Sometimes, when ephedra is taken with plants containing a lot of caffeine (such as melon seeds), it will lead to sudden death such as stroke, spasm and high blood pressure. Herbs containing a lot of caffeine include guarana seeds, kola nuts, tea trees (used for jasmine tea, green tea and other teas sold) and coffee beans. These herbs are widely planted all over the world, and they are very popular substances to lose weight, because it is said that caffeine can promote metabolism. Excessive intake of caffeine can lead to anxiety, insomnia, arrhythmia, addiction and even death in hypertensive patients.