Over time the outer layer of hair, the cuticle, naturally erodes away, breaks and lifts. These are points of weakness where the hair is likely to break. I like to refer to these gaps in hair as “hair potholes” (note that this is not a technical term!).
Bad hair management, e.g. excessive use of heat and rough styling equipment increases the likelihood of such potholes occurring.
Most conditioners help to prevent such damage but at the moment none actually repair it. Scientists are working to solve this problem; just like a broken or fractured bone can be completely healed they want to do the same with damaged hair.
What would be needed to repair the hair would be something that permanently fills the hole. At the moment, conditioners fill these gaps but after a couple of washes those holes and gaps are gaping open again. It’s just like having a road with potholes and filling those holes with sand, when the rain comes you’re back to square one!
Anyhow, the first major move in technology to repair hair is something called Polyelectrolyte Complex, PEC. It consists of a negatively charged ion called PVM/MA polymer and a positively charged ion called Polyquaternium-28.
How does PEC work?
Instead of just coating hair like most conditioners do it penetrates the hair and seals it from inside. When PEC penetrates hair and dries the split end is permanently fixed – the pothole has been filled with tar!
As the technology is still in its infancy I can’t ascertain the strength of this fix. That is, does one application fix that hair strand permanently or is re-application needed to maintain the same broken strand every so often. Also, does one application fix all the damage in one hit or are several rounds of conditioning needed to get to all the damaged hairs? What factors work against PEC? E.g. does blow drying and straightening hair with heat cause the fixed hair to get damaged again more quickly? Many questions remain open and more tests are needed to confirm this.