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Sweet Clover


Sweet clover is an herb with yellow flowers. It has been used to improve the flow of blood and of urine. Sweet clover can be taken as a pill or extract.


There are no advised doses for sweet clover.

What Research Shows

May Be Effective

  • Diabetic cystoid macular edema without macular thickening —may preserve retinal sensitivityA1, A2

Not Enough Data to Assess

  • Postoperative ecchymosis and edema B1

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

Safety Notes

It is likely safe for most adults to take sweet clover in small doses for a short time. Liver damage and bleeding problems may happen with large amounts. Not enough studies have been done to say whether it is safe to use for a long period. It is also not known whether it is safe to take by women who are pregnant or breastfeeding.


Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse such as:

  • People taking blood thinners should talk to their doctors before taking sweet clover. It may increase the risk of bleeding.


A. Diabetic Cystoid Macular Edema Without Macular Thickening

A1. Forte R, Cennamo G, et al. Combination of flavonoids with Centella asiatica and Melilotus for diabetic cystoid macular edema without macular thickening. J Ocul Pharmacol Ther. 2011 Apr;27(2):109-113.

A2. Forte R, Cennamo G, et al. Long-term follow-up of oral administration of flavonoids, Centella asiatica and Melilotus, for diabetic cystoid macular edema without macular thickening. J Ocul Pharmacol Ther. 2013 Oct;29(8):733-737.

B. Postoperative Ecchymosis

B1. Xu F, Zeng W, et al. The efficacy of melilotus extract in the management of postoperative ecchymosis and edema after simultaneous rhinoplasty and blepharoplasty. Aesthetic Plast Surg. 2008 Jul;32(4):599-603.

C. Safety

C1. Hogan RP 3rd. Hemorrhagic diathesis caused by drinking an herbal tea. JAMA. 1983 May 20;249(19):2679-2680.

C2. Heck AM, DeWitt BA, et al. Potential interactions between alternative therapies and warfarin. Am J Health Syst Pharm. 2000 Jul 1;57(13):1221-1227.

C3. Tamura S, Warabi Y, et al. Severe liver dysfunction possibly caused by the combination of interferon beta-1b therapy and melilot (sweet clover) supplement. J Clin Pharm Ther. 2012 Dec;37(6):724-725.

Last reviewed July 2019 by EBSCO NAT Review Board Eric Hurwitz, DC  Last Updated: 3/27/2020