The human skin has a natural defense mechanism to protect itself from the harmful effects of the sun's ultraviolet (UV) radiation. When exposed to sunlight, the skin produces a pigment called melanin. Melanin not only gives the skin its color but also provides some level of protection against UV rays by absorbing and dissipating the radiation. This process is what we commonly refer to as tanning.
However, there is a limit to how much your skin can tan, and this limit varies from person to person depending on their skin type, genetics, and sun exposure habits. It's essential to understand that your skin does not tan endlessly, and there are several factors that come into play when it comes to reaching this tanning limit.