Scientist explains: What everyone gets wrong about sulfates in shampoo

Summary

In this video, Michelle from Lab Muffin Beauty Science debunks common myths about sulfates in shampoos. She explains that hair science is complex due to the diversity of hair types and the sparse academic research. Michelle clarifies that the effectiveness of a shampoo isn't solely dependent on the presence of sulfates but on the overall formulation. She emphasizes that the product's intended purpose, such as clarifying or color protection, is more indicative of its performance than whether it's sulfate-free or not.

Takeaways

• 💇‍♀️ Many people misunderstand sulfate-free and sulfate-containing shampoos; both don't guarantee specific results for hair cleaning or protection.
• 🧪 Hair science is complex, more so than skincare, because hair is incredibly diverse in structure and response to products.
• 🌀 The shape of hair strands (straight, curly, coiled) significantly affects how hair reacts to products and care routines, such as wet versus dry detangling.
• 🌧️ Environmental factors like humidity can affect hair's behavior and product results, making hair studies hard to generalize.
• 👩‍🔬 Hair science is sparse, with evolving knowledge and inconsistent terminology, even among academic studies.
• 🧴 The overall formulation of hair products (not just individual ingredients like sulfates) determines how well they clean or protect hair.
• 🔍 Predicting how a shampoo will perform based solely on ingredients like sulfates or pH is too simplistic; the entire formula matters.
• 🎨 A study showed that a sulfate-containing shampoo could strip hair dye less than some sulfate-free alternatives, challenging popular myths.
• 🧼 Foam in shampoos and other cleaners doesn't necessarily correlate with better cleaning power; it's often about consumer perception.
• 📊 Reviews from people with similar hair types are valuable when choosing a shampoo, as trying it out on your own hair is the best way to know how it works.

Q & A

What is the main point of confusion regarding sulfates in shampoos according to the speaker?

The main point of confusion is that people generally misunderstand the role of sulfates in shampoos, with some believing sulfate-free shampoos are less damaging while others think sulfates are necessary for effective cleaning. The speaker argues that both views are oversimplified and not based on the complex chemistry involved.

What does the speaker claim about the state of academic hair science?

The speaker claims that academic hair science is 'a mess' due to the diversity of hair types, sparse scientific knowledge, and the complexity of hair's interaction with various products and environmental factors.

Why does the speaker say that hair science is more complex than skin science?

Hair science is more complex than skin science because hair is more diverse, with different shapes and types responding differently to hair care products. Additionally, the way hair interacts with water and other factors introduces more variables that affect how hair products work.

What is the role of surfactants in shampoos, as explained by the speaker?

Surfactants in shampoos have a dual nature, with a water-loving head and an oil-loving tail, which allows them to help oil and dirt mix with water so they can be rinsed away, resulting in clean hair.

What are the four different ways shampoos clean hair at a microscopic level mentioned in the script?

The four ways are depicted as microscopic processes where surfactants interact with hair to clean it without undergoing a chemical reaction. These are supramolecular processes involving molecular choreography, and they likely occur simultaneously to varying extents.

Why does the speaker argue that the pH of a shampoo is not a meaningful indicator of its effectiveness?

The speaker argues that the pH is not a meaningful indicator because the overall formulation of a shampoo, including the interaction of multiple surfactants and other ingredients, is much more complex and influential on cleaning effectiveness than just the pH level.

What is the 'circular reasoning' the speaker refers to in the context of sulfate-free shampoos?

The 'circular reasoning' refers to the assumption that sulfate-free shampoos are gentle and less stripping because formulators design them to meet consumer expectations based on widespread myths, rather than because sulfates inherently cause more stripping.

Why does the speaker say that foaming is not a reliable indicator of cleaning effectiveness in shampoos?

Foaming is not a reliable indicator because it depends on how well a product interacts with air and traps air in a thin film, whereas cleaning effectiveness depends on interaction with oil and dirt. These are two different supramolecular processes with no direct correlation.

What does the speaker suggest as a better approach to choosing a shampoo than focusing on whether it contains sulfates or not?

The speaker suggests looking at the shampoo's intended purpose, such as 'clarifying' or 'color protection,' and reading reviews from people with similar hair types. Trying the shampoo on one's own hair is also recommended to determine its effectiveness.

What is the speaker's background, and why does she feel qualified to discuss hair science?

The speaker, Michelle, has a PhD in chemistry and is a cosmetic chemist. She usually discusses skincare science but has been paying more attention to hair science, which qualifies her to discuss the complexities of hair care products.