Cross-referencing clinical data
A pairing appears on this page only when a trial gave both ingredients together and measured the result. Douglas Iris has none that clears that bar.
Stitching two separate single-ingredient studies into a pairing is the one thing this engine will not do. When a study of the combination itself holds up at source, it lands here with its citation.
No invented synergy. Where actives were studied on their own rather than together, the record shows each on its own evidence, never a combined effect no trial measured.
Research strength. Research strength says how much work stands behind the combination. It is never a product score.
Independent record. Every finding is cited to a named trial, dated, and never written by the brand.
20 pairings are live across the library today. Checked 20 July 2026.
No study gave these as a pair, so they are not in the card above. But the reason they belong together is settled biochemistry, not a guess, so it is worth knowing.
Iris rhizome isoflavonoids and quercetin are both handled by the same intestinal and hepatic UGT and SULT conjugating enzymes. When two flavonoid loads arrive together, they compete for that finite conjugating capacity, which can raise the free fraction of either one. This is a pharmacokinetic interaction, not a benefit, and it has not been measured for this species specifically. Read it as a reason to space large flavonoid doses rather than as a pairing to seek out.
Activated charcoal binds a wide range of small organic molecules in the gut lumen, including plant phenolics and alkaloids. Taken in the same window, it lowers how much of any botanical preparation reaches the bloodstream. Separation by two hours or more is the usual formulation practice. The same is true in the other direction for bentonite clay and other binders.
Ascorbate reduces phenoxyl radicals formed when plant polyphenols quench an oxidant, returning the polyphenol to its reduced form. That recycling is well characterised in solution and in food matrices. Whether it changes anything measurable in a person taking an iris preparation has not been tested. This is chemistry, not a clinical outcome.
Nothing specific on file for Douglas Iris. Match the label to the daily amount above, and tell your doctor what you take.
Not medical advice. Show the label to your pharmacist.FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement regimen.