Are Silicones Bad for Low Porosity Hair?
Silicones are not automatically bad for low porosity hair. How dimethicone, amodimethicone, PEG and volatile types differ, and how to wash off build-up.
No. Silicones are not bad for low porosity hair as a group. They mainly coat the hair surface, so whether one weighs your hair down depends on its type, how much you apply and where, your strand thickness, and whether your shampoo removes it. Judge by how your hair feels after a normal wash.
What does low porosity hair actually mean?
Porosity is how readily hair takes up and releases water. Amber Evans’s 2020 overview for the New York Society of Cosmetic Chemists (NYSCC) ties it to cuticle integrity, describes low porosity hair as slow to wet and to dry, and notes porosity can vary on one head. Home float and spray tests, it says, “have limitations but can potentially give a general idea under controlled conditions.” Residue, water temperature, hair density and humidity can also skew the result.
Strand thickness is a separate trait, not a porosity measure. Fine hair can have porous bleached ends, and coarse hair can be low porosity. Thickness still matters here, because the same film shows more on thin, light strands.
Which silicones are most likely to weigh hair down?
Non-volatile silicones in leave-on products are the usual suspects, because they stay on the hair until washing removes them, and how completely that happens depends on the shampoo formula and how much has accumulated. Gavazzoni Dias’s 2015 hair cosmetics review notes that silicones differ in solubility and deposition and that dimethicone is hydrophobic, so water alone does not lift it. Amino silicones such as amodimethicone are cationic, yet that does not automatically make them more substantive; molecule size and the formula’s overall charge decide.
| Family | INCI names you will see | How to use it on low porosity or fine hair |
|---|---|---|
| Non-volatile linear | Dimethicone, Dimethiconol | Fine in rinse-off conditioner; in leave-ins, a small amount on the lengths. Removal depends on your shampoo, so check how lengths feel after the next wash |
| Amino-modified | Amodimethicone, Bis-Aminopropyl Dimethicone | Start with a small amount and judge by how lengths feel after your next normal wash |
| Volatile | Cyclopentasiloxane | Read the rest of the list; non-volatile silicones in the same product stay behind |
| PEG/PPG-modified | PEG-12 Dimethicone, PEG/PPG-18/18 Dimethicone | Do not choose by the prefix; weigh the whole formula, how much you use and how hair feels after washing |
PEG/PPG silicones. The Cosmetic Ingredient Review (CIR) 2015 report on these copolymers says their properties depend mainly on the silicone part and that the PEG/PPG numbers describe only the added chain. PEG segments tend to be water-soluble, but the prefix does not settle how a finished product rinses.
Cyclopentasiloxane. Dow’s technical data sheet for its SH 245 fluid describes cyclopentasiloxane as a volatile carrier that evaporates under ordinary conditions; it does not mix with water. Evaporating and dissolving are different things. In a shine serum that lists Cyclopentasiloxane first and then Dimethicone and Dimethiconol, the carrier leaves and the other two stay on the hair.
List position. Where a silicone sits on an ingredient list is a weak guide to how much reaches your hair. The list gives no percentages, and a few pumps of a light leave-in every day can add up to more film than a richer conditioner rinsed out well.
Safety. The CIR Expert Panel concluded that dimethicone, amodimethicone and related silicones (2003) and the PEG/PPG family (2015) are safe as used in the formulations it assessed. Those findings address safety, not feel, build-up or individual allergy.
Can sulfate-free shampoo remove silicone build-up?
Often, yes. “Sulfate-free” tells you which surfactants were left out; it is not a measured cleansing score. Many sulfate-free shampoos use other anionic surfactants such as Sodium C14-16 Olefin Sulfonate, and the total surfactant level and any added conditioning agents shape what is left behind. No single INCI name proves a shampoo will remove a given silicone, so judge by outcome: if your lengths feel clean and move freely after a normal wash, it is keeping up with what you apply.
Lab work on shampoo formulas shows why outcome beats labels:
- Polymers changed accumulation. In a 2001 Journal of Cosmetic Science study, Gruber and colleagues used X-ray fluorescence on virgin hair tresses. Dimethicone built up over repeated washes with a polymer-free model shampoo; adding polyquaternium-10 reduced that build-up, while a higher molecular weight polymer increased the amount deposited.
- Some 2-in-1s clear the last layer. A 1994 Skin Pharmacology paper by Rushton and colleagues describes 2-in-1 shampoos that release suspended dimethicone on rinsing; in the formulations described, later washes removed the earlier layer.
Neither “every 2-in-1 builds up” nor “every conditioning polymer is a problem” survives this lab evidence.
Is it silicone build-up or something else?
A coated feel is a symptom, not an ingredient identification. Silicone film is one possibility; so are heavy oils and butters, conditioning polymers, styling resins, hard-water minerals and soap residue. Heaviness that tracks where you apply product, builds over several days of reapplying and eases after a thorough normal shampoo points toward leave-on product. A waxy feel straight after washing, or one a clarifying wash does not shift, points more toward water or soap residue; our guide to why hair feels waxy after washing walks through those causes. If you have swapped silicones for oils, is hair oiling scientifically proven? explains which oils mostly sit on the surface.
What should you do? Match the fix to your hair
| If your hair… | Likely factor | Try first |
|---|---|---|
| Feels heavy within a day of washing | Leave-in amount or placement | Use less, apply from mid-length down, and skip reapplying on the next day |
| Is fine and untreated and goes limp after conditioner | Conditioner on the roots or not rinsed well | Condition the lengths only and rinse thoroughly; try a lighter rinse-off |
| Has bleached or heat-styled ends and untreated roots | Different porosity along the strand | Put richer silicone products on the ends; keep roots light |
| Gets heavier over several co-washes or very mild washes | Deposit outpacing removal | Add a regular shampoo wash as directed; clarify once if lengths still feel coated |
| Still feels coated after a clarifying wash | Possibly minerals, soap residue, oils or polymers | Check water hardness and soap-based products before blaming silicone |
| Is blow-dried or flat-ironed most days | Heat and friction | Use a product sold as a heat protectant, as directed |
| Comes with an itchy, stinging or flaky scalp | Scalp irritation, not just residue | Do not scrub harder or wash more; pause the suspected product |
How often should you clarify low porosity hair?
As often as your hair needs and the product directions allow, with no fixed weekly schedule. Start with your regular shampoo used as directed, working it through the lengths where product sits. A second lather is an option after heavy product use, not a rule for every wash. Reach for a clarifying shampoo when a normal wash no longer leaves lengths feeling clean, and space it out if your scalp feels tight or your ends feel rough afterward. If scalp itching or irritation continues after you stop a suspected product, see a board-certified dermatologist rather than washing more often.
When do silicones help low porosity hair?
Low porosity roots still get brushed, heat-styled and rubbed against pillows, which is how ends become more porous over time. The Dias review also describes conditioners cutting friction in lab fiber work and leave-ons making virgin straight hair look oily, the trade-off fine, untreated hair notices first.
For heat, choose a finished product made and labeled as a heat protectant and follow its directions; a silicone on the ingredient list does not tell you what temperature it handles. For winter flyaways, see why is my hair so staticky?
What the evidence says
| Claim | Best evidence | Study type, size, duration | Strength |
|---|---|---|---|
| Home float and spray tests give only a rough guide | NYSCC overview, Evans 2020 | Professional-society overview | Guidance |
| Dimethicone built up from a polymer-free model shampoo; polyquaternium-10 reduced it | Gruber et al. 2001, J Cosmet Sci | X-ray fluorescence on virgin hair tresses, model shampoos | Lab-only |
| Some 2-in-1 formulas remove earlier dimethicone layers | Rushton et al. 1994, Skin Pharmacol | Technical description of 2-in-1 shampoo systems | Lab-only |
| A PEG/PPG name does not fix the whole molecule’s solubility | CIR 2015 final report | Expert-panel chemistry and safety assessment | Guidance |
| Cyclopentasiloxane evaporates but does not mix with water | Dow SH 245 technical data sheet, 2020 | Manufacturer physical-property data | Lab-only |
| Amino silicones are not automatically more substantive | Gavazzoni Dias 2015 review | Narrative review, mainly lab-based | Lab-only |
| Dimethicone, amodimethicone and related silicones are safe as used | CIR 2003 final report | Expert-panel safety assessment | Guidance |
Related reading
- Why does my hair feel waxy after washing? for hard water, soap scum and clarifying versus chelating shampoos.
- Is hair oiling scientifically proven? for which oils penetrate and which mostly coat.
- Why is my hair so staticky? for how conditioners and silicones calm static.
Sources and research notes
A New York Society of Cosmetic Chemists porosity overview, lab studies of silicone deposition from shampoo, a 2015 review of hair cosmetics, Cosmetic Ingredient Review safety assessments of dimethicone, amodimethicone and PEG/PPG-modified silicones, and Dow's cyclopentasiloxane technical data sheet, checked on the date shown.
Source record date: 2026-10-13. Prices and availability are as of that date.
- New York Society of Cosmetic Chemists: An overview on hair porosity (Evans, November 11, 2020)
- Gruber JV et al. X-ray fluorescence study of cationic polymers and silicone oil deposition from shampoo. J Cosmet Sci, 2001
- Rushton H et al. 2-in-1 shampoo technology. Skin Pharmacol, 1994
- Gavazzoni Dias MF. Hair cosmetics: an overview. Int J Trichology, 2015
- Cosmetic Ingredient Review: Safety assessment of polyoxyalkylene siloxane copolymers (PEG/PPG dimethicones, 111 ingredients), final report January 2015
- Cosmetic Ingredient Review: Final report on the safety assessment of dimethicone, amodimethicone and related silicones. Int J Toxicol, 2003
- Dow: DOWSIL SH 245 Fluid (cyclopentasiloxane) technical data sheet, 2020
Frequently asked questions
Should low porosity hair avoid all silicones?
No. Choose by the whole formula and by how your hair feels after a normal wash. Fine, untreated hair usually handles a small amount on the lengths better than a heavy leave-in applied from the roots.
Is dimethicone or amodimethicone better for low porosity hair?
Neither wins by name. Both can work in a rinse-off conditioner; keep the one that still leaves your lengths feeling clean after your next regular shampoo, and use less of either in leave-ins.
Are PEG silicones water soluble?
Some are, but the prefix alone does not prove a product rinses out easily. Judge by how your hair feels after washing.
Can sulfate-free shampoo remove silicone buildup?
Many can. Sulfate-free only says which surfactants were left out, so judge by results: if your lengths feel clean and light after a normal wash, the shampoo is keeping up with what you apply.
Is the float test an accurate way to check hair porosity?
Treat it as a rough hint, not a diagnosis. Your bleach, relaxer and heat-styling history is usually a steadier clue to which lengths are more porous.
How often should I clarify low porosity hair?
Only when a regular wash stops leaving your lengths clean, following the product directions. There is no universal weekly schedule, and an irritated scalp needs gentler care, not more washing.