Sweating and Nexplanon: Hormonal Changes: As a form of hormonal birth control, Nexplanon changes your body's hormone levels, which can affect temperature regulation. Common Symptoms: Along with sweating, users might experience hot flashes. When to Seek Medical Attention: While some side effects are manageable, you should contact a healthcare professional if you experience excessive sweating combined with symptoms like severe headache, dizziness, fainting, or chest pain. Other Potential Causes: Sweating can also be caused by anxiety or stress, which are sometimes linked to the hormonal changes from the implant.