I have been dying my hair with sun in since the 9th grade. I have naturally dirty blonde hair. It definitely grows out and makes my hair a million colors, so its not the classiest thing in the world but it goes from this natural sunkissed summer hair to a darker blonde in the winter. I've been using it so long, though, that the ends of my hair are now bleach blonde. I'd recommend spraying your roots instead of your tips since the product will inevitably drip to your ends. Really great and I'll continue purchasing this. I have actually seen my hair become nicer with sun-in and when I don't use it in the winter my hair is definitely yuckier.

I'm sure I'll start getting it professionally highlighted when I'm older and need to be a bit classier.

I've been using this product in my hair for years. Just how others said, it should only be used on natural blonde or light brown hair, otherwise it'll turn very brassy. I have naturally dirty blonde hair and I use this product to keep it a medium golden blonde. I use a blow dryer to activate it, and it works pretty well. I would suggest doing it a few days in a row to get the desired color. Also, once you get the shade desired I would not put the product on the ends of the hair, only the roots to do touch ups (if you use it on your whole head like I do). The only thing that bugs me with the packaging is sometimes the little cover for the nozzle falls off and the spray gets jammed. Besides that this product is great and a good price.

Honestly some comments are just useless. People keep complaining about how it "damaged" their hair while using it with hair straightener let alone blow dryer. Well flash news for all of you girls hair straighteners can go up to 170C so of course with peroxide on your head your hair will end up brassy and fizzy or whatever you call it. Don't trash the brand if you can't abide the product's nature of use.

Okay, if your are blonde, go for it. It will work well for you. Everyone else, run in the other direction. Trust me.
I have light/medium brown hair, and i used it for a few weeks a two summers ago. It turned my hair a horrible brassy orangish color. And i didn't really notice because it was gradual. It seems to be working beautifully at first. Key words 'at first'. But man, was it bad. So i immediately stopped using it.
Then, at the end of the summer i went to have my hair cut, and colored, to cover up the orange. The colorist immediately recognized that i had used sun-in. And here's what she told me- Sun-in is a metallic-based hair color. Which means it's absorbed into your hair. Permanently. It doesn't wash out. And Sun-in is heat activated, which means every time you straighten, or curl, or blow dry, or go out into the sun, the sun-in continues to damage your hair. Forever. Until you cut it out.
So, blondes, it wont turn your hair orange. it will give your your desired color, but it will damage your hair. proceed at your own risk.
EVERYONE ELSE- Never even pick up the bottle. i promise you that you don't want to. It took over a year and a half to get the orange completely out, and that included cutting my long hair up to my shoulders.
In conclusion, just do something else. Lemon Juice works well.

I used it last summer for the first and the last time.
Almost every day I went to beach and got highlights from the sun.
My hair is medium brown and the highlights I got came out rusty. It does the job it supposed to do but the color was dull and mat.
I am still trying to get rid of the highlights by cutting them off little by little.
I still think it will look good on blond hair, but not on mine, plus I am too lazy to treat them to look vivid.

I must start by saying I really love this product and it did everything I expected and more! This product however, is not a one-size-fits all product. If you have dark brown, black or red hair I would avoid it entirely, because it might turn those hair colors terribly brassy and orange. I have medium brown hair that turns to a golden-light brown in the summer, i wanted to enhance that color in the summer time as well as keep the same hue all year round, so I bought sun-in. I spent 2 years deliberating whether or not to purchase this because I was afraid of a possible brassy hair color, but let me tell you im so glad I bought it! It made my hair a gorgeous light golden brown that i was striving for and it looks so natural! The spray works best under sun-light but it also works well with a blow dryer. I get my desired results in 2-3 uses and it comes out non-streaky looking and lasts for around 2 monthes before it starts fading away. I get so many compliments on it too! If you have blonde to medium brown hair, and are looking to lighten your hair try it out- you wont regret it! If you have darker hair try the spray out first by applying it too a small section of hair that is not immediatly visible, that way you can play around with it before applying it all over!

I used this product on my hair this summer and it worked pretty well. I have very curly very thick hair and was in the sun about 6 hrs a day for 1 week in the summer and the sun-in cased my hair to have a reddish tint with light brown highlights. It was very subtle and I completely loved it. I also didn't follow the directions all the way. It says on the packaging that your supposed to put in in with wet hair, but I never did. I loved how my hair came out and I like the sun-in better because I don't want to dye my hair. If my hair was thinner it probably would have made all of my hair one color.
A Tip for people who want there hair to have streaks threw there hair, kind of like highlights (trust me it looks great in lighting and the sun) braid or twist your hair, then dampen you hair a little bit. Lastly spray the sun-in into the braids or twist and continue on with your day outside. Or you could blow dry it if you wanted, its supposed to be faster. Every day for 4 days do the same thing. I hope this was helpful...

I am about to purchase my second bottle of this product. I have been using the product for 6 months now. It turned my natural light brown hair into a golden blonde. Smells lovely and doesn't damage hair any more than a regular professional highlighter. Awful packaging which put me off the purchase for a while, but certainly worth the price.

Excellent! Don't listen to people who say it turns your hair red! It brings out your natural highlights and says right on the bottle that darker hair will have red highlights as a warning! Amazing and didn't ruin my hair AT ALL. lovelovelove sun in!

I used this years ago as a teen and it was not worth it then either. Try Marc Anthony's Easy Lites instead, found at CVS or RiteAid for $9. With sun it, its a whole complicated process compared to Easylites where you simply spray the dry hair shaft and flat iron those strands 5-7 times. The lightening effect is immediate.You can do it on darkest to lightest hair, even color treated. Sun in sucks. Skip it