Ingredients to Avoid for Low Porosity Hair: Why That List Cannot Exist

If you searched for a list of ingredients to avoid, I know exactly what you were hoping for. A tidy set of names to scan for on the back of a bottle, so you could put the wrong products down and pick the right ones up without guessing.

I spent years looking for that list. I built my routine around it. And I want to tell you honestly why it does not exist, what the label can actually tell you, and what to read instead.po

THE SHORT ANSWER A product is the sum of a whole formulation, not a collection of separate ingredients. The same ingredient at the same concentration behaves completely differently depending on what it is sitting next to. That is why two products with almost identical labels can perform nothing alike, and why no avoid-list can predict what a bottle will do on your head. The label is a legal disclosure. It is very good at one job, telling you whether something you personally react to is present. It cannot tell you whether a product will work.

I Chased That List for Years

I came up through the Curly Girl Method, and the blacklist was the method. Sulfates out. Silicones out. Drying alcohols out. And oils, which Lorraine Massey came down on hard.

What that turned my hair care into was a scanning exercise. I would pick up a bottle in a shop and read the back of it looking for banned words. If one was there, I put it down. I was not asking whether the product was good, or whether it suited my hair. I was checking it against a list.

The oils part is the piece I still think about. I had a quiet sense that oils were doing something useful on my hair. I could not defend it, because I did not know the chemistry well enough to argue with an authority who was telling everyone that buildup came from oils and silicones. So I deferred, and I stopped using things that were probably helping me.

Here is the part that shows how much reach that idea had. Brands started reformulating around it. Sulfate free. Silicone free. Paraben free. Alcohol free. Whole product lines were built and marketed on the absence of things, because the market had been trained to shop by exclusion.

That is when the label stopped being an information surface and became a marketing surface. Once “free from” sells, the front of the bottle is designed around what is missing rather than what the formula does. And a formula defined by what it left out is not the same thing as a formula built to work.

What I did not understand at the time, and what nobody in that community had access to, is the thing this whole article rests on. A product is the sum of a whole formulation. Not a list of parts you can approve or reject one at a time.

Nobody Was Ever Checking

Here is the thing I did not know while I was standing in shops reading the backs of bottles.

Curly girl approved is not a regulated claim. There is no standard a product has to meet, no body that assesses it, and no requirement of any kind. Any brand can print it on any packaging. There was never an approving authority behind the phrase that organised how thousands of us shopped.

Sit with that for a second, because it reframes the whole exercise. I was not checking products against a standard. I was checking them against a preference, held by one person, which the market had adopted and which brands then printed on labels to sell to people who had adopted it too. The loop closed on itself and nobody along the way had to demonstrate anything.

The same applies to most of what looks official on the front of a bottle. Natural has no agreed regulatory definition. Neither does clean. These are positioning words, and the reason they exist is that they work.

This is not an argument for cynicism about every brand. It is a narrower point: an unregulated claim on the front of a bottle is not evidence, and it should not carry the weight I gave it for years.

Why the Same Ingredient Behaves Differently in Different Products

This is the mechanism, and once you have it, the rest of the article follows.

Ingredients in a formula are not independent. They change how each other behave. The clearest example in hair care is one that runs directly against the standard avoid-list logic.

Cationic polymers, the polyquaterniums, are frequently blamed for buildup. They are also the ingredients that control how much silicone deposits on your hair, and they reduce silicone buildup substantially rather than adding to it. Whether the silicone in your shampoo accumulates is determined less by the silicone being present than by what else is in the bottle with it.

So an avoid-list flags the silicone, misses the polymer that governs it, and gives you a verdict on a product that has nothing to do with how the product will behave.

The same logic applies everywhere. Concentration is invisible on a label, because ingredients below one percent can be listed in any order. Even if you knew the concentration, that would not tell you whether the ingredient is doing its job, because performance depends on pH, on the emulsion, on what carries the ingredient to the hair and what holds it there. Two products can contain the identical amount of the same active and one can be inert.

And a demonized ingredient being present does not make a formula harsh, just as its absence does not make a formula good. “Free from” tells you about a marketing decision, not about performance.

What Happens if You Actually Take Them Out

The avoid-list treats these ingredients as passengers, things a formula would be better off without. They are not passengers. They are usually doing the work.

A shampoo does not clean without a sufficient concentration of surfactant, and sulfates are among the most effective surfactants available. Take the preservatives out and you get a bottle in which bacteria and mould can grow, which is a genuine skin risk rather than a theoretical one. Take the silicones out and you lose the smooth, soft result people are trying to buy in the first place.

This is not a fringe position among people who study hair for a living. It is close to the default one. Formulators and hair scientists tend to want these ingredients in their own products, because they know what each one is there to do and what a formula gives up without it.

None of that means every formula containing them is good, or that nobody is better off avoiding a particular one. It means the categories were never the problem, and a formula built around what it excludes has given up tools rather than gained safety.

What a Label Can and Cannot Tell You

The ingredient list is not useless. It is just being asked to do a job it was never designed for. It exists because regulators require full disclosure, and it is genuinely excellent at that.

A label CAN tell you	A label CANNOT tell you
Whether a specific ingredient you personally react to is present. This is the reason the list is mandatory, and it is the one job it does perfectly.	Whether the product will work on your hair. Efficacy lives in the formulation, not in the roster of parts.
Rough order of concentration for the ingredients above one percent, which are listed high to low.	Actual concentration of anything, especially below one percent, where order becomes arbitrary.
Broad category signals. A conditioner leading with cetearyl alcohol and behentrimonium methosulfate is built around conditioning.	Whether an ingredient will build up on you. That depends on the whole formula, your water, and your wash routine.
Whether a product is likely to be light or rich, from what sits in the first five or six positions.	Whether a heavily marketed hero ingredient is present at a level that does anything at all.

Read that left column again, because it is the honest use of a label and almost nobody teaches it. If you know you react to a specific botanical, or you are avoiding a fragrance allergen, the label is your best tool and you should use it exactly that way.

A Word About Ingredient Checker Apps

A lot of people arrive at this topic looking for a tool that will scan a barcode and return a verdict. That demand is completely reasonable. The tools mostly are not.

The common design is to grade individual ingredients good or bad, then roll those grades into a score for the product, sometimes labelled with words like clean or toxic. Two problems with that, and they are structural rather than fixable.

The first is the one this whole article is about. Scoring ingredients one at a time and adding them up cannot describe a formulation, because formulation is precisely the part where ingredients stop behaving independently. A product assembled from individually acceptable parts can perform badly, and a product containing something on a blacklist can be excellent.

The second is that several of the best-known checkers are commercial businesses that also sell certification to brands. Brands pay to be listed as approved. That is a business model, not a scientific assessment, and the ratings frequently arrive with no citation to any source you could check.

None of this means you should not look ingredients up. It means you should look them up somewhere that shows its working.

Where to Actually Look Something Up

All of these are free, public, and citable, and they answer the three questions people genuinely have: what is this ingredient, what is it for, and is it considered safe at the level used in cosmetics.

FDA Cosmetics, for regulatory information and permitted use in the United States.
The Cosmetic Ingredient Review, a panel of scientists and government officials publishing full safety assessments as free downloadable reports.
CosIng, the European Commission database, for INCI names, declared function, and restrictions.
For the specific question of which silicones rinse out and which build up, the solubility work at Science-y Hair Blog is the most thorough public treatment available, and it is properly reasoned rather than scored.^[1]

The pattern worth learning is not a list of good ingredients. It is the habit of asking what a given ingredient is for, and then checking whether the source telling you shows where its information came from.

Worked Example One: Silicones Are Not One Thing

Silicone is the single most blacklisted word in curly hair care, and it does not name one ingredient. It names a family whose members do genuinely different jobs.

Type	What it actually does
Dimethicone	The plain, water-insoluble one. How it spreads and how thick a film it leaves depends on molecular weight: lighter versions are fluid and spread easily, heavier ones sit longer and form the occlusive film. Removed by almost any detergent.
Dimethiconol and other silanols	Coat the cuticle particularly well, which is why they show up in products aimed at the appearance of split ends.
Cyclomethicone family	Volatile. They help a product spread evenly and then evaporate, giving slip and a clean finish rather than a lasting film. Effectively a short-term conditioner.
Amodimethicone and the silicone quaterniums	Modified to carry a charge, so they bind preferentially to damaged areas rather than coating everything evenly, and are designed not to stack on top of themselves.
PEG or PPG-prefixed silicones	Generally water-soluble. Worth knowing that water-soluble does not mean water-rinsable, since an ingredient can dissolve in water and still bind to hair.

All five of those read as “a silicone” to someone scanning a label. Two of them are specifically engineered against the exact problem the blacklist was created to solve.^[1]

The practical answer to “is dimethicone bad for low porosity hair” is therefore not yes or no. It is that dimethicone comes off with essentially any detergent, that the only cleanser which struggles is one relying on decyl or lauryl glucoside alone, and that if your hair feels heavy the useful move is to wash it and see, rather than to ban a category.^[1]

Worked Example Two: How to Tell Whether a Product Contains Protein

This is one of the most asked questions in hair care, so here is the actual skill rather than a list to memorise.

Proteins on an INCI list almost always announce themselves with one of three markers: the word protein, the word amino acids, or the prefix hydrolyzed. Hydrolyzed wheat protein, hydrolyzed keratin, silk amino acids, hydrolyzed collagen, hydrolyzed quinoa. Once you know the pattern you can spot them without a checker.

Two things that pattern will not tell you, and this is the point.

It will not tell you how much is in there. A protein sitting eighteenth on a list, after the preservative, is present in a quantity unlikely to do much of anything.

And it will not tell you whether the protein has been modified into something else entirely. Hydroxypropyltrimonium hydrolyzed collagen, for instance, is a protein that has been given a positive charge, which makes it behave as a conditioning agent that binds to hair. Same protein, different job, because of what was done to it.^[1]

So you can absolutely learn to identify protein on a label. What you cannot do is predict from that identification whether the product will suit you.

Worked Example Three: Natural Does Not Mean Safer or Gentler

The natural-versus-synthetic split is the avoid-list in its most emotionally persuasive form, and it does not hold up.

Natural has no agreed definition. Regulators, formulators, and marketers do not share a standard for what qualifies, which is why the word can appear on almost anything.

More importantly, plant-derived does not mean low-risk. Botanical extracts are a leading cause of both irritant and allergic contact dermatitis in cosmetics, and a study of dermatology patients found around six percent of people using topical herbal products reported at least one adverse skin reaction.^[2][3] Essential oils are among the most reactive ingredients in the category, with dozens documented as capable of causing irritation.^[4][5]

There is also a consistency problem that synthetics largely do not have. A plant extract is a complex mixture that varies by region, season, and preparation. Adulteration and substitution are real: grape seed extract can be supplemented with peanut skin or pine bark, and in one analysis of commercial aloe powders from major suppliers, only three of nine samples contained satisfactory amounts of the bioactive ingredient.^[6]

None of this makes natural ingredients bad. Used with proper identification and sensible exposure limits, they are fine, and the standard applied to them is the same standard applied to synthetics.^[7] The point is narrower and more useful: the origin of an ingredient tells you nothing about whether it will suit you, which is exactly what this article has been saying about every other category.

The Same-Ingredient Test

Here is how to find out whether an ingredient is actually your problem, rather than assuming it from a label. It costs nothing and it settles the question properly.

Think of the ingredient you currently believe your hair does not tolerate. Then find a second product that contains the same ingredient in a completely different formulation. If you decided silicones were the issue from a heavy leave-in serum, find a rinse-out conditioner containing a silicone. If you decided protein was the issue from a reconstructor, find a regular conditioner with a hydrolyzed protein well down the list.

Use it on its own, change nothing else, and judge on the second and third wash days rather than the first.

If your hair does fine, the ingredient was never the variable. The formulation was, or the amount you were using was, and you have been avoiding an entire category for no reason.
If your hair reacts the same way again, you have learned something genuinely useful and specific to you, and you have earned that conclusion instead of inheriting it.

Most people who run this honestly discover the first result. That was my experience with oils, years after I had stopped using them.

WHY THIS MATTERS MORE THAN A LIST A blacklist is inherited from someone else. The result of this test is yours, it applies to your actual hair, and nobody can take it from you by publishing a new list next year. This is the same one-variable discipline every method on this site runs on: change one thing, wait, judge, repeat.

What to Read Instead: Function, Not Verdict

If you stop reading labels for banned words, what do you read them for? Function. What is each of these things here to do?

You do not need to know every ingredient. You need to recognise the handful of roles that make up nearly every hair product, and where they sit.

Cleansers. Surfactants that remove oil and residue. Their strength varies enormously, which matters far more than whether the word sulfate appears.
Conditioning agents. Positively charged ingredients that bind to hair and reduce friction, which is what actually makes hair feel soft and detangle. Behentrimonium methosulfate, cetrimonium chloride, and their relatives.
Fatty alcohols. Cetearyl, cetyl, stearyl. Thickeners and emollients that give a conditioner its body. Not drying, despite the name.
Emollients and oils. Slip, softness, shine, and a surface film.
Film formers and polymers. Hold, frizz control, and definition. This is also the category most likely to accumulate.
Humectants. Attract water. Useful in some conditions and counterproductive in others, which is a weather question rather than a good-or-bad question.
The supporting cast. Preservatives, pH adjusters, emulsifiers, fragrance. Necessary, mostly boring, and disproportionately feared.

Reading this way changes the question from “is this ingredient bad” to “what is this product built to do, and is that what I need right now.” That is a question a label can genuinely help with.

Frequently Asked Questions

So What Ingredients Should Someone With Low Porosity Hair Avoid?

None, as a category. What people describe as low porosity hair is usually hair in reasonably good condition, which tends to be easier to weigh down, so heavier products can sit on it. That is a question of product weight and how much you apply, not of specific ingredients being harmful. Porosity is a spectrum describing the condition of your cuticle rather than a type you belong to.

Is Dimethicone Bad for Low Porosity Hair?

No. Dimethicone is a widely studied conditioning agent that adds slip and shine and comes off with nearly any detergent. If a dimethicone-containing product feels heavy on your hair, that is worth acting on. The action is washing it out and trying a lighter product, not removing the ingredient from your life.

How Do I Know if My Shampoo Has Protein?

Look for the word protein, the words amino acids, or the prefix hydrolyzed. That will find nearly all of them. Bear in mind that spotting it does not tell you the amount, and that some proteins have been chemically modified into conditioning agents that behave quite differently from the plain version.

Are Ingredient Checker Apps Worth Using?

For finding out whether a specific ingredient is present, they are convenient. For judging whether a product is good, no, because a product is not the sum of separately graded parts. Be aware too that some of the best-known checkers sell certification to the brands they rate, which is a commercial relationship rather than an assessment.

Is “Curly Girl Approved” a Real Certification?

No. It is not regulated, there is no standard to meet, and no body assesses it. Any brand can put it on any packaging. If a product carries that phrase, it tells you the brand is marketing to a particular audience, and nothing at all about how the formula will behave on your hair.

Are Sulfate-Free and Silicone-Free Products Better?

Not automatically. Both describe what a formula lacks rather than what it does. A well-made sulfate-containing shampoo can be gentler than a poorly made sulfate-free one, and the reverse is equally true. Free-from language is a marketing position that exists because a large audience was trained to shop by exclusion.

Why Do Two Products With Almost the Same Ingredients Feel So Different?

Because concentration, order, pH, and the interactions between ingredients all shape the result, and none of those are visible on the label. This is the single most useful thing to understand about hair products, and it is the reason no avoid-list can work.

Is There Anything I Should Genuinely Avoid?

Anything you personally react to. That is what the ingredient list is for and it does that job well. Beyond genuine sensitivities and allergies, avoidance is a much weaker tool than observation.

Where to Go Next

Learning to read by function is the shift. Applying it to your own routine, product by product, is a system.

I am building a set of guides that do exactly that, for curly, straight, and gray hair. They are not out yet, but they are coming.

Let your hair be your guide.

Verna

References

1. Science-y Hair Blog (Wendy M.S.). Silicone Ingredient Solubility List, updated April 2022; Detergents Which Remove Silicones, 2016. Licensed CC BY-NC-ND 4.0. Cited and linked, not reproduced.

2. Kiken, D. A., & Cohen, D. E. (2002). Contact dermatitis to botanical extracts. American Journal of Contact Dermatitis, 13(3), 148-152.

3. Corazza, M., Borghi, A., Lauriola, M. M., & Virgili, A. (2009). Use of topical herbal remedies and cosmetics: a questionnaire-based investigation in dermatology out-patients. Journal of the European Academy of Dermatology and Venereology, 23(11), 1298-1303.

4. de Groot, A. C., & Schmidt, E. (2016). Tea tree oil: contact allergy and chemical composition. Contact Dermatitis, 75(3), 129-143.

5. Goodier, M. C., Zhang, A. J., Nikle, A. B., Hylwa, S. A., Goldfarb, N., & Warshaw, E. M. (2019). Use of essential oils: a general population survey. Contact Dermatitis, 80(6), 391-393.

6. Bozzi, A., Perrin, C., Austin, S., & Arce Vera, F. (2007). Quality and authenticity of commercial aloe vera gel powders. Food Chemistry, 103(1), 22-30.

7. Scientific Committee on Consumer Safety (2012). The SCCS notes of guidance for the testing of cosmetic substances and their safety evaluation, 8th revision.

8. Robbins, C. R. (2012). Chemical and Physical Behavior of Human Hair (5th ed.). Springer.