I was using this dihydroquercetin (DHQ) product:
Swanson Ultra Russian Rejuvenator | 60 Capsules - £14.35
I believe this form of DHQ is a molecular complex of dihydroquercetin and vitamin C (based on the Russian drug Ascovertin). I am not sure why they complex DHQ with C, but it may be to enhance DHQ absorption and bioavailability.
DHQ by the kilo:
http://www.balinvest.lv/shop/
I understand from
@halcyon that Dr Chia is now recommending DHQ for antiviral purposes. DHQ is a potent antiviral, as effective as ribavirin for coxsackievirus B4.
However, the problem with DHQ is that its oral absorption is only a measly 0.49% (see
this study; note that DHQ is also called taxifolin). Though I
read that oral DHQ absorption goes up to 36% if dissolved in lipid solution. So when I took my DHQ, I dissolved the powder in heated coconut oil first. I am hoping that will get me 36% absorption (though one would really need to explore which oils or lipids are best suited to promoting DHQ oral absorption).
From the
CVB4 study, I worked out you would want a human injectable dose of around 500 mg DHQ daily; this is equivalent to the study's intraperitoneal dosing protocol for mice. Now if we assume 36% absorption in lipid solution (like coconut oil), that corresponds to a human oral dose of around 1400 mg of DHQ in lipid solution.
My problem with DHQ is that even at oral doses of just 180 mg, DHQ causes me a lot of brain overstimulation. This overstimulation I think is likely due to adenosine receptor antagonism: quercetin is an adenosine receptor antagonist, and I am guessing DHQ, which is related to quercetin, may be also. The stimulant caffeine works by adenosine receptor antagonism.
The brain overstimulation was too strong for me, so I stopped taking DHQ. I am trying to find a workaround for this, to prevent the adenosine receptor antagonism and the resultant overstimulation caused by DHQ.