Does Sunlight Bleach Your Hair?

Women with sunglasses and wavy hair smiling in front of the sun.

Hot summer days call for cool shades and protective sunscreen. Don’t forget to protect your hair too! As the summer comes, do you ever notice your hair drying out or maybe even getting lighter in color? Well, it’s that time of the year to really watch out for the sun — more specifically, UV radiation.

What is UV radiation?

Ultraviolet (UV) radiation is a form of electromagnetic radiation which comes from both the sun and artificial sources like tanning beds and black-light lamps. Overexposure to UV radiation is damaging to the skin and hair if you don’t take the appropriate measures to protect yourself.

There are three main types of UV rays: UVA, UVB, and UVC. These different types of UV rays are based on their wavelength. The UVA rays have the longest wavelengths, followed by the UVB rays, and then UVC rays which have the shortest wavelengths.

There are three main types of UV rays: UVA, UVB, and UVC.

UVA and some UVB rays reach the Earth’s surface, while all UVC and some UVB rays are absorbed by the ozone layer. As we spend time outdoors, we mostly come in contact with UVA and a small amount of UVB rays — even when it’s cloudy out!

How Do UV Rays Affect Your Hair?

Research shows that excessive sun exposure can impact your hair in a couple of ways, which includes UV radiation causing your hair to change color. Basically, sitting out in the sun for long periods of time can bleach your hair.

The sunlight bleaches out the melanin (the pigment that gives skin and hair color) and removes the color in your hair. This color change is due to high exposure to UVA radiation, and the result depends on your natural hair color and undertones. Everyone’s hair color will lighten if they spend enough time in the sun, but the color change is more noticeable in lighter hair.

You can think of this process as a photo that’s been left in the sun and the colors fade over time. Although some might think that the change in hair color looks nice, there’s more you should know before spending hours trying to bleach your hair outside in the sun this summer.

Damage From UV Radiation

While UV radiation can lighten your hair color, it can also destroy hair proteins and cause hair damage, such as dryness, reduced strength, stiffness and brittleness. In this case, the type of UV radiation responsible for hair protein loss is UVB radiation. When the proteins are damaged, it’s easier for the sun to penetrate your hair and make your strands more fragile.

Contrasting UV ray damage on hair versus skin is important. While UV rays are a main cause of skin cancer, they cannot create that same degree of damage on hair. It is common understanding that hair does not contain living cells.

With this in mind, your actual hair strands are unable to develop malignant, cancerous cells. The damage that occurs by UV ray exposure on hair is usually replaced by new, healthy growth, even if it takes a longer period of time during the hair growth cycle.

Protect Your Hair

Summer is one of the best times of the year, but make sure to take the proper steps to protect your hair from the sun. Try to stay in the shade when you go out, especially during midday hours. Wearing a headscarf or a wide brimmed hat is not only cute, but it’s great for blocking the sun. There are also SPF products specially made for hair and scalp protection.

Wondering what else you can do to maintain your hair during the summer? Read our full blog here for more healthy summer hair tips