Thuja is the name of a genus of evergreen tree native to the United States. In homeopathy, thuja is used to care for many different conditions, such as skin problems, menstrual issues, respiratory illnesses, and urogenital problems. Common conditions like headaches, toothaches, acne, bacterial infections, and hair loss may also benefit from the use of thuja. Mental health problems like depression and stress can also be treated with this homeopathic remedy.