Yerba mate can relieve fatigue and help with weight loss, according to proponents of this herbal tea. However, these claims are not supported by scientific research, and long-term consumption of yerba mate in large amounts may increase the risk of cancer of the mouth, esophagus and lungs, states Mayo Clinic.
Yerba mate contains caffeine and other stimulants and is used to alleviate depression and chronic fatigue syndrome. However, drinking the tea has side effects such as insomnia, nervousness, nausea and high blood pressure, according to WebMD. Early research suggests that yerba mate is helpful in regulating cholesterol in patients taking statin drugs, and daily consumption of this beverage may reduce the risk of osteoporosis.