K18 TripleBright Purple Shampoo Review

If you're blonde, you've probably tried at least one purple shampoo in an attempt to keep your hair color bright, fresh, and free of brassiness. Truth be told, it’s hard to find a good one. They either overtone and leave your hands (or scalp) purple tinted, barely make a difference, or dry out your hair.

At this point, I’ve tried them all, or at least I thought I did, until someone at Sephora pointed out the K18 TripleBright Oxidation Defense Purple Shampoo Foam. As a brand, K18 is all about unique, science-backed formulas, so I was very curious to learn more.

Unlike a traditional purple shampoo, TripleBright has a lightweight foam texture, which I've never personally seen before. It’s also designed to do more than simply deposit violet pigment. K18 says it helps remove metals and minerals that contribute to brassiness while also neutralizing existing yellow and orange tones, so you’re getting brighter, fresher hair overall.

Below, I'm sharing my honest K18 TripleBright review, including my before and after results, how well it works, pros, cons, and whether it’s worth the $39 price tag.

k18 triplebright purple shampoo foam review: is this foam purple shampoo worth it?

K18 TripleBright Purple Shampoo Foam is one of the most unique shampoos I've ever tried. With a foam texture, it’s designed to approach (and fight) brassiness in three different ways:

1. Targets metals and minerals associated with oxidation

2. Neutralizes existing brass

3. Help reduce future brass build-up

It’s also a standalone product; there is no “matching” conditioner so it’s formulated to be strong enough on its own. K18 recommends applying 2–3 pumps to wet hair, leaving it on for 1–3 minutes, and using it up to once a week.

Overall, I really love this shampoo and while $39 is expensive, it’s worth it if you want to tone your hair in one step with one product (versus buying a shampoo and conditioner). It lathers well, has a fresh citrusy scent, and is easy to wash out. The main downside is that it stained my hands (especially around my cuticles), but did not stain my hair or scalp and the purple tint on my hands went away after washing a few times post-shower.

The results are pretty dramatic, especially since it’s a singular step. My blonde was brighter and all brassiness was gone, but my hair didn’t look overly toned. More importantly, my hair did not feel dry or straw-like, which is common with many toning shampoos. I’ve used this shampoo by itself (no conditioner or leave-in afterwards), and truly, it is the least-drying strong purple toning product I’ve ever used.

k18 triplebright purple shampoo before and after

how to use k18 triplebright purple shampoo foam

K18 TripleBright Purple Shampoo Foam is not just unique in formula; the instructions for using are a little different than you may expect, too:

• Apply foam shampoo to wet hair, distributing evenly and lathering from roots to ends.

• Let sit for one to three minutes, then rinse.

I personally like to use 2 pumps on my fine, long hair. I recommend starting with one pump and then adding more; the foam can get messy in the shower and I hate wasting product, so I’ve found using one pump at a time helps me get a good lather going without spilling any product.

I also recommend leaving it in for the full 3 minutes. One minute barely made a difference in my hair, but if you try to go for 4+ minutes, your hair may end up with a purple tint (remember, purple shampoo doesn’t brighten color - you need bleach for that).

Lastly, the directions say to lather your ends, which is atypical for a purple shampoo. Don’t be afraid of this, though; it really does help tone your hair without drying your hair out.

I’ve tried the shampoo by itself as well as with a few different conditioners. I recommend using your normal conditioner (not a toning one) or hair mask. The K18 TripleBright formula is not drying, so your hair may not need a heavy-duty mask afterwards, but it tones well enough on its own that you do not need to use a toning conditioner afterwards.

did the foam actually lather?

Obviously the foam texture is what gets your attention first and foremost as the “standout feature.” Most purple shampoos are thick, creamy, and deeply pigmented. TripleBright comes out as a foam, which K18 says is intended to make application and distribution easier. The foam itself is a true violet color, meaning it has both purple and blue tones to fight against yellow and orange brassiness.

As far as its ability to lather, it does a great job and feels like a lightweight shampoo as you work it into your hair. I like that it was also easier to rinse out, whereas some of the creamier toning shampoos seem to stick to your scalp.

k18 triplebright pros and cons

pros

• Unique foam formula

• Easy to work into your hair

• Not drying at all!

• Works well on its own; no need to also purchase a toning conditioner or mask

• Also fights hard water build-up

• Light, fresh scent

• Doesn’t cause tangles

• Effectively removes all brassiness in 3 minutes

cons

• Expensive

• Need to leave it on for the full 3 minutes to get results

• The foam has a little bit of a learning curve (start with one pump!)

• Being a foam, you’ll go through this quicker than a traditional shampoo

• Temporarily stains hands

how does it compare to traditional purple shampoo?

There are a few key differences to keep in mind. K18 TripleBright Purple Shampoo Foam:

• Has a foam texture

• Focuses on oxidation and brass, not just color-depositing

• Needs to be left on for 1-3 minutes

• Is more expensive ($39)

Traditional shampoo:

• Is typically liquid or cream

• Primarily deposits violet pigment

• May or may not need to be left on

• Has a wider price range

One last thing to note is that K18 says it has formulated its purple shampoo to not overtone your hair. I found that to be true, but I never left it on for longer than the 3 minutes as directed. However, it stained my hands whether I left it on for 1 or 3 minutes, so I could see the shampoo over-toning your hair if you leave it on for like 5-10+ minutes.

is k18 triplebright worth the price?

K18 TripleBright Purple Shampoo Foam is worth it, in my opinion. I love that you get a full, proper tone in just one step, and this is one of the few toning products that doesn’t make your hair feel dry at all! It’s pricey, but you don’t need to buy a toning conditioner, so it isn’t the most expensive solution when you are looking at the big picture.

That said, I don’t think this foam will last as long as a traditional shampoo and you will need to repurchase it more often compared to a regular shampoo. I don’t particularly mind this because the results are so good, but if you have long, thick hair, it’s something to keep in mind.

buy it if you:

• Have blonde or highlighted hair

• Want an effective purple shampoo that isn’t overly pigmented

• Are worried about over-toning your hair

• Live somewhere with hard water or mineral build-up

• Want a lightweight formula

• Want to tone your hair in just one step

• Have dry hair that is prone to breakage

skip it if you:

• Want the cheapest possible purple shampoo

• Prefer traditional creamy shampoo formulas

• Are on a budget

• Do not want a product that may stain your hands

frequently asked questions

is k18 triplebright a purple shampoo?

Yes.

how long should you leave k18 triplebright in your hair?

1-3 minutes. I recommend 3 minutes. One minute didn’t make much of a difference on my hair, but longer than 3 and you do run the risk of over-toning your hair.

how often can you use k18 triplebright?

Once a week at most; if you only have highlights or a more neutral tone to your hair (versus cool, icy blonde), every other week will work, too.

will k18 triplebright turn hair purple?

No, but don’t leave it on longer than 3 minutes recommended or else it might. My hands stain every time I use this shampoo, so it is one of the stronger formulas out there.

does k18 triplebright work on fine hair?

Yes; I have fine hair and love how lightweight the foam is.

is k18 triplebright drying?

Not in my experience.

do you need a conditioner after k18 triplebright?

Not necessarily; I have used the shampoo without conditioner afterwards and my hair didn’t feel dry or fragile. That said, I would highly recommend using one! The shampoo formula is strong enough that you can use a normal conditioner (no need to buy a toning conditioner). I like this one; it’s lightweight yet hydrating.

is k18 triplebright good for hard water?

Part of what makes K18 TripleBright unique is that the formula also works to remove brass-inducing metals and minerals associated with hard water. In my experience, my hair did have that fresh feeling I get with typical detox/ clarifying shampoos without the dryness, so if you want to tone and fight mineral build-up, it’s a great option.

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