Dichroa.
A Chinese herb whose root alkaloids block a protein-building enzyme that collagen depends on. That chemistry became a drug, and the raw herb is emetic enough to be practitioner territory.
- Category
- Herb
What Dichroa is, and what it does.
- Does it work
- This suits a trained practitioner working within a traditional formula, not a shelf product. Its chemistry sits in the pharmaceutical column rather than the nutritional one.
- How much to take
- No supplement amount is on record and none should be picked. The margin between an acting amount and a vomiting one is narrow, which is why dosing here belongs to a clinician.
- Time to feel it
- The emetic effect of the raw root arrives quickly rather than building over days. Nothing else about a time course is documented for supplemental use.
- The first dose
- Day one with the raw root is dominated by nausea and vomiting at meaningful amounts. That is the documented first impression, and it is why the plant was set aside.
- With regular use
- Nobody has studied weeks of daily intake in people, and the herb was moved out of general use long before that question was asked.
- How well tolerated
- This is the strongest caution here. The raw alkaloid is strongly emetic and can injure the gut lining, with a narrow margin. Practitioner supervision is not optional.
- How it feels
- Unpleasant. Nausea is the defining experience of the raw root, which is precisely why the modified derivative was made in a lab instead.
- The overlooked benefit
- Because collagen is unusually rich in proline, blocking proline loading onto its transfer RNA slows collagen type I synthesis. That is the basis of the derivative's pharmacology.
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.
- Inhibition of prolyl-tRNA synthetaseIn vitro study
- Suppression of collagen type I synthesisAnimal study
- Activation of the amino acid starvation response through GCN2In vitro study
- Emetic effect of the natural alkaloid with a narrow marginNarrative review
Why these belong in the same formula. Each row says what the basis is, from settled biochemistry through to a trial that measured the pair.
Febrifugine and its derivative halofuginone block the proline binding site of prolyl-tRNA synthetase, which is what triggers the amino acid starvation response downstream. Adding proline competes for that same site, and the same is true in the other direction. This is the cleanest mechanistic interaction the plant has and it is well characterised at the enzyme level. It also means proline intake is a variable that changes what the alkaloid does.
Chang shan is notoriously emetic, and classical practice pairs it with ginger or processes it with ginger juice for exactly that reason. The pairing is a preparation convention with a long record of use rather than a measured pharmacological interaction. It does not remove the underlying toxicity of the alkaloids. Read it as historical practice, not as a way of making the herb tolerable.
Licorice appears in most classical formulas that contain harsh alkaloid-bearing herbs, where its stated role is to moderate the formula. That is a compositional convention from the tradition, not a demonstrated pharmacokinetic effect. Licorice also carries its own mineralocorticoid-like activity at sustained intakes. The combination is worth naming because it is common, not because it is validated.
Ascorbate is a routine antioxidant in liquid botanical extracts, where it slows oxidative degradation of sensitive constituents during storage. That is a shelf-life function, not a biological interaction with the alkaloids. It says nothing about what happens after ingestion. The pairing is formulation practice.
Nothing specific on file for Dichroa. 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 Dichroa actually does.
Dichroa's main active compounds are febrifugine and isofebrifugine, concentrated in the root.
Febrifugine and a related derivative block a specific enzyme, which stalls the building of proteins that need the amino acid proline and triggers a cellular starvation response.
Febrifugine strongly triggers vomiting, and there's only a narrow gap between an active dose and one that causes vomiting and gut injury, which is why the natural compound was abandoned in favor of modified derivatives.
The derivative halofuginone is a licensed veterinary drug and an investigational human drug, which puts this chemistry squarely in the pharmaceutical category rather than the nutritional one.
Where Dichroa comes from.
A Chinese herb whose active chemistry turned out to be strong enough to become a drug. It also makes people vomit hard, which is why the plant itself was dropped in favour of a modified version made in a lab. This is not a general-use supplement ingredient, and it belongs in a practitioner's hands rather than a shelf.
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.
Roots of a Hydrangeaceae shrub grown in southern China and Southeast Asia, harvested from plants several years old.
Roots are washed, sliced and dried. Traditional processing soaks or fries the slices with ginger juice before use.
Traditional use is a water decoction. Analytical and industrial routes use acid or alcohol extraction to recover the alkaloids.
The alkaloids are separated by pH-driven partition between aqueous and organic phases, then crystallised.
Where standardisation happens at all it is by chromatographic quantification of febrifugine and isofebrifugine.
Sold as cut root or granule for practitioner formulas. The isolated derivative halofuginone is a separate regulated substance.
The forms it comes in.
The essence, in one line each.
- Reported antiparasitic activity of Dichroa febrifuga preparations against coccidial infection in a veterinary setting.Animal study. Guo et al., 2025 (Frontiers in Veterinary Science). PMID 41550535 ↗
- Reported that halofuginone, a synthetic derivative of the Dichroa alkaloid febrifugine, reduced inflammatory and proliferative changes in pulmonary vasculature by acting on TGF-beta signalling.Animal study. Wang et al., 2025 (Scientific Reports). PMID 39880976 ↗
These are the studies our verdict leans on, chosen from the 2 we read for Dichroa. The full linked list is below.
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.