How do deodorants primarily exert their action?

Deodorants primarily exert their action by controlling bacteria responsible for body odour. The human body produces sweat, which itself is mostly odorless. However, when sweat comes into contact with the skin, certain bacteria break it down, leading to the production of odorous compounds. Deodorants work by introducing antimicrobial agents that inhibit the growth of these bacteria, thereby reducing the formation of body odour.

This mechanism is crucial since the unpleasant smell associated with sweating is largely a result of bacterial activity rather than the sweat itself. By specifically targeting the bacteria that contribute to odour, deodorants effectively manage the scent without altering bodily functions such as sweating. Other options, such as constricting sweat glands or changing the skin's pH, do not directly address the underlying cause of body odour, which is the bacterial breakdown of sweat. Similarly, increasing skin temperature does not play a role in the effectiveness of deodorants for odour control.