There are many traditions related to worship in our Hindu religion like tying the thread of worship, offering fruits, applying tilak etc. on the wrist during worship. No puja-prayer begins without wearing tilak. According to beliefs, a without tilak forehead is not considered auspicious. Mostly kumkum tilak is applied on the forehead during worship. Tilak is applied on the frontal or as a small dot between the two eyebrows. From the scientific point of view, applying tilak keeps peace, temperature and coolness in the mind. There is a balance of chemicals in the brain called seratonin and betaendorphine. Increases the strength and does not cause mental exhaustion disorder.
But most of Kumkum's tilak is used in worship. The reason behind this is that Kumkum is turmeric powder. In which, mix lemon juice becomes red in color. According to Ayurveda, Kumkum is the best medicine for skin purification. Applying its tilak does not cause attenuation of brain fibers. That is why tilak of Kumkum is applied in worship.