Ranked by how strong the human evidence is — best supported first.
Best supportedIron statusNot enough evidence· no source yetThen, in order
A root used in Traditional Chinese Medicine, almost always within multi-herb formulas rather than alone. It contains coumarins including psoralens, plus ferulic acid and ligustilide.
Dong quai is marketed in the West as a single-herb menopause supplement, which is not how it is used traditionally and not how it has been studied. The one placebo-controlled trial of dong quai alone found no effect on hot flushes or on endometrial thickness. Its coumarin content creates a real anticoagulant interaction, and its psoralens cause photosensitivity.
The amounts, forms and durations published trials of Dong quai actually administered.
These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.
Studied for Menopausal symptoms
3–4.5 g
Dried root extract, divided doses · 12–24 weeks
The single placebo-controlled trial of dong quai alone at this dose found no difference from placebo. Traditional use is inside formulas where other herbs contribute, so single-herb dosing has little basis.
This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.
Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.
None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.
No timing has been studied. Traditional decoctions are taken with or between meals according to the formula rather than the herb.
Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.
What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.
There is not enough human research to support dong quai for anaemia or blood-building, despite that being its traditional framing within Chinese formulas.
Not enough evidence. Not enough human research to say anything useful yet.
Evidence is limited for dong quai and hot flushes. The one placebo-controlled trial of the herb alone found no difference from placebo, and combination-formula trials cannot attribute effects to it.
Not enough evidence. Not enough human research to say anything useful yet.
Randomised controlled trial · Fertility and sterility · 1997 · PMID 9418683
Randomised controlled trial · Clinical and experimental obstetrics & gynecology · 2003 · PMID 14664413
Deep research mode adds each paper’s own conclusion and stated limitations.
Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.
Interaction
Interacts withWarfarin, direct oral anticoagulants, aspirin, antiplatelet drugs
Dong quai contains coumarin derivatives, and case reports describe markedly raised INR and bleeding in people taking it with warfarin. It should be avoided with anticoagulants and stopped well before surgery.
Worth knowing
Furanocoumarins in dong quai cause photosensitivity and, with sun exposure, phototoxic skin reactions. It also raises theoretical concern about skin cancer risk with prolonged use and UV exposure.
Avoid
Dong quai has uterine-stimulant activity and traditional use affecting menstruation. It should not be used in pregnancy, and it is generally avoided during heavy menstrual bleeding.
Worth knowing
Some laboratory work suggests oestrogen-like activity, so it is generally avoided in breast, uterine and ovarian cancer and in endometriosis.
Worth knowing
Dong quai usually arrives as part of an imported Chinese formula, a product category with documented heavy-metal contamination and, in some cases, undeclared pharmaceuticals.