Ali is already
very highly regarded and well-studied as a testosterone booster, and here it's combined with liquid VD3 and K2 -- the latter at a real solid dose.
In addition to that already solid base, the product contains a couple of innovative ingredients, which we're very proud of, and which should impart many additional benefits.