Suveen Sahib on repairing bleach damage in four minutes

Bleached hair that still feels like hair starts with less in the shower, not more. Suveen Sahib and Britta Cox built K18 around one peptide and a four minute wait, then took it to stylists first. Here is how to use it at the sink, in the chair and on wash day.

In 2020 in San Francisco, Suveen Sahib and Britta Cox decided to stop covering damage and start working with the biology inside the strand.

Cox had spent decades thinking about wet hair. She started AQUIS in 1990 after working with wicking fibers from the ski industry, patented a turban shape with a button loop, and heard from customers that a towel could leave hair less frizzy and smoother. Sahib listened, then started reading chemistry, biophysics and biochemistry to understand what water and bleach actually do once the cuticle lifts.

What they built next is now familiar in salons and on bathroom shelves. K18 launched in professional channels in the first quarter of 2021 in the United States, then globally after testing in the United States and Australia. The hero is a leave in mask powered by a patented peptide, applied after shampoo, left for four minutes, and never rinsed out. The promise is plain: reverse the look and feel of chemical damage from the inside out, with less product, less time and less frustration.

What others miss is the discipline underneath. This is a brand that chose stylists before feeds, that scanned long stretches of keratin biology with researchers at the University of Minho in Portugal, and that asks you to shampoo, squeeze out water, use a small amount, wait, then style. Body of Work sat down with Sahib, in the voice of both founders, to show that work step by step.

You come from AQUIS towels to a peptide mask. In 1990 Britta starts AQUIS after working with wicking fibers and patents a turban, and by 2020 you both found K18 in San Francisco. What did the towel years teach you about wet hair that made a repair mask feel necessary?

I became hungry to learn everything there was to know about hair in its natural state. That is where it started. Britta had spent years watching what happened at the sink and after the shower. People told us the AQUIS towel saved their hair, made it less frizzy and smoother, and that stayed with us. Wet hair swells, it tangles, it breaks if you rush it. You can feel that with your hands before you read it in a book.

I became obsessed after this conversation, reading chemistry books, then biophysics and biochemistry. I wanted to understand chemically damaged hair, not just damp hair. We talked with skincare delivery scientists, then with Professor Artur Cavaco Paulo and his team at the University of Minho. The science came first, then we built the brand from there. I always tell my team nature is the best designer. If you respect how hair is built, you stop piling on coating after coating and you start asking what the fiber is missing inside.

You describe a decade of scanning amino acid sequences covering the genome that makes up human keratin with researchers in Portugal. What did that search actually involve, and how did one sequence become the K18Peptide in a four minute mask?

You cannot solve problems by being inside the problem. We had to step back and look at biology. The team modelled human keratin with mathematical and molecular tools, then scanned amino acid sequences covering the genome that makes up human keratin. That work took the better part of a decade with Professor Cavaco Paulo and his team. We were looking for a sequence that could get inside a damaged fiber and help support its inner structure, not sit on top.

One sequence kept showing up when applied to damaged hair. That became our patented K18Peptide. It is made with biotech methods, and our formulas are vegan and cruelty free. The mask itself is simple on purpose. Shampoo, do not condition first, squeeze out excess water, apply a small amount from ends up, wait four minutes, then style. Leave it in. That four minutes matters because the peptide needs time in the fiber without conditioner blocking the way. Stylists were blown away by the results when they first tried it in the chair, and that told us the lab work translated to real heads.

You launched in professional channels in the first quarter of 2021 after testing in Australia and the United States. Why put a new mask in stylists hands before selling it straight to bathroom shelves?

We want to be part of the culture where hair actually gets changed, and that is the salon. Bleach, color, perms and relaxing all break inner polypeptide chains and disturb the bonds that give hair its strength. A stylist sees that damage up close, section by section. If the product did not hold up during a bleach service or a color correction, it did not deserve a shelf.

So we tested in Australia and the United States, then launched through professionals in the first quarter of 2021 in the United States and then globally. The mask fit the chair routine. Shampoo, towel blot, apply, wait four minutes while foils cool or a toner processes, then continue. Less product, less time, less frustration. That phrase guided us. Biology first haircare means you do not need seven layers to make hair look supported for a day. You repair the feel from within, then you use less styler after.

You bleached your own coarse black hair to fully bleached in one appointment to test the formula. Walk us through that day, what you felt, and what you ask a reader with bleached hair to notice in their own test?

My hair actually felt better after bleach with K18 than it did in its natural state. That is still the line people quote back to me, and it happened in one long salon appointment. My hair is coarse and black. We took it to fully bleached in one sitting, with the mask used as part of the service. I kept touching it because I expected stretch, mush, that cotton feeling at the ends. It felt more like hair.

If you are testing at home after bleach or highlights, do it with clean observation. Shampoo well, rinse, squeeze until it stops dripping. Start with one pump for short hair, more for long or dense hair, and add only if the hair drinks it up. Comb through with fingers or a wide tooth comb. Set a timer for four minutes. Do not rinse. Then notice how it detangles, how it dries, how much styler you reach for. Hair happiness is a way to build confidence, and confidence here means you can comb through without bracing. If your scalp itches, if hair is shedding in clumps, or if breakage is severe, pause and see a dermatologist before you keep processing.

What would you do if you did not have to worry about damage?

Suveen Sahib

You say K18 has revolutionised the industry because it has liberated hair expression. What does that look like on a real head that wants color and health at the same time?

K18 has revolutionised the industry because it has liberated hair expression. What would you do if you did not have to worry about damage. That question sits behind every formula. Too many people were told to choose. Stay natural or accept breakage. Go blonde or keep length. We refuse that choice.

On a real head it looks practical. A client with fragile blonde can go a little brighter without living in a mask for an hour. A teenager trying copper for the first time can shampoo, treat for four minutes, then air dry with a little oil on the ends. A barber client with bleached texture can keep the cut sharp because the hair combs through instead of snapping at the line. Nature is the best designer, and we have found that by understanding the biology of hair you can achieve true hair health and hair expression with less product, less time, and less frustration. Less time in the chair, fewer bottles on the ledge, more of the color you asked for.

Your towel customers learned to blot, not rub, and to get out of wet swelling faster. What is the exact at home routine for the mask, including shampoo, water temperature, amount, and what not to do?

Keep it simple and keep your hands gentle. Here is the routine we teach.

First, shampoo well with lukewarm water. Rinse clean. Skip conditioner before the mask because conditioner can get in the way. Second, towel blot or squeeze until hair is damp, not dripping. Third, start small. One pump for short, fine hair. Two to three pumps for medium to long hair. Add one more only if ends still feel hungry. Fourth, work from ends up, finger comb through, then leave it for four minutes. Do not rinse it out. Style as usual.

A few notes from the chair. Use lukewarm water rather than very hot water, which can leave hair feeling rougher. Pat dry instead of rubbing. If you section dense coils or long hair into two to four parts, you will spread the mask more evenly and use less. Give any scalp serum two to three weeks before you judge it, and keep bleach touch ups on schedule instead of overlapping old blonde. If a child has itchy or flaring skin around the hairline, keep routines simple and ask a pediatrician.

The oil follows the mask as a finisher for frizz and shine. It is weightless when you dose it right. Warm one to three drops between palms, press and glide over damp or dry mid lengths and ends, then add half a drop more only where you see frizz. Too much oil is when hair strings together or looks wet at the roots. Start under, then build. For beards or short crops, one drop smoothed with the grain is often enough.

For coils, tight curls and wash day routines, how should sectioning, detangling and layering change so the same peptide does its work without buildup?

Coils and tight curls want patience and sections. Wash in parts if your hair shrinks and tangles. Shampoo one section at a time, rinse, squeeze, then clip the rest away. Apply the mask to damp hair in two to four sections, finger detangle from ends toward roots, then let the four minutes pass while you tidy the shower. Rinse nothing. Follow with your usual leave in or cream only if your hair asks for it, and keep that layer thin.

Buildup usually comes from too much product, not from the peptide itself. If hair feels coated, clarify gently, then return to the mask on clean damp hair. Lather well at the scalp with fingertips, massage in for about a minute, rinse fully, then repeat only if the scalp still feels oily. Pat dry with a towel or cotton shirt. Comb through with a wide tooth comb while damp. If you protective style, make sure hair is fully dry underneath before you braid or twist, and moisturize the scalp lightly between washes. Anyone with persistent flakes, pain or patchy loss should see a dermatologist.

Unilever signed an agreement to acquire K18 in December 2023, expected to close in the first quarter of 2024. What does that change honestly change for a household that buys for a partner, a teen and maybe a baby tub, and what stays the same?

The science came first, then we built the brand from there, and that order stays. The agreement signed on 22 December 2023, with terms not disclosed and close expected in the first quarter of 2024, gave us a larger home while we kept the biology first focus. For a household shelf it should mean the mask is easier to find and easier to repurchase, in salon, in retail and online. What does not change is the method. Shampoo, small amount, damp hair, four minutes, leave in.

If you buy for a whole household, keep routines separate and simple. A partner with a beard or short fade needs a pea sized amount of oil, not a mask serving. A teen starting color needs the mask after clarifying shampoo and a reminder not to mix bleach at home. A baby bath needs only gentle cleansing and a pediatrician approved moisturizer, not a repair treatment. Doing more with less also means buying less. Finish one bottle, note what worked, then replace. Hair like new is not about many steps. It is about the right step, repeated.

If someone has ninety seconds and a tight budget, what is the single method you want them to keep, and how does Biomimetic Hairscience fit into a Sunday routine without shame about bald patches, frizz or cost?

Keep the four minutes. If you do nothing else, shampoo clean, squeeze out water, use the smallest effective amount, wait the full four minutes, leave it in. That one habit supports the appearance of stronger, smoother hair more than adding three extra products in a rush. Biomimetic Hairscience just means we copy what biology already does well, then get out of the way.

On a Sunday, make it calm. Lather well, rinse, section if needed, treat, then detangle gently while the timer runs. Pat dry, air dry or blow dry on medium heat with distance. Finish with a drop of oil on ends if they look dry. You do not need to hide a thinning crown or a frizz halo to earn good hair. Work with what you have, cut to the health you have, color when the fiber feels ready. You cannot solve problems by being inside the problem, so step back, simplify, and let the routine fit a real morning.

Closing note from the desk

What stays with us is how physical this story is. A towel that taught blotting, a founder reading chemistry late, a lab in Portugal modelling keratin, a stylist watching foil work hold up, a man touching his own bleached hair in surprise. The method never drifts far from hands and water.

K18 set out to refuse a false choice between expression and healthy looking hair. Fewer steps, smaller amounts, four honest minutes. That is the work, shown plainly, for every gender and every hair type.

Product spotlight

Full-Size Leave-In Molecular Repair Hair Mask 50mL, 75 dollars for 50 ml. A leave in mask powered by the patented K18PEPTIDE that supports the look of repaired bleach and color damage in four minutes. Shampoo, skip conditioner, apply to damp hair, wait four minutes, leave in and style. Start with one pump and add only as needed.

Molecular Repair Hair Oil, 65 dollars for 30 ml. A weightless biotech oil to strengthen the look of hair, reduce the appearance of frizz at two levels of fiber, and improve shine. Warm one to three drops, press through damp or dry mid lengths and ends, and keep roots light. Use after the mask or alone to finish.