What Happens in the Skin When It Tans?

The short answer

The skin contains pigment-forming cells called melanocytes. They produce melanin, the pigment that contributes to the colour of skin, hair and eyes.

When the skin is exposed to UV light, existing melanin can darken while the melanocytes are stimulated to produce and distribute more pigment. This is what gradually makes the skin browner.

The full change is not always visible immediately after a session. Some of the pigmentation shows quickly, while other colour develops over the following days.

Because different skin types respond differently, exposure schedules are available on site with recommended times for each skin type and sunbed. They serve as guidance when you choose a time that suits your individual circumstances. Read more about the sunbeds at Solportalen.

What is melanin?

Melanin is a natural pigment produced by melanocytes at the base of the epidermis, the outer layer of the skin.

The pigment is formed in small structures called melanosomes. These are passed on to the skin's most common cells, the keratinocytes, where the pigment is distributed through the epidermis.

People with different skin tones do not necessarily have dramatically different numbers of melanocytes. The differences mainly come down to:

• how much melanin is produced
• which type of melanin is formed
• the size and distribution of the melanosomes
• how long the pigment remains in the skin cells
• how the melanocytes respond to UV light

Skin tone and the ability to tan therefore cannot be explained by a single factor.

What happens when UV light reaches the skin?

Ultraviolet radiation is divided into UVA and UVB, among others. Both can influence the skin's pigmentation, but in partly different ways.

Sunbed light contains different proportions of UVA and UVB depending on the equipment and lamp configuration. The visible result is often a combination of existing pigment darkening and new pigment production being stimulated. See our different sunbeds and rooms.

Why does the colour develop gradually?

It is easy to judge a session by how the skin looks immediately afterwards. But the full pigmentation is not always visible straight away.

The faster pigment darkening may be noticeable early, while new melanin production develops gradually over the following days.

This means the skin can continue to gain colour even after the session has ended.

It is therefore sensible to let the skin show how the pigmentation develops before judging the next session length. A longer time straight away does not necessarily give a better or more even result.

Why do different people tan differently?

Our basic pigmentation is largely governed by genetic factors. Genes influence, among other things, which kind of melanin the body forms and how the pigmentation system responds to UV light.

Two important pigment forms are:

• eumelanin, which is brown to black
• pheomelanin, which is yellowish to reddish

People with a greater proportion of eumelanin generally have a darker base pigmentation and often develop colour more easily.

People with very fair or red-toned skin often produce less eumelanin and may get a lighter or more limited pigmentation.

Hair colour, eye colour and freckles can give some indication of the skin's pigmentation, but what matters most is how your own skin usually responds to UV light.

Skin types and individual tolerance

A common way to describe the skin's response to UV light is the Fitzpatrick skin type scale. It is based mainly on how easily the skin tends to redden and how easily it develops pigment.

The scale is a simplified tool and cannot predict every person's response exactly. It does, however, help explain why different people may need different session lengths.

Skin type is not only about how the skin looks, but also about how it usually responds to UV light.

Skin type is about response – not only appearance

It is not always enough to look at someone to determine how their skin responds to UV light.

Two people with a similar visible skin tone can respond differently depending on genetic variation, previous pigmentation, skincare, medication and other individual factors.

When assessing skin type it can therefore be more relevant to consider:

• How does the skin usually respond during the first strong spring or summer sun?
• How easily does it develop colour?
• Does the pigmentation come quickly or only after several sessions?
• Does the skin have many freckles?
• How long is it since it was last exposed?
• How did the colour develop after the most recent session?

A session length that has suited you before is not automatically right at every later visit. The skin's current pigmentation, the time since the last exposure and changes in medication or skincare can all affect the experience.

Why doesn't the same session length suit everyone?

A given time in a sunbed does not give exactly the same experience or result for every skin type.

Fairer skin can respond differently to more pigmented skin. Two people with a similar skin tone can also develop pigment at different rates.

Session length is influenced by, among other things:

• skin type and natural pigmentation
• how easily the skin usually develops colour
• how long ago the last UV exposure was
• existing tan
• which sunbed equipment is used
• the strength and composition of the lamps
• any medication
• the skin's current condition

It is therefore not particularly helpful to copy a friend's session length or assume that the same time suits everyone.

Tanning and reddening are different responses

A tan means the pigmentation has changed. Redness or irritation is a different type of response.

Skin that has had too much exposure can feel:

• warm
• tender
• tight
• irritated
• unusually sensitive
• red or changed in tone

Redness is not always equally visible on all skin tones. How the skin feels can therefore be at least as important as how it looks.

Wait before your next session if the skin still feels warm, tender or irritated. Give it time to return to its normal state before judging the next session. Read more before your visit.

Does a tan provide natural protection?

Melanin can absorb and scatter some UV light, which gives the skin a degree of natural protection.

Skin with a darker base pigmentation therefore often has a greater natural tolerance to reddening than very fair skin.

That protection is at the same time limited. A developed tan does not mean that session lengths should be increased quickly, or that the skin will respond the same way on every future occasion.

A so-called base tan should therefore be seen primarily as pigmentation, not as a reason to choose ever longer sessions.

Why is the colour sometimes uneven?

The skin is not identical across the whole body.

Pigmentation can be affected by:

• natural differences between skin areas
• previous exposure
• freckles and pigment spots
• scars
• hormonal factors
• cosmetics and skincare products
• how the light reaches the skin
• pressure points and body position
• the thickness of the skin
• the skin's cell renewal

Some parts of the body respond faster than others. The face, shoulders, arms and other areas often exposed to daylight can therefore take on a different tone to skin that is usually covered.

Body position and how the light reaches different parts of the skin can also affect how even the colour appears. See current prices.

Why does a tan fade?

The cells of the epidermis renew themselves continuously.

Melanin is largely held in keratinocytes that gradually move upwards through the epidermis. When the pigmented cells eventually leave the outermost layer of the skin and are replaced by new cells, the colour gradually becomes lighter.

How quickly a tan fades is influenced by, among other things:

• how much pigment has been formed
• how the pigment is distributed
• the skin's natural cell renewal
• base pigmentation
• continued exposure
• individual skin biology

How long the colour lasts therefore varies both between people and between different parts of the body.

Medication and light sensitivity

Medication and skincare products can affect sensitivity

Some medicines can make the skin more sensitive to UV light. The response may show up as unusually rapid redness, a rash, itching or changes in pigmentation.

Certain cosmetic products, perfumes and skin treatments can also affect how the skin responds.

1177, the Swedish national health guide, recommends that anyone using medication checks whether it can increase light sensitivity. Information may be found in the patient information leaflet. If you are unsure, ask at a pharmacy or contact a healthcare provider.

Refrain from UV exposure if a medicine, a treatment or a medical recommendation states that it should be avoided.

When might it be wise to wait before the next session?

It may be wise to wait if:

• the skin still feels warm, tender or irritated
• the skin responded more strongly than expected after the last session
• you are using a medicine that can increase light sensitivity
• the skin has recently been treated with a peel, laser or another treatment that can make it more sensitive
• you have an active rash or ongoing irritation
• you are unsure how the skin has responded

If you are unsure about your skin's condition or how a medicine affects light sensitivity, it is sensible to find out before your next session. Contact us if you have questions.

More colour does not always mean a better result

It is easy to turn tanning into something to maximise: the longest time, the fastest colour or the darkest possible result.

But pigmentation needs time to develop.

A longer session does not necessarily give a proportionally darker or more even result. Because the colour can continue to develop after exposure, it is good to let the skin show its full result before judging the next session length.

A gradual approach also makes it easier to see how your own skin responds.

Frequently asked questions about melanin and skin types

Tanning at Solportalen

At Solportalen the starting point is that different skin types have different individual circumstances.

Because different skin types respond differently, exposure schedules are available on site with recommended times for each skin type and sunbed. They serve as guidance when you choose a time that suits your individual circumstances.

If you are unsure about your skin type, the equipment or which session length might suit you, you are welcome to ask the staff before you begin. Contact us if you have questions.

If you would like to read on, we work through the most common misconceptions in Common Sunbed Myths – What Is Actually True?