A shampoo aimed at visible flakes is a formulation exercise with a regulatory edge. The active has to reach the scalp, stay suspended in the bottle, survive the shelf, and stay within a permitted level that differs from one market to the next. The part that catches brands out is the last one, because a formula that is legal at home can be barred abroad.
This article covers the cosmetic actives used for flake control, how each behaves in pH and in colour, how the active is made to deposit rather than rinse straight off, and why the wording on the bottle has to stay at the level of appearance rather than step into a medical claim.
Why a flake-control shampoo is a formulation job
The visible flakes most users notice come from a scalp that is shedding faster than usual, and a cosmetic shampoo can help keep the scalp looking clearer by managing that surface. What it cannot do is cross the line into a pharmacological statement, and the formula and the label are built on opposite sides of that line.
The active is only half the work. It has to be dispersed in a surfactant base that itself is mild enough for frequent use, held stable through a warm warehouse and a cold shelf, and delivered to the scalp in enough amount to matter. A strong active in a base that splits or a bottle that clumps is a weak product.
The deposit step is where the cosmetic science sits. The active is often a fine particle or a metal complex, and getting it onto the scalp instead of down the drain is the difference between a formula that works and one that merely contains the ingredient. Our scalp care opportunity article sets out why brands are moving into this part of the aisle.
The actives on the permitted list
The cosmetic actives most seen in flake-control shampoos are zinc pyrithione, piroctone olamine, selenium sulfide, salicylic acid and sulfur. Each is a raw material with its own permitted level, its own pH window and its own look in the bottle, and the choice is a balance of all three rather than a pick of the strongest.
Zinc pyrithione and piroctone olamine are the two most common modern choices, with piroctone olamine the wider traveller because it stays permitted across more markets. Selenium sulfide is the heavier hitter and the more coloured one. Salicylic acid and sulfur are the older pair, still used where a simple, well-known system is wanted.
A sixth name, ketoconazole, sits outside this list for a reason explained later: it belongs to the medicinal category and is not a cosmetic raw material a brand specifies into a shampoo. The line between the two groups is the one that decides what a contract manufacturer can lawfully make.
Zinc pyrithione: where it stands now
Zinc pyrithione, often written ZPT, is a zinc complex that was for years the standard flake-control active in shampoos. It disperses as a fine white to off-white particle, it is used at a low percentage, and it gave a cheap, effective base that many value lines were built around.
Its position has changed by market. In the European Union the use of ZPT in cosmetics is no longer permitted, following the withdrawal of its biocidal approval, and a shampoo made for the EU shelf cannot carry it. Other regions still allow it within a set limit, so the same formula is legal in one place and barred in another.
The practical consequence for a brand is that ZPT is a market-specific active, not a default. A launch that may sell in the EU has to be built on a different active from the start, or reformulated per region, and the cost of doing that late is a withdrawn batch. The permitted level and the market status must be confirmed before the bulk is set, not after.
Piroctone Olamine: the widely used option
Piroctone olamine, sometimes known by its trade name Octopirox, is an ethanolamine salt that is permitted across a broad set of markets and is the active most often chosen for a globally sold flake-control shampoo. It is used at a low level, it is stable in the weak-acid to near-neutral window, and it stays clear in the bottle.
It suits a cosmetic claim because it is a known cosmetic raw material with a defined limit, and it does not carry the market baggage that ZPT now does. The formula still has to hold it in suspension and deliver it to the scalp, but the regulatory base is steadier than for the older complex.
The pH matters to its stability. Too alkaline and the solution can shift; too far and the deposit suffers. The formulator sets the buffer with the active in mind and checks the number after the preservative and the essence are added, because those move the pH more than the water does. Our compatibility testing guide covers how the bulk and the pack are screened together.
Selenium Sulfide: the strong, coloured one
Selenium sulfide is the most potent of the cosmetic actives and the most visibly present, because it gives the product a yellow to amber colour that cannot be hidden in a clear bottle. It is used at a low percentage and is kept in a suspension rather than a solution, because it is an insoluble particle.
The colour sets the pack. A selenium sulfide shampoo is almost always opaque, and the label shows the tint, because a user who expects a clear gel will read the colour as a fault. The suspension also has to stay uniform through the shelf, or the last fills are weaker than the first.
The deposition is good, which is why it earns its place, but the look and the handling cost more. A brand choosing it accepts a coloured product and a closer eye on the suspension stability, and the claim stays at the cosmetic level of visible flake control rather than anything stronger.
Salicylic acid and sulfur: the older pair
Salicylic acid is a keratolytic in higher pharmaceutical strength but a known cosmetic ingredient at the low level used in shampoo, where it helps loosen the surface scale so the wash carries it away. It is permitted within a set limit and is valued for a simple, long-understood system that regulators and buyers recognise.
Sulfur is the oldest name on the list and the most pungent, with a characteristic odour that the fragrance has to cover. It is used where cost and familiarity matter more than a clean scent, and it pairs with salicylic acid in some classic combinations aimed at a basic flake-control routine.
Both are stable and cheap, and both sit comfortably inside the cosmetic frame when used at the permitted level. The limit is the constraint, and the odour and the feel are the reasons a modern line often reaches for piroctone olamine instead while keeping salicylic acid as a co-active.
Ketoconazole and the regulatory line
Ketoconazole is a different class of substance. It is used in finished medicinal products that are authorised as drugs, and it falls under pharmaceutical rather than cosmetic regulation. For a cosmetic shampoo it is out of scope, and a contract manufacturer making a cosmetic line does not formulate it in.
The reason this matters in a brief is the wording. A brand that wants the benefit associated with that substance has to stay on the cosmetic side of the regulatory line, using a permitted cosmetic active and a claim about appearance, not a pharmacological statement. Crossing that line turns the product from a cosmetic into a medicated item that needs a different approval path.
The safe rule is simple: the cosmetic formula uses cosmetic actives, and any reference to a medicinal substance is left to the pharmacist and the market authorisation. We can build the cosmetic shampoo; the drug is a separate regulatory track that the brand confirms with the competent authority. The distinction protects the launch more than any stronger sentence on the label would.
Getting the active to deposit
An active that rinses off before it lands does nothing, so the deposit is engineered. A cationic polymer such as polyquaternium-10 or polyquaternium-7 carries a small positive charge that binds the active to the mildly negative scalp surface, holding it there through the rinse rather than letting it wash away.
The suspension is the second lever. Insoluble actives such as selenium sulfide or ZPT are kept from settling by a structurant and by a rheology that holds the particle in the body of the product. A formula that is too thin lets the active drop to the base of the bottle, so the early fills and the late fills are not the same product.
The third lever is the wash itself. A shampoo left on for a short contact time deposits less than one worked in and rinsed after a moment, and the pack direction teaches that contact without crossing into a use that reads as medicinal. The deposit and the direction are written as one brief.
Stability, pH and colour change
Flake-control actives are unforgiving on stability. A metal complex can react with a trace impurity and shift colour; an insoluble active can settle and cake; a pH drift can drop the active out of solution. The accelerated shelf study is not optional for this category, because the failures are slow and visible.
Colour change is the common symptom. A product that is pale on the line and amber after a hot month has a stability problem that the user reads as spoilage, even when the active is still present. The preservative, the chelant and the essence are all checked against the active, because each can nudge the colour.
The pH and the viscosity are watched together, because a thin product settles and a drifted pH discolours. The study is run at the chosen pack and fill, not in a generic jar, because the headspace and the wall change the result. Our stability testing article explains how the shelf life is set from those studies — note this link is for the method, and the market limit on each active is confirmed separately.
Compliance differs by market
| Active | Typical permitted limit | pH and system fit | Market and colour note |
|---|---|---|---|
| Zinc pyrithione | Low, market specific | Near neutral, particulate | Not permitted in EU cosmetics; confirm per market |
| Piroctone olamine | Low, broadly permitted | Weak acid to near neutral | Clear, widest market travel |
| Selenium sulfide | Low, fixed | Alkaline suspension | Amber colour, opaque pack needed |
| Salicylic acid | Low, cosmetic level | Acid tolerant | Simple, well recognised |
| Sulfur | Low, cosmetic level | Simple base | Strong odour, needs cover |
| Ketoconazole | Not a cosmetic active | Medicinal only | Drug track, outside cosmetic scope |
The table gives the shape of the choice rather than a figure to formulate to, because the permitted level is set by the market and the authority, not by the supplier sheet. Each active is confirmed against the destination before the bulk is locked.
What to put in the brief
- The target markets, because the permitted actives and their limits differ by region and decide the formula.
- The active or shortlist, with the understanding that ZPT is barred in some markets and ketoconazole is medicinal.
- The claim frame, kept to visible flake control and the look of the scalp, never a medical statement.
- The pack, because selenium sulfide needs an opaque bottle and the colour must be shown.
- The pH and viscosity target, so the active stays suspended and deposits through the rinse.
- The deposit system, such as the cationic polymer, and the contact time the label will teach.
- The stability expectation, including the hot and cold shelf the product must survive without colour shift.
- The documents needed for each market, listed early so the launch is not held at customs.
Where our capability fits
We build a flake-control shampoo on a permitted cosmetic active chosen for the destination markets, with the suspension, the pH and the cationic deposit system set so the active reaches the scalp and stays through the rinse. The stability and the colour are checked at the chosen pack before the run, and the claim is kept at the level of visible flakes.
We work with brands on private label (your brand on a proven base), OEM/ODM contract manufacturing, and full custom formula development — whichever matches where your brand is today. Our related lines include a bottled shampoo and body wash, an amino acid teen shampoo and a leave-in hair spray, each specified within its own cosmetic claim frame.
Tell us the markets and the claim you need, and we will set the active and the label to match. Start at our inquiry page, email capsulebiotech@163.com, or message the right team on WhatsApp: Capsule Series (capsules only) +86 158-7655-5319, Cosmetics Series (serum, hair care, body care, fragrance) +86 158-7655-5319.
General manufacturing information, not regulatory or legal advice. Active limits, market permissions and claim wording vary by product and destination and must be confirmed with the competent authority.