Can coffee grounds be used to stop bleeding? The answer might surprise you

One of the main reasons Americans wind up in the ER is for evaluation and treatment of a laceration, a deep cut or tear in the skin. In fact, people with cuts account for about 8% of all ER visits; that’s 9 million lacerations treated annually in the U.S.

A bleeding wound can be especially traumatic for people who are unable to control it at home by applying pressure or placing a bandage. This is further complicated by the fact that millions of Americans are on blood thinners to prevent a stroke or treat a blood clot. These blood thinning effects are not easily reversed, and patients with a seeming innocuous injury could require a high level of care in the ER.

It’s not a surprise that my patients have tried a variety of home remedies to control bleeding before deciding to come to the ER. One of the most interesting ones I’ve seen is packing coffee grounds into a bleeding wound.

The patient could not give a reason for why he thought it worked, only that he had heard anecdotally from family members that he should try it. And sure enough, by the time I saw him in the ER, the bleeding had stopped. Scientific studies or clinical trials exploring the benefit of using coffee grounds to control bleeding are limited. Compared with other medical myths and home remedies, I could not find a significant cultural or historical impetus for its use either, but it does appear as a local practice for wound healing in areas of Southeast Asia.

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So why would coffee grounds help control bleeding? The caffeine in coffee is a known vasoconstrictor, or something that has the ability to reduce blood flow. In the ER, we inject the powerful vasoconstrictor epinephrine along with a local anesthetic lidocaine to control bleeding in a wound. One study I found did demonstrate a reduction in blood flow to the fingertips of those who drank coffee. But it’s unclear if the caffeine in topically applied coffee grounds would exert the same vasoconstricting effect.

It’s more likely that control of bleeding is achieved by the packing of the wound directly with the coffee grounds. This is similar to what we advise people to do at home and what we would do in the ER; direct firm pressure with sterile gauze packed into the wound for 15 straight minutes. It’s also possible that the coffee grounds absorb some of the oozing and give the appearance that bleeding is controlled.

So, should you pack a bleeding wound with coffee? While the benefits of drinking coffee regularly continue to grow – decreased risk of colon cancer, heart disease for example – I would not recommend putting coffee grounds or other unsterile substances into the wound.

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The primary goal is high-pressure irrigation to remove dirt and other foreign bodies to minimize infection, followed by direct firm pressure for 15 minutes. For smaller cuts and wounds, that should be enough. Once the bleeding is stopped, inspect the wound. If superficial, place antibiotic cream over the cut and secure it with a bandage.

When should you seek medical attention at the ER? If the wound is deep or contaminated, bleeding is not controlled, or if you take a blood thinner you might need imaging, suture repair, or help to reverse your bleeding. Those who are diabetic or immune-compromised, have a high-risk area wound to the face, hands or feet, or have a wound from a bite probably will need antibiotics. It’s also a good idea to get a tetanus shot if it has been more than five years since your last vaccine.

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Michael Daignault, M.D., is a board-certified ER doctor in Los Angeles. He studied Global Health at Georgetown University and has a Medical Degree from Ben-Gurion University. He completed his residency training in emergency medicine at Lincoln Medical Center in the South Bronx. He is also a former United States Peace Corps Volunteer. Find him on Instagram @dr.daignault