When it comes to hair washing, my modus operandi is pretty straightforward: Get into the shower, wet my entire head, apply shampoo all over, and rinse. Then, apply a conditioner or hair mask. The end.
A routine procedure, simple enough. Or, so I thought. Because as it turns out, I’ve actually been washing my hair all wrong. And, not just that—I’ve been using the wrong shampoo, too.
Mind-blowing information, at least for me. And maybe for you, too. It comes courtesy of Lena de Pons, a pharmacist based in Spain who just so happens to be an expert on the science of skin-, hair-, and scalp-care. She advocates for the importance of knowing how—and most importantly, with what—to wash our hair. And, she swears that the secret to getting what she calls “a hair glow” is actually all about the type of shampoo we’re using and not much more. Her main mane recommendation? Use a shampoo with an acidic pH in order to seal the cuticle and help reflect light.
How an acidic shampoo seals the cuticle to add shine
If a shampoo with an “acidic pH” sounds like it would fry your hair, it might be helpful to first get a baseline understanding the structure of your hair. “The hair cuticle is made up mainly of keratin; it is the outermost layer of the hair, and therefore the one that protects the internal structures of the hair—the cortex and the medulla—from physical and chemical damage,” de Pons explains. “If we look at the cuticle under a microscope, we will see that it is made up of a set of flat cells that, due to their arrangement, are very reminiscent of the tiles on a roof.”
This visual analogy is helpful when thinking about how pH affects our hair. “The pH of the environment we are in can completely modify the structure of our hair. If we place ourselves in a pH gradient from acidic to alkaline, we will see that in a completely alkaline pH—the opposite of acidic—the cuticle of the hair is completely open,” de Pons says. “With an alkaline shampoo, the ‘shingles’ of the cuticle become completely perpendicular, looking more like the branches of a fir tree projecting from the trunk.”
The effect of pH is super obvious when hair is bleached or subjected to permanent hair color treatments: “Ammonia, which is alkaline or basic, opens the cuticle to allow bleach or dye to penetrate the hair cortex. The application of shampoos, conditioners, masks and other treatments—which are generally acidic—allows those “shingles” of the cuticle to contract,” de Pons says. “When the tiles are stacked alongside each other so much so that they become almost imperceptible, which makes our hair shine. In the end, it’s the smoothness of the cuticle that reflects light.”
Your new ritual for shampooing
“When a formulator creates a shampoo, he thinks about the correct application of the product. As a user, it’s important to use that formula as it’s intended; as it has been designed to be used,” de Pons explains, adding that most shampoos are actually formulated to clean the scalp and therefore should be applied to the scalp and nothing else. “Advertising has done a lot of damage in this sense; we tend to imitate the fancy gestures seen on television commercials. We scrub and scramble our hair, which is completely incorrect,” reveals de Pons.
So, no more scrubbing. But why, exactly? De Pons says it again comes down to the actual structure of the hair. “Physiologically, the root of the hair has nothing to do with the rest of it; the pH is different there than on the ends, and the amount of sebum is also completely different.”
To that end, she says the correct modus operandi for hair washing is this: first, take care to ensure that all your hair is fully wet before applying just a small amount of shampoo. Then, emulsify the shampoo before applying it to create a foam and with your fingertips, massage that foam into the scalp for a minute or more. “When you rinse the shampoo, it will slide down the rest of your hair, cleaning the ends on its way to the drain.”
And don’t worry about your hair not getting clean enough: “Your hair will not stop being clean by doing it this way,” de Pons explains. “In fact, after just a few correct uses you will notice that the appearance of your hair improves significantly.”
How to know which shampoo is right for your hair?
The million dollar question has a simple, logical answer. “This is the same question that we must ask ourselves when forming our skincare routine—we must be clear about our needs and objectives,” de Pons says. “Therefore, we should choose a shampoo according to the needs of the scalp and choose the conditioner and the mask according to the needs of the actual hair.”
Are shampoos with parabens and silicones bad?
When it comes to the question of parabens—and if they’re actually harmful for hair—the expert is clear: “Absolutely not,” she says, noting that the European Multidisciplinary Scientific Committee (SCCS), which is solely dedicated to investigating the concerns of European cosmetics consumers, has done “tons of paraben testing” and still hasn’t found cause for concern. “Europe has some of the strictest regulations that exist for formulating and bringing foreign cosmetics to the market,” de Pons explains. “After numerous tests and studies, there is no evidence that parabens are bad.”
Question answered, but it remains to be seen if the same is true for silicones. “Silicone is a separate issue,” de Pons says. “First we must understand that there are two types: volatile silicones and non-volatile silicones. Volatile ones, as their name suggests, evaporate quickly after application; they disappear and do not remain in the hair leaving a feeling of hydration and even freshness. Non-volatile silicones, on the other hand, remain in the hair.” Because they add weight to the hair, these silicones are best used by those with straight hair but should be avoided by those with curly hair who don’t want their spirals to lose definition.
De Pons says there’s another problem with silicones—one that’s more visually displeasing than actually unhealthy. “There is the infamous build-up effect with silicones. If you use them too often, eventually the hair can appear dirty.” She recommends removing the build-up with a weekly scalp exfoliation which, when rinsed, will slide down the length of the hair to remove the excess. “Silicones are not bad and have clear aesthetic benefits, but we must take this step into account at least once a week,” reports the expert.