Java Brucea.
Java brucea is the bitter dried fruit of a Southeast Asian shrub, used in Chinese practice as ya dan zi under a practitioner rather than picked off a shelf by yourself.
- Category
- Herb
What Java Brucea is, and what it does.
- Does it work
- This is practitioner material. The people it suits are those working with a clinician who knows the plant, the plant part and the amount being given.
- How much to take
- No daily amount is on record. Traditional internal amounts are small and set by a practitioner, and we are not going to print a number nobody has established.
- Time to feel it
- Nobody has measured a timeline for oral use. Bitterness arrives immediately and stomach irritation is the earliest documented effect.
- The first dose
- The taste is overwhelmingly bitter. Nausea or stomach upset on the first day is the plant signalling the amount was too high, and that is worth acting on.
- With regular use
- No long-term human data exists for oral use, and liver enzyme elevation is documented with the crude fruit, so this is not material for extended self-directed use.
- How well tolerated
- Documented effects include gastrointestinal irritation, vomiting and raised liver enzymes, and the gap between an active and a harmful amount is small. Use only with a clinician.
- How it feels
- Intensely, memorably bitter, which is what quassinoids taste like. Nothing about the experience is pleasant, and that is consistent with the traditional record.
- The overlooked benefit
- The seed oil and the water or alcohol extract are chemically different: quassinoids partition into the polar extracts, so a label giving only the plant name tells you very little.
The proof, claim by claim.
These words describe the research, not the molecule's worth. Research strength is how much work stands behind one claim, and it is never a product score.
- protein synthesis inhibition by quassinoidsIn vitro study
- traditional use of the dried fruit in Chinese herbal practiceNarrative review
- gastrointestinal irritation and liver enzyme elevation with the crude fruitNarrative review
No pairing data for Java Brucea yet.
Nothing on file for Java Brucea, either from a combination trial or from settled biochemistry. When either lands, it appears here with its source.
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, each shows 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.
24 pairings are live across the library today. Checked 25 August 2026.
Nothing specific on file for Java Brucea. Match the label to the daily amount above, and tell your doctor what you take.
Not medical advice. Show the label to your pharmacist.What Java Brucea actually does.
Java brucea is a shrub whose dried fruit is used in traditional Chinese medicine.
The main compounds in this plant are intensely bitter quassinoids, and they're responsible for both whatever biological activity the plant has and its toxicity.
These compounds block protein production inside cells in a way that isn't specific to any one cell type, which is why killing cells in a lab dish doesn't translate into something safe to take orally, and why the margin between an effective and a harmful dose is narrow.
An oil emulsion made from this plant is used as a regulated injectable drug in China under medical supervision in certain oncology settings, and that's a different category from a self-chosen oral supplement, so evidence for one doesn't carry over to the other.
Where Java Brucea comes from.
Java brucea is the dried fruit of a Southeast Asian shrub, known in Chinese medicine as ya dan zi. It is genuinely biologically active, which is exactly the problem: the compounds in it shut down protein production in cells generally, not selectively, so the gap between a dose that does something and a dose that does harm is small. In China a purified oil version exists as a hospital injection given by doctors. That is not the same thing as a capsule you buy yourself, and the evidence for one does not carry over to the other. This is not a self-directed supplement.
Made from a plant. What ends up in the capsule tracks the harvest, so batch testing and a stated marker matter more here than with a made molecule.
Dried ripe fruit of a shrub or small tree native to Southeast Asia, southern China, India and northern Australia. Collected in autumn when ripe, dried, and traded under the name ya dan zi.
Two divergent routes exist in Chinese pharmaceutical manufacture. Pressing or extracting the seed gives an oil used to make a regulated injectable emulsion. Polar solvent extraction of the fruit concentrates the quassinoid fraction.
Pharmaceutical preparations are controlled against bruceine content by chromatography, which exists precisely because the active compounds are toxic at modest exposure and need a specification.
The recognised finished forms are a hospital-administered oil emulsion for injection and practitioner-directed traditional preparations. There is no established over-the-counter oral supplement form with a defined dose or safety margin.
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.