In poor condition: Dermatologist disagrees with products claiming to replenish hair shaft component

Key Points

According to Zoe D. Draelos, M.D., several manufacturers of high-end hair products have developed conditioners they say artificially replace 18-MEA after chemical processing.

Unfortunately, these conditioners cannot replace the lost natural- conditioning layer permanently, but consumers may see a temporary partial restoration of the sheen and resilience that their hair had before chemical treatment.

"When hair grows naturally, it has a lipid layer on top of it, like sebum on the skin," says Dr. Draelos, medical director of Dermatology Consulting Services here.

"This layer, 18-MEA, is a hydrophobic layer that is protective over the hair. It is bound to the cuticle. The hydrophobic lipid neutralizes static electricity, prevents water from entering the hair shaft, adds shine to the hair shaft, and prevents other sorts of damage, such as from shampoos and conditioners," she says.

Dr. Draelos says the 18-MEA layer in the hair and the layer of sebum in the skin have similar functions - to act as a protective barrier.

Chemical processing removes 18-MEA and, therefore, damages the cuticular scale, just as harsh soaps damage the intracellular layer of sebum in the skin, Dr. Draelos tells Dermatology Times.

The loss of the 18-MEA layer is permanent, she says. Once 18-MEA has been destroyed, the only lasting way to replace it is to grow out the chemical process. The new hair coming in will have 18-MEA - so long as it, in turn, is spared chemical processes.

The destruction of the 18-MEA layer is the reason why hair that has been dyed, permed or straightened never has the same sheen or overall healthy appearance as hair that has not undergone such processes.

Product claims

Dr. Draelos says that some companies that focus on expensive hair products have taken advantage of the newly discovered 18-MEA and claim that their conditioners can replace this layer. Certain ingredients, such as berry extracts that contain fatty acids, are particularly emphasized.

However, she says, although the new conditioner may contain conditioning agents, the benefits are only temporary, washed away with the next shampoo.

"Once 18-MEA is gone, it's gone," Dr. Draelos says.

Despite the marketing claims, these newer conditioners accomplish the same objective as any other conditioner - to coat the hair shaft and smooth it so that it appears shiny and healthy, Dr. Draelos explains.

Advising patients

Dermatologists are in an ideal position to help patients understand the limitations of hair products purporting to replace 18-MEA, Dr. Draelos says.

"They're no better than any other conditioner," she says. "Patients need to know that you can't restore 18-MEA. When the layer is destroyed, the damage is permanent. You can never permanently replace it."

Dermatologists can encourage patients to be more discerning in their purchases of hair products, and they can take this approach one step further, Dr. Draelos says.

When doctors get the opportunity - before the chemical process occurs - they can ask patients to seriously consider the impact of chemical processes on the appearance of their hair.

"The hair will no longer resist static electricity or water," she says. Therefore, the hair will be more susceptible to both the "flyaway hair" phenomenon in the winter and the wilting of a carefully-sculpted coiffure in hot, humid weather.

"This is another way to explain to patients why their hair doesn't perform as well after a chemical treatment," Dr. Draelos adds.

An ounce of prevention

Dr. Draelos acknowledges that it may be unrealistic in a hair- conscious culture to expect consumers - primarily women - to forego all perms, dyes and straightening processes.

The next best choice may be for consumers to avoid retreating the same hair, and to let each process grow out before putting on a new one, she says. Extending the time between chemical hair procedures is the best way to optimize hair health.

"Each time you re-expose the hair to the same process, it's additive damage," Dr. Draelos explains.

Consumers should also be encouraged to use a conditioner of their choice after each chemical process so that the damage to the hair is minimal.

This preventive approach is a more effective way to maintain the hair's health than to try to reverse the damage with conditioners, Dr. Draelos says.