There have been no studies to prove that black horehound provides benefit and causes no harm. Its effectiveness in relieving nausea, vomiting, and digestive spasms has not been clinically demonstrated. Some studies show that the plant may have some sedativesedativean agent that induces sleep, relaxes, and reduces tension properties.
Black horehound is not commonly used due to its strong odour.
Contact your health care provider if your symptoms worsen or persist.
Information on black horehound side effects is limited. Contact your doctor as soon as possible if you experience breathing problems, chest or throat tightness, chest pains, skin rash, or hives.
Drug interactions associated with the use of black horehound products include iron supplements and sedatives. Black horehound can prevent iron absorption. Also, black horehound combined with other sedatives can have an additive effect and cause further sedation.
Avoid black horehound if you have a known allergy to it or if you are allergic to any of the ingredients found in the product formulation.
Pregnant and breast-feeding women and children should not take black horehound.
Before taking any new medications, including natural health products, speak to your physician, pharmacist, or other health care provider. Tell your health care provider about any natural health products you may be taking.