Did you know that even though the hair on your head is dead, it is anything but static. Each strand or hair fiber is actually home to many many layers, each with their own complex interactions, bond, and connections.

Hair is a dynamic, constantly moving structure mostly made up of protein, or amino acids held together by bonds. Inside your hair, different types of hair bonds are constantly forming, breaking, and reforming. Like, right now, as you read this. 

All these chemical interactions change your hair’s strength, elasticity, and shape, so they’re pretty important to how your hair looks and feels. In short: intact bonds = healthy hair. 

Not all bonds are created equal, each plays its own role in your hair health journey—and can break at different points of your routine. There are numerous types of bonds and intermolecular forces that make up molecules, including the proteins in hair: covalent bonds, ionic bonds, hydrogen bonds, Van der Waals forces, and hydrophobic interactions. All of them work together to create optimal hair strength. Each type of force functions a bit differently, and each bond breaks and reforms under different conditions, so the more bonds that remain intact, the better shot you have at keeping hair strong + healthy through daily styling, chemical services, and heat damage. Let’s dive in to 3 of these key players—covalent, ionic, and hydrogen bonds.

This temporary bond is the weakest of the 3, forming with hydrogen atoms and usually nitrogen, oxygen, or fluorine atoms between neighboring keratin chains. They easily break and reform to give hair its shape. Ever notice how hair changes after washing with water or being in a humid climate? These water molecules bond with the amino acids in your hair, breaking the hydrogen bonds between keratin chains causing shape shifting and often, frizz.

Heat styling also impacts hydrogen bonds, causing them to break and reform in a new position.  Like straightening curly hair with a flat iron, heat changes the shape of your hair into a new style. So when you go to wash, style, or expose your hair to humidity, hydrogen bonds are the first to break, modify, and reform. 

This bond is stronger than hydrogen bonds, responsible for about 1/3rd of your hair’s strength. It forms from an electrostatic attraction between negatively and positively charged amino acids (aka ions). When your hair is exposed to high pH from water, chemical services, or even haircare products, these ionic bonds break. 

These bonds are the most durable of the 3, forming between atoms that share electrons with each other to provide structure and shape to the hair. There are different types of covalent bonds, but two are especially important in hair—disulfide bonds and peptide bonds. Disulfide bonds primarily connect separate polypeptide chains along the x-axis or width of the hair fiber. They bond between the sulfur atoms of amino acids, and break when they’re exposed to chemical services, oxidizing agents, and excessive heat or environmental factors.

Peptide bonds join individual amino acids together like beads on a string to create those long polypeptide (keratin) chains—the source of hair’s core strength + elasticity along the length of hair (y-axis). When you bleach your hair, get a chemical service in the salon, or expose it to significant heat, UV, or pollution, these peptide bonds break and compromise your hair’s overall structure and health.

While all of these bond types play a role in your hair health, without peptide bonds there can be no proteins, so these are extra special in creating the WHAT—i.e. keratin chains in the cortex—that gives your hair its core strength and structure. Hydrogen, ionic, and disulfide bonds are some of the ways HOW the keratin chains are stabilized, working together to create the strong, resilient proteins that make up hair. Unfortunately, daily brushing, styling, chemical services, product pH, and even exposure to the environment can cause these bonds to break—leaving your hair dull, dry, and damaged. When color and bleaching damage is in the mix, the damaged internal structure is even more vulnerable to breakage.

So, how do you repair these broken bonds? You could skip the heat styling, and other damaging habits to help keep your hair bonds intact—but doesn’t leave much for hair expression.

Think of bond builder technology as putting a cast around a broken bone or stitches over a deep cut— it's a temporary fix that helps stabilize an injury, but isn’t alone enough to repair it. Bond-building technology addresses a single type of bond, often disulfide bonds, which interact at isolated points along the width of the hair fiber, but it ignores the bigger picture of integrating multiple points of interaction to reconnect breaks in peptide bonds and reinforce structure on the length of hair. You need to restore more than just disulfide bonds to get lasting, improved, holistic hair strength and elasticity—and for true hair repair. And because of the shifting nature of each type of bond, focusing on just one type means that repair agent is vulnerable to more easily being washed away.

That’s where molecular repair comes in. Going deeper to reconnect multiple types of bonds on the molecular level for true damage repair, molecular repair addresses breaks along both the length AND width of hair. The secret is in our patented K18PEPTIDE™, which integrates with and reinforces the structure of hair proteins in the cortex, working in a different way and place in the hair to reconnect broken peptide bonds for renewed strength + elasticity. In the process, hydrogen and disulfide bonds are also reconfigured for strength renewal across 2 points of the hair fiber instead of just one for more effective, comprehensive repair.

This holistic approach to damage repair is like doing surgery on a wound, healing the damage at its core. The result is restored strength, softness, smoothness, and bounce—finally putting an end to the cycle of damage and surface-level results. And since our peptide is biomimetic (as in it mimics hair’s biology), it stays in hair for lasting + progressive results after just one use. Nice. 

You can use K18REPAIR™ with every client + service to clinically reverse hair damage in just 4 minutes after bleach + color, chemical services, and heat. This brings your client’s hair back up to 91% virgin strength + 94% virgin elasticity* 

So go ahead and heat style, color, and do it for the trend. Molecular repair has your services, and your client’s hair health handled with immediate + lasting holistic damage repair—and maximum expression. 

*Results observed in a clinical study while using mist and mask as part of a bleaching treatment. Results may vary depending on hair type, quality, and history