During excretion they irritate the kidneys and the sweat-glands, and thereby increase the excretion of urine and of sweat.
Use a water-based product; it will let your sweat glands do their work as it decreases your risk of squamous-cell carcinoma.
The forehead has much more sweat glands than the back of your arm.
It also stimulates the sweat glands and increases blood circulation to underlying organs and tissues in the body.
During adolescence the hormonal changes will also affect the sweat glands.