Supplement analysis backed by scientific evidence · PT

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Limited evidenceImmunity

Forsythia (Lian Qiao)

A core cooling herb in Chinese medicine for sore throat and fever. It has never been tested alone in a clinical trial — all human data come from multi-herb formulas in which forsythia is one ingredient among a dozen.

Evidence last reviewed: August 2026

What the science says

  • Studied only inside multi-herb formulas Limited evidence

    Forsythia is one of more than ten ingredients in Lianhua Qingwen. A meta-analysis of randomized trials in COVID-19 reported improvements in symptom resolution rates with the formula, but nothing in that data can be attributed to forsythia specifically, and the included trials were mostly open-label and conducted in China.

  • Antiviral effects are cell-culture level Limited evidence

    Forsythoside A isolated from Forsythia suspensa reduced influenza A virus M1 protein in infected cells. In-vitro antiviral activity of an isolated compound does not establish that swallowing the herb affects a real infection.

Dosage & safety

Studied doseNo supplement dose has been validated. Traditional decoction use is 6–15 g of dried fruit per day, usually within a formula.
SafetyMild gastrointestinal upset and loose stools are the commonest complaints. Traditionally avoided in people with weak digestion or chronic diarrhoea. Not studied in pregnancy. Multi-herb Chinese formulas vary widely in composition and quality — buy only from manufacturers that publish testing.

Scientific references

Where to buy

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