Cross-referencing clinical data
A pairing appears on this page only when a trial gave both ingredients together and measured the result. Buchu 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.
Buchu leaf and bearberry leaf are the two herbs most often paired in traditional urinary preparations across European and South African herbal practice. Both also carry dose ceilings, buchu because of pulegone and uva ursi because of hydroquinone exposure from arbutin. The pairing reflects tradition rather than a tested combination, and stacking two herbs with their own duration limits is not a neutral choice.
The two are combined by formulation convention in the urinary category rather than because a study tested them together. Their chemistry does not overlap much, since cranberry contributes A-type proanthocyanidins and buchu contributes a volatile oil and flavonoids. The combination is commercial practice.
Marshmallow root polysaccharides form a mucilage layer, and traditional practice pairs that with more pungent volatile-oil herbs. Buchu essential oil is irritating to mucous membranes at concentration, which is the practical reason for the pairing. Nothing here has been measured, so read it as formulation tradition.
Dandelion leaf and root have a long-standing traditional diuretic reputation and are routinely blended with buchu. Any additive effect on fluid loss also means an additive effect on potassium and sodium losses, which is the part usually left unsaid. Anyone taking a prescribed diuretic should raise the combination with their prescriber.
The non-volatile fraction of buchu leaf is dominated by flavonoid glycosides including rutin, diosmin and hesperidin. Adding a rutin supplement stacks onto a fraction the leaf already contributes, though at very different magnitudes. The leaf contributes far less rutin than a supplement dose does.
Pulegone occurs in both pennyroyal-type mint oils and in some buchu chemotypes, and it is metabolised to menthofuran and further to reactive intermediates by CYP450. Combining two pulegone-containing oils raises total exposure to the same metabolite. This is the single most important reason to know the chemotype of a buchu product before stacking essential oils.
Pulegone is bioactivated by CYP450 to menthofuran and onward to electrophilic intermediates that are conjugated with glutathione, and glutathione depletion is the recognised route to liver injury from high pulegone exposure. NAC supplies rate-limiting cysteine for glutathione synthesis, which is why it is the standard antidote in pennyroyal oil poisoning. Naming this is a caution about the herb, not a suggestion that NAC makes high-dose buchu oil sensible.
Silymarin has documented effects on CYP450 activity, and pulegone toxicity depends on CYP-mediated bioactivation, so the interaction could push in either direction depending on which enzymes are involved. Nobody has measured it. The reason to name it is that the direction is unknown, which is not the same as absent.
Nothing specific on file for Buchu. Match the label to the daily amount above, and tell your doctor what you take.
Not medical advice. Show the label to your pharmacist.Read this carefully. These are 98 voluntary, unverified reactions reported to the FDA (openFDA). The number mostly reflects how popular Buchu is, not how risky it is. A report is not proof Buchu caused anything. It is a signal of what to watch for, nothing more.
Source: openFDA adverse-event reports. Voluntary reporting, not an incidence rate.
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.