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Scientific Name(s): Forsythia suspensa (Thunb.) Vahl
Common Name(s): Forsythia, Golden bells, Lian qiao, Weeping forsythia

Medically reviewed by Last updated on Sep 13, 2022.

Clinical Overview


Clinical trials are lacking to support a place in therapy for forsythia. Research interest focuses on chemotherapeutic applications.


There are no recent clinical studies of forsythia to provide a basis for dosage recommendations.


Contraindications have not yet been identified.


Documented adverse effects. Uterine stimulant, emmenagogue. Avoid use.


None well documented.

Adverse Reactions

Forsythia is contraindicated in pregnancy.


Information is limited.

Scientific Family

  • Oleaceae (olives)


F. suspensa is an attractive deciduous shrub native to China. It is often grown ornamentally in the United States for its bright yellow flowers that appear in early spring. There are numerous horticultural varieties that are vegetatively propagated. The Chinese drug is obtained in the fall from the ripe fruits of the cultivated plant. The related species F. viridissima and F. koreana also are used medicinally.


Forsythia fruits are widely used in Chinese traditional medicine for antipyretic and anti-inflammatory activity in the treatment of bacterial infections and upper respiratory ailments. They are commonly combined with honeysuckle flower (Lonicera) and other ingredients. Forsythia fruits are also reputedly used as a diuretic and as a cardiovascular tonic.


Lignans, such as phylligenin and pinoresinol, and their glucosides are major constituents of F. suspensa fruits, while the other species contain related compounds.Nikaido 1981 Caffeic acid glycosides with variation in the number of sugars include forsythiasideNishibe 1982 suspensasideNishibe 1982 and a number of forsythosides.Endo 1982 The reduced cyclohexylethane derivatives rengyol, rengyoxide, and rengyoloneEndo 1984 and their glycosides (rengyosides A-CSeya 1989 and forsythensides A and BMing 1998) have been reported. The distribution of various phenolics among 7 different species of forsythia in leaves and fruits has been studied.Kitagawa 1984, Kitagawa 1988 Rutin is the major flavonoid of all 7 forsythia species.Kitagawa 1988 Caffeic ester glycosides from related genera of the Oleaceae have been compared.Andary 1992 Several triterpenes have been isolated from the fruits as well.Ozaki 2000 An HPLC assay for major forsythia phenolics has been published.Cui 1992 The essential oil composition of the fruits has been studied.Xu 1994

Uses and Pharmacology

Antimicrobial activity

Animal data

Antimicrobial effects, including antiviral activity, have been reported on screening and in vitro studies.Chen 2009, Endo 1982, Endo 1981, Ko 2006, Kong 2007, Li 2014, Nishibe 1982, Zhang 2010

Clinical data

Research reveals no clinical data regarding the use of forsythia as an antimicrobial agent.


Animal data

Extracts of forsythia have been studied in human tumor cell lines and rodent studies.Ge 2016, Shin 2015, Zhao 2015

Clinical data

Research reveals no clinical data regarding the use of forsythia in cancer.

Other uses

Antioxidant activity against LDL oxidation has been demonstrated in vitro.Chang 2008, Chen 1999

Anti-inflammatory effects were reported on in older in vitro studies.Heilmann 2000, Kim 2000, Kimura 1987, Ozaki 2000, Ozaki 1997

The flavonoid rutin was found to be the active anti-emetic constituent of forsythia fruits using an experimental chicken model of emesis.Yang 1999


There are no recent clinical studies of forsythia to provide a basis for dosage recommendations.

Pregnancy / Lactation

Documented adverse effects. Uterine stimulant, emmenagogue. Avoid use.McGuffin 1997


None well documented.

Adverse Reactions

Use during pregnancy is strictly contraindicated because of its emmenagogue/uterine stimulant properties.


Information is limited. F. suspensa extracts were not mutagenic in Ames tests; however, the incidence of chromosomal aberrations and micronucleated polychromatic erythrocytes in bone marrow of treated mice were somewhat elevated.Yin 1991

Index Terms

  • Forsythia koreana
  • Forsythia viridissima



This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this product. This information does not endorse this product as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this product. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this product. This information is not specific medical advice and does not replace information you receive from your health care provider. You should talk with your health care provider for complete information about the risks and benefits of using this product.

This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.

Andary C, Tahrouch S, Marion C, Wylde R, Heitz A. Caffeic glycoside esters from Jasminum nudiflorum and some related species. Phytochemistry. 1992;31(3):885-886.1368040
Chang MJ, Hung TM, Min BS, et al. Lignans from the rruits of Forsythia suspensa (Thunb.) Vahl protect high-density lipoprotein during oxidative stress. Biosci Biotechnol Biochem. 2008;72(10):2750-2755.18838794
Chen C, Chen HY, Shiao MS, Lin YL, Kuo YH, Ou JC. Inhibition of low density lipoprotein oxidation by tetrahydrofurofuran lignans from Forsythia suspensa and Magnolia coco. Planta Med. 1999;65(8):709-711.10630110
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Endo K, et al. Structures of rengyol, rengyoxide and rengyolone, new cyclohexylethane derivatives from Forsythia suspensa. Can J Chem. 1984;62:2011.
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Ko HC, Wei BL, Chiou WF. The effect of medicinal plants used in Chinese folk medicine on RANTES secretion by virus-infected human epithelial cells. J Ethnopharmacol. 2006;107(2):205-210.16621378
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Ozaki Y, Rui J, Tang YT. Antiinflammatory effect of Forsythia suspensa Vahl. and its active principle. Biol Pharm Bull. 2000;23(3):365-367.10726898
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Seya K, et al. Structures of rengyosides A, B and C, three glucosides of Forsythia suspensa fruits. Phytochemistry. 1989;28:1495.
Shin HS, Park SY, Song HG, Hwang E, Lee DG, Yi TH. The androgenic alopecia protective effects of Forsythiaside-A and the molecular regulation in a mouse model. Phytother Res. 2015;29(6):870-876.25808759
Xu Z, et al. Analysis of constituents of essential oil from the Forsythia suspensa (Thunb.) Vahl. Natural Product Res Dev. 1994;6:14.
Yang Y, Kinoshita K, Koyama K, et al. Novel experimental model using free radical-induced emesis for surveying anti-emetic compounds from natural sources. Planta Med 1999;65(6):574-576.10483380
Yin X, Liu DX, Wang HC, Zhou Y. A study on the mutagenicity of 102 raw pharmaceuticals used in Chinese traditional medicine. Mutat Res. 1991;260(1):73-82.2027343
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Further information

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