What's In Dandruff Shampoo? Chemist Breaks Down Head & Shoulders Ingredients | WSJ Label Lab

TL;DR

Head & Shoulders Classic Clean fights dandruff with 1% pyrithione zinc, while surfactants remove dirt and oil and dimethicone helps seal the hair cuticle and retain moisture. Blue 1, Red 33, glycol distearate, preservatives, and a proprietary fragrance provide color, appearance, product stability, and scent. Read on to understand what each ingredient does and why foam alone does not measure cleaning power.

Transcript

• This is what your hair looks like when it's dirty. - [Narrator] And this is what shampoo does to that dirt. - Surfactants form these micelles around the dirt, which is what grabs onto dirt and oil. It's like, no, no, I don't wanna go. That was the dirt. It's screaming for its life. (laughs) - [Narrator] Erica Douglas has been a cosmetic chemist f... Read More

Key Insights

• ☢️ Pyrithione zinc is a common active ingredient in anti-dandruff shampoos, effectively combating dandruff caused by fungal growth.
• 😌 The cleansing power of shampoos lies in surfactants, such as sulfates, which remove dirt and oil from hair and scalp.
• 👱 Silicone ingredients, like dimethicone, can seal the hair cuticle, retain moisture, and do not typically cause build-up.
• ❓ Synthetic colorants, such as Blue 1 and Red 33, are used for aesthetic appeal but have some concerns regarding their potential as allergens.
• 👶 Fragrance formulations often contain a multitude of undisclosed ingredients, and a new law could require allergen disclosure on labels by 2024.
• 🥺 Shampoo formulations consist mainly of water, which can potentially lead to microbial growth if not properly preserved.
• ✋ Various preservatives, like sodium benzoate, are used to prevent microbial growth, but some combinations may have a higher incidence of skin allergies.
• 📈 The pH of Head & Shoulders Classic Clean Shampoo falls within the standard range, although it is on the higher end.
• 🍻 The absence of parabens in the shampoo addresses concerns about their potential links to cancer, but further scientific evidence is needed for conclusive conclusions.
• 😨 Adding more conditioning and moisturizing agents could enhance the functionality and control of the shampoo for better hair care.

Questions & Answers

Q: What ingredients are in Head & Shoulders Classic Clean dandruff shampoo?

The formula includes 1% pyrithione zinc for dandruff, surfactants for cleansing, and dimethicone to help seal the cuticle and maintain moisture. It also uses Blue 1 and Red 33 for color, glycol distearate for a pearl-like appearance, preservatives such as sodium benzoate, and a proprietary fragrance.

Q: How does pyrithione zinc help fight dandruff?

Pyrithione zinc is one of the most common active ingredients used to fight dandruff. It targets dandruff associated with Malassezia, a fungus that feeds on scalp oil.

Q: How much pyrithione zinc is in Head & Shoulders Classic Clean?

The Classic Clean formula contains 1% pyrithione zinc. The FDA allows up to 2% in products like this shampoo that are applied and then rinsed off.

Q: What do surfactants do in dandruff shampoo?

Surfactants pull dirt and oil from the hair and scalp by forming micelles around them. The chemist identifies a primary surfactant and cocamidopropyl betaine as the secondary surfactant in this formula.

Q: Does more shampoo foam mean better cleaning?

No, the amount of foam does not determine how well a shampoo cleans. Some surfactants create abundant foam while milder ones may create less, so foam mainly serves an aesthetic purpose.

Q: Does dimethicone cause buildup or weigh hair down?

The chemist says the claim that silicones weigh hair down or leave buildup is not accurate. Dimethicone can remain on hair to seal the cuticle and maintain moisture, but it comes off when shampoo is used.

Q: Why is Head & Shoulders Classic Clean light blue and pearly?

Blue 1 and Red 33 create the shampoo’s light blue color. Glycol distearate acts as a pearlizing agent that gives the formula its pearl-like appearance, while the exact colorant ratios remain proprietary.

Q: What is disclosed about the fragrance in Head & Shoulders Classic Clean?

The label lists only fragrance, whose formulation can sometimes contain 30 or 40 ingredients and is often proprietary. Head & Shoulders lists more than 20 ingredients from the Classic Clean fragrance formulation online, and the chemist describes its scent as having floral and aquatic notes.

Summary & Key Takeaways

• Head & Shoulders Classic Clean Shampoo uses pyrithione zinc as an active ingredient to combat dandruff caused by Malassezia fungus.

• The shampoo relies on surfactants to cleanse the scalp by forming micelles around dirt and oil, regardless of the amount of foam produced.

• Silicones help maintain hair moisture, although they have been wrongly criticized for causing build-up. Synthetic colorants and fragrance remain proprietary, but regulations may require disclosure in the future.