Resveratrol (compound in Japanese Knotweed) has in some instances a bio-availability as low as 0%.

I found out about this today and thought I'd share.

It might explain why Buhner recommends really high doses (I've seen people take 12 grams or more per day).

Here's the study: https://docdro.id/x7qgbte

The bad news:

RES has been studied extensively as a major contributor to the health benefits associated
with the consumption of grape products. In vitro studies have clearly demonstrated the
potential of resveratrol as a “therapeutic agent”; and yet animal and clinical trials have
shown inconsistent, often less promising results. This is believed to be due to the
notoriously low bioavailability of oral RES (in some instances as low as 0%) (Yiu et al.,
2015; Sahebkar et al., 2015; Heebøll et al., 2016; Thazhath et al., 2016; Wong et al., 2016;
Zortea et al., 2016) most likely due to its poor metabolic stability which is a result of its
phase II metabolism (glucoronidation and sulfation) (Walle et al., 2004).

The good news:

In mice, it has been found that piperine (10 mg/kg) combined with resveratrol (100 mg/kg) results
in a 1544% increase in Cmax; whereas the degree of exposure (i.e. area under the curve
[AUC]) to RES was enhanced by 229% (Johnson et al., 2011).

So if Japanese Knotweed isn't working for you, or if you simply want to take less, it might be a good idea to add black pepper/piperine.

Piperine is really cheap to purchase actually.

Lol Bailey, yes you're right 😃.
I was trying to figure out why some things work for some people and not for others.
I think absorption is one of the reasons why.
Thank you for your kindness

I know they say to take black pepper extract with turmeric to increase absorption as well. Some are premixed.

yep interesting - ref absorption - i knew it was a fairly large molecule - so was expecting it to be low, but hadn't expected 0% - good sleuthing

perperine works by opening the tight junctions in the gut lining to allow bigger stuff through easier

i have always been a bit wary of these types of chemical because many of us with lyme have leaky gut symptoms too - and i thought it might worsen symptoms rather than help

but i agree this difference in absorption from individual to individual could well be/is likely one of the reason why some people seem to do well and others get nothing from it

esp if the leaky gut variable is in the mix - could be those folks get more out of the knotweed as well

by the way Buhners standard dose for knotweed root powder in lyme in his second edition book is much clearer - its a lot - 30g a day - his first book just talked about tablets or capsules

yep its interesting stuff rainy

i think the basic way the tight junctions work - is that in general - the larger molecules will not move across the tight junctions well - in an inverse relationship - so things with a molecular weight of 200+ will typically be poorly absorbed through the gut lining - (and for that matter other biological barriers in the body - blood brain barrier - blood testes barrier - placenta - etc etc ) whereas small molecules are typically absorbed easily

i think there is then overlaid over this some kind of transporter mechanisms by which the body is able to pull through nutrients and things that it wants and needs - and block others that it needs to limit eg toxins, salts etc etc

i suspect those of us with leaky gut symptoms will have increased symptoms with things like perperine as we are already getting too much stuff through the tight junctions than we should do - and opening them further i likely to be detrimental - but i have not put it to the test systematically

I wouldn’t worry about that in regards to knotweed. The whole herb is important. Resveratrol is just one constituent. I wouldn’t be surprised if the resveratrol in knotweed is more easily absorbed than an extracted version. I use knotweed powder mixed in water.