Why Sun in is bad for your hair?

Shanna is a 23-year-old business professional and writer. She double-majored in economics and political science.

Is Sun In right for you? Read on to find out.

Is Sun In right for you? Read on to find out.

Tim Mossholder via Unsplash

Is Sun In Bad For Your Hair?

Sun In is one of the most popular hair-lightening/highlighting products on the market. My mom used this product as a teenager, and now, decades later, I use it to lighten my dark-blonde locks. Most people who use Sun In are looking for that sun-kissed, bright, and somewhat beachy look, but the truth is you get what you pay for.

Sun In is a cheap alternative to professional highlights and a quicker alternative to laying out in the sun for hours to let its light bleach your hair naturally. Because it is designed for hair that is already blonde or light, it may or may not work for everyone, and in some cases, it can cause irreversible damage.

Before attempting to lighten your own hair with Sun In, it's important to identify your hair type, understand the risks, and know how to use the product. In this article, we'll discuss . . .

  • The types of hair Sun In works well on
  • The risks associated with its use
  • The proper way to use it

What Hair Types Does Sun In Work Well On?

The label on the cheerful yellow bottle that Sun In comes in states that it works best on already-fair hair, or at the very least, light-brown hair. This is extremely important to note, and my friend's cautionary tale will hopefully convince you raven-haired folks to stay away from this product.

My Friend's Hair Nightmare

My friend has thick, dark brown hair that's really a naturally gorgeous color. For some reason, she desperately wanted highlights and had resorted to dumping every harsh thing she could think of into her hair—lemon juice, peroxide, and finally, Sun In.

She sprayed it on liberally and blew her hair dry. It looked vaguely lighter, slightly dryer and . . . well, normal. A few days later, after she spent hours in the sun, I got a panicked text that read something along the lines of "My hair is orange." It was true. Her dark hair had developed messy orange streaks that were permanent.

Long Story Short: Don't Use It on Dark Hair

Don't use Sun In if your hair is darker, as you'll be risking severe discoloration. It's also important not to use it if you've had a dye job or any highlighting done in the past six months. Basically, if you've undergone any sort of hair job involving chemicals, you should avoid Sun In.

My friend explained it to me like this: when you get something done to your hair at a salon, the chemicals that are used become a part of your hair shaft, and when they're mixed with other chemicals (like those in Sun In), harmful reactions can occur. In rare cases, these reactions can cause large chunks of your hair to simply break off (although the odds of this are fairly slim).

Additionally, my hairstylist told me that hair treated with chemical lightening products is difficult to dye properly, as the chemicals in the hair shaft can render the end result unpredictable. It makes it harder for your stylist to dye or highlight your hair because they don't know whether the colors will turn out like they are intended to.

Summary

Sun In works best on hair that is already light and has not been chemically treated in any way (at least in the past six months).

Know the Risks

It's true, Sun In damages your hair—a lot. There are some really harsh chemicals in that cheerful little bottle, so be careful. It's important to keep in mind, however, that bleaching your hair at home or getting it done professionally will cause even more damage than at-home lightening sprays. If you do choose to use Sun In, get ready to deep-condition and seriously love your hair.

How to Care for Your Hair After Using Sun In

I recommend a deep hair mask of coconut oil for a few minutes. Heat it up until it's liquid, and then apply it liberally to your hair. Let it sit and soak up some steam in the shower, and then shampoo and condition as necessary. Lather up twice, if needed, to remove the oils. I usually apply a nice leave-in oil to my wet hair before I blow dry it as well.

I also recommend avoiding using your straightener for a while if possible. If you blow your hair dry, use a low heat setting and brush gently and slowly. Growing hair is a long, time-consuming business, and damaged hair doesn't repair itself.

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How to Use Sun In Properly

Some people suggest following the bottle's instructions perfectly, and others suggest far more liberal methods. If you continue using it liberally over the course of a few weeks, your hair will indeed lighten. You can streak it through your hair or soak it each time, but always use it on a wet head. Using a hairdryer or sitting in the sun after applying can help the chemicals to lighten your hair.

When I first used Sun In, I had just gotten out of the shower. My hair was damp, and I sprayed it liberally throughout, combing it through to make sure I got every spot possible because I wanted an overall lightening effect. I then blew my hair dry and looked for results, but there were none.

Sun In generally doesn't deliver results after the first or second treatments. When I want to lighten my hair now, I use the product for three to five days in a row, after which I begin to see definite results. I then discontinue use until darker roots have started growing.

Should You Use Sun In?

You have naturally light hairSure

You have naturally dark hair

No

You have not treated your hair chemically in the last six months

Sure

You have treated your hair chemically in the last six months

No

You do not plan to dye or treat your hair in the next few months

Sure

You plan to dye or treat your hair in the near future

No

This is what Sun In highlights look like in  my dark blonde hair.

This is what Sun In highlights look like in my dark blonde hair.

Shanna11

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

Questions & Answers

Question: Can my hair go back to being dark after using Sun-In?

Answer: The part of your hair that has been sprayed can and might darken to a brassy orange color (it did with mine recently), but will not go back to its original color. As your hair grows in, it will be its original color, which may result in a different colored stripe in your hair.

Question: If my hair is damp, and I am planning on going to a water park, can I just leave my hair damp and let it dry with Sun-In naturally?

Answer: Yes, I believe so, but keep in mind that chlorine also acts as a bleaching/lightening agent and may have an additional or unexpected effect on the process. It shouldn’t cause any damage, but it might make the color come out lighter.

Question: I have natural highlights, will Sun-In ruin these, or just enhance them? I was also thinking about putting sun in on while I'm at softball practice, will sweat result in any strange effects?

Answer: Natural highlights will be further enhanced by the Sun-In! If you want to keep the highlighted look, you can spray the Sun-In heavily on your fingers and run that through your hair gently from the scalp down instead of spraying it all over your wet hair.

Sweat will not result in any strange effects, as long as it is dry by the time you start sweating.

Question: Is there any way I can get sun-in out of my hair?

Answer: Unfortunately, no. It is permanent.

Question: Is it ok to let your hair air dry after using Sun In?

Answer: Yes! But you won’t get the lightening effects unless you air dry in the sun! You need a heat source to activate the chemicals.

Question: I’ve used an equivalent to Sun-In a few mounts ago, and today I used blue shampoo as my hair was looking a bit orange, and now my hair is coming out, not in chunks but in strands. Can you help me?

Answer: If you last used the Sun In equivalent a few months ago, then it’s likely not due to that. It could be that the shampoo is irritating your scalp, or the hair loss could be due to hormonal changes or some illness. Hair coming out in strands is not indicative of a chemical reaction that would have been caused by the Sun In equivalent. If you feel that more strands are coming out than usual and this continues for more than a week or two or increases (I would recommend discontinuing usage of the blue shampoo to see if that has any effect), an appointment with a doctor would be the best next step.

Question: How long does sun in stay in your hair?

Answer: It is permanent, and will grow out as your hair grows out. I will note that in the past, it has grown out and the color dulled to a brassier stripe around my head as my hair gets longer.

Question: Do you rinse out the shampoo in your hair after you spray it, or is it a leave in lightener?

Answer: I shampoo as I normally do within the next day or two. It’s a leave in lightener. There is no residue, but a faint tropical smell.

Question: Does your hair have to be wet to use Sun-in?

Answer: I would recommend it, but no, it doesn’t.

Question: So I have only used Sun-In twice, and it’s already created a somewhat brassy tone. What can I do to prevent it from getting worse?

Answer: At this point, discontinue use. Time in the actual sun (without using more Sun-In) and growing out or dyeing your hair professionally (ensure that you inform the stylist that you have recently used Sun-In) are the only things that can fix it.

Question: Is there any way to remove Sun-In? I didn’t realize it was permanent until afterward, and I miss my natural hair color.

Answer: Unfortunately, there is no way to remove it unless you dye over it.

Question: Can I still dye my hair myself while "sun-in" is still in my hair? I’m not using any bleach on my hair so can I dye it or not?

Answer: It’s safer to dye hair after sun in use if it doesn’t contain bleach, yes. It can still damage hair, but if bleach isn’t involved, it’s less likely. Be sure to test a small section of hair first, to be safe, and use an intensive moisturizing leave-in conditioner after.

Question: My hair stylist said that if I was to dye my hair while using sun-in, my hair would fall out. is that true?

Answer: It likely won’t fall out, but it can be severely damaged. The chemicals in the sun in and professional hair dye can interact in unexpected ways, and burn or otherwise destroy hair to the point that the damaged parts might need to be cut off.

Question: I recently used Sun-in about a week ago and have an appointment in two days to possibly bleach my hair if my stylist says it’s ok. My hair seems healthy so my question is if you think it will be safe for me to bleach it?

Answer: Inform your stylist and if she says it’s okay, it will likely be fine. My stylist said that as long as clients let her know about using it previously, she can take steps to mitigate damage, or mitigate the hair dye coming out a weird color.

Question: I have naturally curly hair. If I use Sun In, will it ruin my curl pattern?

Answer: Nope! It is safe for curls.

Question: Will Sun-in work for a person with chocolate brown hair?

Answer: Probably not. It really only works for dirty blonde and lighter shades of hair. You run the risk of getting brassy/dark orange streaks that can ruin your hair. Professional salon work for darker shades is better.

Question: Is Sun-In permanent?

Answer: Yes.

Question: How long does it talk to get results of Sun-In?

Answer: I see results after one application but usually, I apply every two days (I wash my hair every two days) after showering for a total of three applications, and then I have the two to three shades lighter advertised on the bottle.

Question: How soon can I get highlights after using sun-in?

Answer: I usually wait three months! But the most important thing is just to let your stylist know you used sun-in. She can better prepare for any funky discoloration that might happen.

Question: Does Sun-in Damages flatten your hair?

Answer: No, it does not.

Question: Can I use Sun-In on dark red dyed hair? The dye was from L’Oreal, and it wasn’t ammonia free.

Answer: I wouldn’t risk it. Red hair and sun in often make a brassy orange color that doesn’t look great.

Question: Will natural blonde hair get black roots when using sun-in?

Answer: Nope! It will get lighter.

Question: How long does Sun-In stay in for?

Answer: It is permanent.

emma on July 15, 2020:

Can i apply some oil or conditioner before applying the sun in to reduce the amount of damage done? will it still lighten my hair?

My2Cents on May 21, 2020:

Curly, medium-dark brown chestnut hair here. Have done many coconut oil hair masks before for hydration, and almost never use heat-styling products. Dyed hair with body-art quality henna, then used Sun-In some days later. Very pleased with Sun-In; no issues whatsoever, and color turned to the beautiful auburn I wanted.

Victoria on February 15, 2020:

I just want to put this comment out there to help anyone with dark hair that’s planning on using Sun-in. I have naturally ombré hair and instead of getting my hair professionally highlighted like i should have. I used Sun-in, BIG mistake. It definitely lightened my hair a lot, surprisingly. but after using it a year and a half later i decided i’d go blonde professional this time around. Well, long story short the Sun-in had a bad reaction with the beach and a chuck of my hair was completely damaged it. It looked like noodles, the hairdresser literally broke my hair in half with her fingers !! it was insane. Extremely devastating, i do not recommend using it.

7064900990 on July 17, 2019:

I have used it for years & love it. All of a sudden Walmart in Clayton, Ga. stopped selling it. Where can I get it?

Mattie on April 15, 2019:

This hair product made my dark hair lighter just not in the way I would have Iikes it . It turned RED

Roxyriggs on October 18, 2018:

I had a hair disaster in junior high using Sun In. My best friend had lighter hair and so hers turned a lovely blonde color. My hair is more Brown than blonde and turned a horrifying orange shade! I've avoided Sun In like the plague since then. I didn't understand about how hair dyes and bleach worked back then. You see, you have to lift the color beyond the orange up to blonde. So anyone who is seeing orange needs to continue using the product until you lift the color from orange to blonde. I wish I'd known that in junior high! It was very traumatic. I cried and I prayed and I scrubbed and scrubbed my hair hoping I would scrub the orange out haha. Had I known what I know now, I would have just kept at it until I lifted the color from orange to blonde. It would have saved me a lot of drama and embarrassment. I recently was tired of the damage that bleaching and highlighting my hair was doing and so I gave Sun-In another chance. I used the pink bottle; the Tropical Breeze scented Sun in I was amazed! I freaking love it! It's much less expensive then anything else I've ever done to get highlights in my hair or to make it blonder, it's less damaging and it works!!! I'm amazed and thrilled, especially as I lost most of my length with my last hair color disaster. I had stopped going to the salon due to the high cost and was very successful and putting highlights in my hair myself until the last time that is. I had mohawk-short hair on the top and it was odd shades of orange, bleached out fried yellow hair, pastel pinks and purples ... the purple was from the purple shampoo that I had used trying to tone the orange tones out. It was a mess. Lots of coconut oil and cod liver oil treatments and just leaving it alone has helped to get back in shape. It's finally growing out but I wanted highlights! Sun-in is my solution from here on out. So remember, if your hair starts turning orange, you need to lift it beyond the orange. Don't be scared; just keep going with it. What have you got to lose except orange hair right?

Z on June 12, 2018:

I have black hair and it's short (I'm a guy) so maybe the length made the difference but after using it about 5 or 6 times my hair was near light brown. It worked perfectly for me. Sadly, the effects went away after a few weeks because my hair grows really fast :C

Michael McGlothin on April 19, 2018:

I've used Sun In for several years and it hasn't really hurt my hair, but I don't always get enough sun exposure mostly early fall until mid spring so the blonding process takes a little longer. I even use it on my Duck Dynasty length beard but it's a little red until it goes totally blonde. Beards take longer than scalp hair but they will blonde out. Oh, I forgot to add I have med-dark brown hair naturally.

Mandy on April 02, 2018:

I have dirty blonde so I used sun-in rarely like a few times over the summer, and when I saw my relatives at the end of summer they all realized a tremendous difference and also realized he almost orange tinge. It has now been several months and my roots have grown in and ITV does no look the best. I don’t think it worked that well for me but for my friend it did. Although she constantly puts its in her hair. I think I would recommend it to people who r willing to keep with up the commitment of putting it in. Also once u put it in once and see changes then wait til roots grow our and apply it just on the color change, so don’t relayer it on old already dyed strains. Then the orange look begins to occur.

Madi on March 26, 2018:

I have dirty blonde hair and after using sun in 3 times my hair was orange... I DONT RECOMMEND

Mallory on November 18, 2017:

I have dark blonde un dyed hair and used sun in over the summer. Naturally as my hair lightened, it had an orangey/bronze tint to it-which seems to be in all the horror stories about this product. The fix was simply using purple shampoo & conditioner (I use L'Oreal Ever Pure blonde shampoo). After maybe 3 uses, my hair was as blonde as originally intended!! just food for thought! And if you're worried about damage, use overnight hair masks after having used the sun in. I havent had a problem yet.

Melanie on July 20, 2017:

How can I get it of my hair? My mom is soo mad because I look like a clown with this hair. PLEASE HELP

Sophia on June 27, 2017:

I have natrually light(ish) brown hair.

I went blonde for a while NOW I have a brown toner over my bleached blonde hair.

I want to be blonde again by using Sun in.

Will my toner cross a bad road with Sun In chemicals?

HELP

Ruth S on June 12, 2017:

I have let my hair go grey and was wondering what sun in would do to it???

Christine Karow on May 25, 2017:

Don't ever perm over this.

Lauren on May 23, 2017:

I have regularly used Sun In since 2008. My hair got darker blonde as I reached the end of high school in 2007 and when I discovered Sun In in 2008 it was a dream come true! I would only use Sun In once or twice a year since 2008 until I moved from California to the UK in 2012 when my hair started to darken again. So now I use it a lot during winter and a bit before summer starts so my hair can look nice and bright blonde year round. I don't get any bad reactions. Not much notacibly split ends. No averse color changes.

emmy on May 22, 2017:

I have medium blonde hair and I use about 2-3 pumps every few weeks after a shower while it's still wet. Without it, no one notices my hair. It's cold and uninspiring. Just a little sun-in gives me subtle highlights.

If I spend hours per day out in direct sunlight, I get highlights naturally but I'd be working on getting skin cancer too.

To be honest, I've never read the directions. I use it the same way my aunt who has the same natural colour as me taught me to use it. My mother has dark, dark brown hair and I was told it doesn't work on her hair. I thought the only people that use it have fair hair.

Clare on April 19, 2017:

Sin in plus hair dyr plus straightners rotted my hair I had to shave it off to a crew cut and start again yuk my hairs fine now I still dye it but will never use sun in crap or straightners ever again

Alejandra on May 25, 2016:

You do get a very bad chemical reaction if you plan to make a trip to the salon! Im a hair dresser and i just happen to do a set of hilites without imagining that my client had used sun-in , her hair felt off !!i had never seen anything like this before

Z on May 12, 2016:

I used Sun In for a few weeks in the summer and it looked beautiful with my black hair. All was well until a year later when I got my hair done at the salon. Believe this review and its warning about bad chemical reactions. My hair literally began to fall out. Luckily I have long hair so we were able to cut the damaged part off. Both my hair stylist and I were so confused why this was happening until I remembered that I had used Sun In over a year before only a had few of times. So just keep in mind that while it does work, don't use it if you ever plan to get your hair done in the future.

Alissa on May 05, 2016:

I have used Sun-In before. For reference, I am Asian with JET BLACK hair. It worked just fine on me. I sprayed it liberally on my wet hair and combed it out for even distribution. I then waited outside in my backyard and allowed my hair to dry. I repeated this step every few days for 2 weeks. My hair turned into a beautiful auburn brown shade with blonde streaks all throughout my hair. I can personally vouch that this product worked on my pin straight Asian jet black hair. And with absolutely no damage either. My hair is as healthy as it comes. But to each their own, everyone has different experiences and what worked on me may have reverse effects on someone else.

Mel on January 06, 2016:

I have used it since I was 16 on light brown hair to give me a golden blonde look. Still use it 20 years later and never needed hairdressers for lightening.

bex on January 26, 2015:

I was born a blond but over time my hair started to darken. I began spraying sun in in my hair before marching band practices (9 hours in the sun) this was when the brown started to appear so I never had a full head of brown I basically lightened the growing in roots. For years I never noticed anything bad but eventually when my hair got a lot longer I started to notice some damage. But I also don't trim my hair so that was a part of the problem. Those don't mix well. I eventually decided to grow out my hair without the lightener because I was curious what my natural was. Once that started happening I noticed the new hair was thicker, healthier, and shinier. I currently look like I ombreyed my hair because of the growing out process. I at this point in my life have decided to go natural. Now healthier hair is more important than blond. But the damage isn't terrible if you want lighter hair and honestly I think it is the best method if you don't overdo it. But no matter what lightening your hair causes damage. The thing people don't realize and I made this mistake before is the lightening isn't instant. You may blow dry your hair and see now difference. It will be lighter by the next day to not add more instantly. It is a patient process to do it right. Do it over a period of at least a week.

paula on November 02, 2013:

I've used Sun-in since I was 18 I'm now 36 and still use it I have light. blonde hair but as I have got older I need it more but I will have to try proper dyes in the next couple of years as it won't work with gray hair give it 8/10

Jessie on June 23, 2013:

Sun in is amazing. I wanted a lighter shade then I had. I have lightish brown hair. First of all I wanted to say something....'sun in has no damage to your hair! When I used sun in it was so simple, just spray and wait in the sun! It works wonderfully you won't regret!!

Catherine Dean from Milledgeville, Georgia on September 17, 2012:

I cannot believe they still make Sun-In. At least they have changed the bottle in the last 25 years. I hope it smells better these days. This took me back...a long way back.

Cristale Adams from USA on June 30, 2012:

I have too much dark hair color on my long locks for it to work. It looks great in your hair!

emilybee on June 30, 2012:

I've never tried sun-in. My hair naturally lightens up in the summertime and often I spritz a bit of lemon juice in before hanging outside. By end of summer my hair is usually much more blond. Thanks for the info on Sun-In for I previously did not know much about this product.

Is Sun

If your hair has prolonged exposure to the sun, UVA and UVB rays can damage the outside cover of the hair strand, called the cuticle, says dermatologist Wilma Bergfeld, MD. “Sun damage can come in the forms of discoloration, dry and brittle strands, broken or split ends, thinning and frizziness,” says Dr. Bergfeld.

How often should you put Sun

As I mentioned, Sun-In works via heat application, not actual sunlight, so this is why this method works too. You can repeat this process every day on dry hair until you achieve the desired level of lightness. If you wanted to you could probably do two rounds in a day.

Is hair lightener bad for your hair?

You have probably heard that bleaching and highlighting your hair can damage it. This is true, bleaching agents are hard on your strands. They can make your hair dry, brittle, frizzy-looking and prone to breakage.

How do you use Sun

Answer: It's safer to dye hair after sun in use if it doesn't contain bleach, yes. It can still damage hair, but if bleach isn't involved, it's less likely. Be sure to test a small section of hair first, to be safe, and use an intensive moisturizing leave-in conditioner after.