Everyone Is Talking About Bond Builders—Here’s What You Need to Know
This ultra-reparative category of products is rising in popularity, but according to the experts, not all bond builders are what they claim.
Bond repair. Bond building. Bond maintenance. You’ve undoubtedly heard one or all of these terms at your salon, on TikTok, or from one of your favorite hair-care retailers. Until recent years, you could only access the ultra-reparative category of products during a service with a licensed professional. But the last year, in particular, has brought about a breadth of new products at every price point that you can purchase in stores or online for use at home.
“Originally, bond builders were considered ingredients that repaired disulfide bonds within the hair structure,” says cosmetic chemist Perry Romanowski. “These are the bonds that give hair strength and they can be broken down when you have chemical treatments like hair coloring, relaxers, or perms.” Theoretically, by repairing these bonds, bond builders could restore the integrity, strength, and appearance of hair.
But with the proliferation of bond-building products in the market—and at more accessible price points—experts are skeptical that all bond builders are created equal. “Whenever a hero product comes along and carves its place in the marketplace, other companies will take note of that product’s success,” says New York City-based hairstylist Devin Toth. “Those companies then carve out space for that new category in their own lines.”
That has both good and bad consequences. The good? More accessible price points. The bad? The market is flooded with bond builders that may not actually “build,” especially since there isn’t anyone regulating that term. “Companies got wise to the fact that the term ‘bond builder’ doesn’t have a legal meaning,” says Romanowski. “So, they’ve taken to calling things that might electrostatically bond to hair ‘bond builders.’ But this is pretty much how all hair conditioners work.”
So how can you tell the difference between the real deal and a deep conditioner? (Deep conditioners are also good for your hair, but they are not a “bond builder.”) We asked the experts to break down the bond builder trend and what to look out for if you’re hoping to repair damage.
What are bond-repair products?
Your hair is naturally made up of a bunch of chemical bonds too small for the eye to see. Bond-repair products are meant to help fix them and improve hair health by using similar chemistry.
More specifically, bond builders were created to target three different types of chemical bonds that naturally exist in hair, according to Missouri-based colorist Colissa Nole. Disulfide is the strongest bond (also known as an S-S bond) and “stabilizes your protein chain,” she explains, adding that protein chains contribute to overall hair health and elasticity.
Second, on the bond chain of command are hydrogen bonds, which Nole says are “responsible for your hair’s resistance to external elements such as water and heat and holding the texture and shape of your hair.”
Salt bonds, or ionic bonds, are the weakest type of the three; they break when the hair is too alkaline or too acidic, which can then cause the hair to break or shed easily. Bond-repair products are often made with pH level in mind to strengthen those salt bonds and further contribute to healthy hair, says cosmetic chemist Ginger King.
OK, but how do bond builders work?
“Bond builders work by rebuilding the S-S bonds,” says Robinson. “Bond builders like that in Olaplex No.4P Blonde Enhancer™ Toning Shampoo, put a compound between the sulfurs so instead of your hair’s natural S-S bond you have something like an S-bond builder-S-bond. It’s supposed to work well as an S-S bond, and that should then theoretically restore the hair’s strength and resilience.”
For Olaplex, one of the first brands to become synonymous with bond building, amino acids are also key ingredients thanks to (prepare for a big, complicated term) bis-aminopropyl diglycol dimaleate, a patented conditioning ingredient. “The dimaleate part helps to prevent disulfide bond damage, often seen during bleaching,” King says. On top of those bond repairing qualities, many of Olaplex’s products also deliver deep conditioning to the hair via jojoba seed oil and aloe for softness and smoothness.
K18’s products like the Leave-In Molecular Repair Hair Mask achieve similar results with a different ingredient. King explains: “They have their own patented 18-peptide technology—peptides are a chain of amino acids, which do create a kind of bonding effect.”
Do bond builders make a difference for damaged hair?
Yes and no. “Bond builders work to a certain extent — particularly in conditioning damaged hair,” says board-certified dermatologist Ariel Ostad, MD, which in turn will strengthen it considerably. “But they may not be able to revive dead hair fully. The best way to do that is to get a trim and then use a proper hair care routine to maintain the new healthy hair growth.”
It is, in effect, a bandage. Romanowski agrees: “I’m skeptical that bond builders help very much, even if they do create some new hair bonds. I think it is just a bit of ‘science washing,’ because when you break the hair bonds you rearrange the molecules in such a way that you can’t easily restitch bonds in the proper spots.” It seems a majority of the effectiveness of these products are the conditioning ingredients, he adds, which can indeed improve the look and feel of damage.
If you have very bad damage, or even hair loss, see a dermatologist to talk about scalp and follicle health—creating a healthy environment for new growth means healthier hair as it grows.
How should I decide which bond repair products to use?
If you want to give bond repair a try, go for it — when used properly, these products won’t actively hurt your hair. Too much protein can dry out your hair, says Dr. Osted. But typically, the proteins used in hair products are hydrolyzed proteins, meaning they are water-soluble, says Romanowski. “Unless you are using a leave-in product, nearly all of the protein is simply rinsed down the drain. Again, it is just a compelling marketing story that proteins are helping your hair.”
But the “bond building” products on the market today can still provide nourishing conditioning ingredients to damaged hair, like behentrimonium chloride, dimethicone, and silicones, which Romanowski says “are really good at mitigating hair damage.”
When in doubt, ask your stylist. “Sometimes people aren’t sure of what products to use, and make assumptions about what products they need which can cause more problems,” says New York City-based hairstylist Stephen Thevenot. “Your stylist has a wealth of knowledge and can help you come up with a plan to treat your hair. There likely isn’t going to be a one-product-fix-all solution.”
Rinse-Out Treatments
Toth appreciates that the Aveda Botanical Repair Bond-Building Flash Treatment rinse-out treatment offers “ hydrating ingredients like avocado, coconut, and green tea seed oils.” It also smells like a lush Balinese garden, which is reason enough to work this into our routine.
Shampoos and Conditioners
The L’Oréal Paris EverPure Sulfate-Free Bond Strengthening Shampoo smells like a fancy French salon without the fancy prices. (Now that’s chouette.) Even better is how it can deeply condition your hair at just the first step of your routine — eliminating the need for another treatment. (Though, we won’t discourage you from indulging in a hair mask just for self-care.)
Leave-In Treatments
The Garnier Fructis Hair Filler Moisture Repair Gel-Cream leave-in treatment has a lightweight gel texture and thanks to hyaluronic acid, is particularly healing for dry or frizzy hair types. “I love that it gives hairstyles some hold and will help to define curls,” says Toth. While it’s not a bond builder (or “filling” any gaps, perse), it can help to improve visible damage.
There’s a lot of guesswork when it comes to finding ingredients that your hair responds to, so we love treatments that can be adapted to your hair type (straight and wavy or curly and coily) via customizable shots.
It’s not magic
Bond builders can help improve the look and feel of damaged hair, but they’re not a one-step fix. Whether you reach for a professional treatment or a budget-friendly formula, knowing what these products actually do (and don’t do) will set you up for better hair days ahead.
