Tanmaxxing, the practice of getting as tanned as possible as fast as possible, has been gathering momentum on TikTok. It involves timing walks or sunbathing to the peak UV hours of the day, and in some corners it involves rubbing carrot oil on the skin in the belief that beta carotene will deepen the colour.

Evan Rieder, a dermatologist and psychologist based in New York, told ELLE the pursuit of a tan often has very little to do with how anyone looks.

Skin has its own stress system

This is the part most people do not know. Skin is unusual among organs in having its own stress axis, separate from the whole body response that raises your blood pressure and shifts your hormones when you are frightened.

When ultraviolet light hits skin, a molecule is broken down into several particles. One is a melanocyte stimulating hormone, which is what actually tans you. Another is beta endorphin, the same molecule people mean when they talk about an endorphin rush. In certain people, Rieder says, that reward loop is enough to drive genuinely compulsive behaviour.

Is it really an addiction

Not a formal diagnosis, and that is exactly why it is interesting. Rieder describes it as an active area of debate in psychiatry, complicated by the fact that people who tan compulsively almost never present for help, because they do not experience it as a problem.

He notes he rarely sees these patients himself and follows the behaviour mostly through what surfaces online. What social media has changed, in his view, is scale. A habit that used to be private, carried out alone in a tanning salon, is now performed for an audience and copied.

The culture part

Whether a tan is desirable at all is heavily dependent on where you grew up. In much of the West tanned skin has read as health and leisure for decades. In other countries it reads very differently, partly because of a stronger public understanding of what ultraviolet light does to skin, and partly because in some societies a tan has historically signalled outdoor labour.

What it costs

The long term effects are not in dispute. UVA penetrates deeply and denatures collagen, which is what accelerates visible ageing, and the rates of both skin ageing and skin cancer among heavy tanners are high. Melanoma risk rises with exposure.

Rieder's framing is the useful one. The tan is short. The bill is long.