Cross-referencing clinical data
A pairing appears on this page only when a trial gave both ingredients together and measured the result. Fireweed 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.
Fireweed contributes oenothein B, a macrocyclic ellagitannin with documented enzyme-inhibiting activity in laboratory work. Beta-sitosterol is a plant sterol studied separately for urinary flow measures. Neither has been tested against the other or in combination in a controlled human trial. The pairing rests on shared traditional use plus non-overlapping mechanism.
Polyphenols of the tannin class chelate divalent metals including zinc through their multiple adjacent phenolic hydroxyls. That is settled coordination chemistry and it applies to any high-tannin botanical. The practical answer is spacing the two by a couple of hours rather than avoiding either. Size of the effect for fireweed specifically has not been quantified.
Ascorbic acid is the standard countermeasure to polyphenol inhibition of non-heme iron, working by reducing ferric to ferrous iron and forming a soluble complex that resists tannin binding. If a tannin-rich herb and an iron source have to be taken together, ascorbate is the lever that exists. It does not fully cancel the effect at high tannin loads.
Phytochemical work on Epilobium angustifolium consistently reports flavonol glycosides of quercetin, myricetin and kaempferol alongside the ellagitannins. Adding isolated quercetin therefore stacks rather than complements. Both are conjugated by the same phase two enzymes, so clearance capacity is shared as well.
Protein precipitation is the defining chemical property of tannins and it is what makes strong tea taste astringent. Enzyme preparations are proteins and are subject to the same binding. Taking a high-tannin herb in the same swallow as a protease or amylase blend can reduce the enzyme activity that survives to work. Separate them by an hour.
Tannins form insoluble complexes with proline-rich and other proteins, which is why astringent plants reduce protein digestibility in feed studies. A concentrated fireweed extract in the same shake as a protein isolate will bind some of it. At normal supplement doses the amount involved is small relative to a protein serving. It matters more for the herb's own astringency than for the protein total.
Nothing specific on file for Fireweed. 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.