All About Sun Bleach Hair – The Science

Several studies have shown that sun exposure can bleach out the melanin from the hair, making it lighter. Sun’s ultraviolet rays oxidize the hair making it strip its color pigments (melanin).

But can it replace your salon visits for bleach?

And more importantly: Should you consider bleaching your hair with the sun?

In the sections below we will break down all the scientific studies on sun bleach hair along with pros and cons.

How does Sun Bleach your Hair?

As per the study published in 2011, sunlight causes photo-degradation on human hair. Melanin oxidation by free radicals causes bleaching. Keratin damage is also caused by this.

Your skin and hair contain melanin, a color pigment that is responsible for your unique hair color. In contrast to the skin, hair consists of just dead cells. To put it another way, any change in hair color is permanent until the hair grows back.

The melanin in your hair is stripped away by the sun, resulting in lighter hair. Your hair’s amino acids are oxidized by both UVA and UVB radiation. The pigment in our hair shafts begins to fade due to exposure to UV light. Photo-yellowing, or yellowing of the hair, may result from this. This has already been scientifically proven in a study conducted in 2007.

How long does it take for sun to bleach hair?

The sun’s UV rays start bleaching your hair within 15 mins of exposure, depending on your hair’s condition. By hair type, thick hair would take as much as 45 mins to get sun-bleached whereas for fine hair it could take as little as 15 mins. By hair tone, dark hair might take as long as 30 mins but for blondes, the bleach effects may start in just 10 mins.

But it takes multiple hourly sessions of 7 days or more before you start noticing any significant difference. You can make this process faster by adding lemon juice or some sea-salt spray into the mix. But keep your expectations realistic as sun bleaching won’t give you the same result as a salon bleach.

How to Sun Bleach your Hair Faster?

The sun’s rays will ultimately lighten your hair if you leave it out in the sun for long periods of time. For the best results, though, you’ll likely need to expose yourself to direct sunlight for several days. However, there are few natural ways to make this process faster. 

  • Lemon Juice: Using lemon juice to lighten your hair is a safe, natural, and affordable option. It may help you maintain a healthy pH level in your scalp. It may help alleviate skin irritations such itching, dryness, and flaking if used in moderation. Lemon juice, although being gentler than certain hair bleach, is nonetheless acidic. The juice might dry up your hair and scalp, so be careful. In addition to causing hair breakage and dry, frizzy locks, this may also cause irritation to the scalp.
  • Apple Cider Vinegar: You may use apple cider vinegar to lighten and bleach your hair with reddish highlights. Soft and lustrous hair may be achieved using apple cider vinegar, which covers the hair cuticle. It can also strengthen the outer layer of the hair by shutting the cuticles and the hair shaft, therefore protecting your hair from damage.

Pros & Cons of Sun Bleach Hair

  • Expenses & Maintenance
  • Bleaching Result
  • Bleaching Time


Pros & Cons of Sun Bleach Hair


  • No need to spend money on expensive serums or creams
  • No need to visit a professional hairstylist
  • Bleach your hair naturally using sun’s ray
  • Sun bleach works on all shades of hairs
  • ‘Sun-kissed’ hair creates a great appearance


  • Sun’s UVB rays can breaks down and damage hair shaft’s protein
  • UVA rays bleach your hair but can also weaken the hair shaft
  • Too much sun exposure can rupture the hair’s outer layer
  • Can cause split ends
  • Sun bleach makes the hair brittle & dry

Is sun bleaching bad for your hair?

Sun bleaching may seem to be a natural procedure, but it is not a safe method of lightening hair. If your hair is exposed to the sun for an extended period of time, UVA and UVB radiation may cause damage to the cuticle of the hair strand. If your hair is exposed to sunlight, it is at risk for damage such as split or broken ends and dry strands. If you have thin or light-colored hair, it is more prone to sun damage.

Your hair’s protein structure decreases and moisture is sucked away by the sun, resulting in less flexibility and increased breakage.

You may also notice that your hair is drier than normal, making it more difficult to style.

To make matters worse, if your hair has been colored, it’s significantly more prone to both internal and external harm. It’s also worth noting that UV rays act like bleach on hair, causing it to fade or become brassy more quickly.

Your hair’s protective coating of lipids may be damaged by prolonged exposure to the sun.

The interior structure of your hair may also be damaged by the sun, leaving it brittle and prone to split ends and breakage.


The melanin in hair may be bleached off by the sun’s radiation over time, making hair seem lighter.

It’s not always a negative thing if you lighten your hair naturally, but you should keep in mind that any bleaching you do results in chemical alterations, which might have unintended side effects. The sun’s rays are only as harmful to us as the amount of sun radiation exposure and how much our genetics allow them to be.

If you let the sun bleach your hair, you can mistakenly believe you’re obtaining a wonderful, sun-kissed appearance. However, the yellowish (or “golden”) hue may be the consequence of sun exposure. Amino acids in your hair are oxidized by UV radiation, which is why sun protection is so important. Hair yellowing, often known as “photo-yellowing,” is a common side effect of this treatment.

Those with fine or light hair are more susceptible to UV damage, while those with thicker hair and darker hair color are more protected from the sun. All hair kinds and hues, however, may be damaged.

If you want to lighten your hair but don’t want to expose yourself to the sun, there are alternative options!

Check the article on 10 Scientific Ways to Make Bleached Hair Soft and Silky


Does Sun in make your hair orange?

Yes, sun in can make your hair orange due to added effects of lotion. But the chances of that occurring are quite slim and even if it happens, it would be just an orangish hue.

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