Rated 5 — the maximum on the comedogenic scale
14 ingredients, listed alphabetically rather than ranked against each other, because a shared score of 5 does not order them. Each links to its full page with sources.
Worst Pore-Clogging Ingredients
The worst pore-clogging ingredients are the ones rated 4 or 5 on the 0–5 comedogenic scale. 39 of the 216 ingredients in this database sit in that band, and 14 of them score the maximum 5 — led by the synthetic emollient esters isopropyl myristate, isopropyl isostearate, myristyl myristate, isocetyl stearate and octyl stearate.
A high rating means the ingredient reliably clogged pores when tested on its own at high concentration. It does not mean a product containing it will break you out — position on the label and concentration decide that. Treat this as the list to check the first five ingredients of a product against, not a list of things to throw away.
14 of 216 ingredients (6.5%) carry the maximum rating of 5 — and only 1 of them is a plant oil. 5 are synthetic emollient esters; the remaining 8 are two emulsifiers, two algae extracts, a seaweed thickener, a surfactant, a butter and table salt. The thing most often blamed for clogged pores is the thing least represented at the top of our scale. Counted from 190 published ratings in our own dataset on 2026-09-14; disputed ratings are counted at their midpoint.
Check your own label
The checker below is loaded with a rich-cream label carrying four ingredients from this page. Paste your own list over it to see what is flagged, where it sits, and what to swap in. It runs entirely in your browser.
🔒 Your list never leaves your browser
4 pore-clogging ingredients found
Recognized 9 of 10 listed ingredients · 1 not in our database (often water, fragrance, extracts or actives that don't clog).
Your report: 9 ingredients checked, 4 pore-clogging
Keep the list you just checked — every ingredient with its rating and gentler swaps, written to a text file in your browser. No email needed, nothing uploaded.
We couldn't rate 1 ingredient on your list yet
We add ingredients to the database as published sources come in. Leave your email and we'll tell you once these have ratings — that's the only reason we'd write.
- Isopropyl MyristateEster / emollientHigh risk · 5/5
A lightweight synthetic ester used to give products a fast, non-greasy slip. One of the most reliably pore-clogging cosmetic ingredients on the Fulton scale, scoring the maximum 5.
Gentler swaps: Caprylic/Capric Triglyceride, Squalane
- Cocoa ButterButter · disputedHigh risk · 4–5/5
A thick, occlusive butter. Most lists rate it 4 while some place it at 5; either way it is high-risk and best kept off acne-prone areas.
Gentler swaps: Squalane, Mango Butter
- Coconut OilOilHigh risk · 4/5
Rich in lauric and myristic acids. Deeply moisturising but a classic 4/5 pore-clogger, and one of the most common causes of breakouts when used on the face.
Gentler swaps: Squalane, Hemp Seed Oil, Sunflower Oil
- Laureth-4EmulsifierHigh risk · 5/5
A low-ethoxylate laureth emulsifier that scores high on both comedogenicity (5) and irritancy (4).
Gentler swaps: Glyceryl Stearate, Cetearyl Alcohol
- GlycerinHumectantLow risk · 0/5
A universal humectant rated 0/5. Non-comedogenic and fungal-acne safe, suitable for all skin types.
- Cetearyl AlcoholFatty alcoholLow risk · 2/5
A blend of cetyl and stearyl alcohols used as an emollient thickener. Rated 2/5; fatty alcohols are considered fungal-acne safe.
- DimethiconeSilicone · disputedLow risk · 1/5
A breathable silicone that smooths and blurs. Rated 1/5 and fungal-acne safe; occasionally blamed for congestion when layered heavily, but the ingredient itself is low-risk.
- Tocopherol (Vitamin E)AntioxidantLow risk · 2/5
Vitamin E, a common antioxidant rated 2/5. Widely used at low levels where its clogging impact is minimal.
- PhenoxyethanolPreservativeLow risk · 0/5
A broad-spectrum preservative rated 0/5 for clogging, mildly irritating for a few.
Marine algae extracts score high (often 4-5) on both comedogenicity and irritancy in classic testing, though the category is broad and results vary by species.
Gentler swaps: Hyaluronic Acid (0/5), Niacinamide (0/5)
A red-algae-derived gelling agent (Irish moss) rated 5/5 on the classic scale, though at the tiny use levels in most formulas its practical impact is debated.
Gentler swaps: Squalane (1/5), Niacinamide (0/5)
A thick, occlusive butter. Most lists rate it 4 while some place it at 5; either way it is high-risk and best kept off acne-prone areas.
Gentler swaps: Squalane (1/5), Mango Butter (2/5)
A heavy emollient ester that leaves a rich, cushioned feel. Non-irritating but a maximum 5/5 on the comedogenic scale.
Gentler swaps: Caprylic/Capric Triglyceride (1/5), Squalane (1/5)
A branched isostearic ester in the same family as isopropyl myristate. Non-irritating but rated the maximum 5 for pore-clogging potential.
Gentler swaps: Caprylic/Capric Triglyceride (1/5), Squalane (1/5)
A lightweight synthetic ester used to give products a fast, non-greasy slip. One of the most reliably pore-clogging cosmetic ingredients on the Fulton scale, scoring the maximum 5.
Gentler swaps: Caprylic/Capric Triglyceride (1/5), Squalane (1/5)
A low-ethoxylate laureth emulsifier that scores high on both comedogenicity (5) and irritancy (4).
Gentler swaps: Glyceryl Stearate (1/5), Cetearyl Alcohol (2/5)
A waxy emollient ester used to thicken and give a velvety finish. Sits at the top of the comedogenic scale at 5/5.
Gentler swaps: Caprylic/Capric Triglyceride (1/5), Squalane (1/5)
Also called ethylhexyl stearate. Unusually, it scores the maximum on both the comedogenic and irritancy axes, making it a double flag for sensitive, acne-prone skin.
Gentler swaps: Caprylic/Capric Triglyceride (1/5), Squalane (1/5)
A low-ethoxylate oleth emulsifier rated as high as 5 on classic lists, though some newer references place it around 3.
Gentler swaps: Glyceryl Stearate (1/5), Cetearyl Alcohol (2/5)
A red seaweed extract rated 5/5 for comedogenicity in classic lists.
Gentler swaps: Hyaluronic Acid (0/5), Niacinamide (0/5)
Common salt scores a surprising 5 on the classic comedogenic assay, likely a mechanical effect; in most rinse-off or low-salt formulas the practical risk is small.
Gentler swaps: Squalane (1/5), Niacinamide (0/5)
A harsh cleansing surfactant rated 5/5. Mostly a concern in leave-on products; in rinse-off cleansers its contact time is short.
Gentler swaps: Squalane (1/5), Niacinamide (0/5)
One of the most comedogenic natural oils at 5/5, despite being rich in vitamin E. Best avoided on the face if you are acne-prone.
Gentler swaps: Squalane (1/5), Hemp Seed Oil (0/5), Sunflower Oil (0/5)
Rated 4 — high risk on acne-prone skin
A further 25 ingredients rate 4. This band is where the lanolin derivatives and the well-known plant oils show up, including the one most people have actually heard about.
A heavy, occlusive lanolin derivative used in rich balms. Rated 4/5 for pore-clogging.
Gentler swaps: Squalane (1/5), Petrolatum (0/5)
Rated 4/5 at full strength (some sources say 4-5), but this drops sharply at the low concentrations used in real formulas, per INCIDecoder, so treat the flag with context.
Gentler swaps: Squalane (1/5), Petrolatum (0/5)
A brown-algae thickener rated 4/5 on both comedogenic and irritancy axes in classic testing.
Gentler swaps: Squalane (1/5), Niacinamide (0/5)
A brown seaweed extract grouped with the high-rated marine ingredients on pore-clogging lists.
Gentler swaps: Hyaluronic Acid (0/5), Niacinamide (0/5)
A carrier (not the essential) oil often placed around 4 on comedogenic charts. Data is thin, so treat as high-moderate.
Gentler swaps: Squalane (1/5), Hemp Seed Oil (0/5), Sunflower Oil (0/5)
The red seaweed behind carrageenan, named on pore-clogging lists in the high range.
Gentler swaps: Hyaluronic Acid (0/5), Niacinamide (0/5)
A traditional psoriasis and dandruff active repeatedly named as pore-clogging in the high range.
Gentler swaps: Squalane (1/5), Niacinamide (0/5)
A whipped coconut fat with the same fatty-acid profile as coconut oil, rated 4/5.
Gentler swaps: Squalane (1/5), Mango Butter (2/5)
Rich in lauric and myristic acids. Deeply moisturising but a classic 4/5 pore-clogger, and one of the most common causes of breakouts when used on the face.
Gentler swaps: Squalane (1/5), Hemp Seed Oil (0/5), Sunflower Oil (0/5)
The modern INCI name for octyl palmitate, a dry-touch emollient rated 4/5.
Gentler swaps: Caprylic/Capric Triglyceride (1/5), Squalane (1/5)
A fragile omega-3 oil that oxidises quickly; commonly rated around 4 and generally kept out of leave-on facial products.
Gentler swaps: Squalane (1/5), Hemp Seed Oil (0/5), Sunflower Oil (0/5)
A lanolin ester frequently named on pore-clogging lists in the high range.
Gentler swaps: Squalane (1/5), Petrolatum (0/5)
A palmitic-acid ester prized as a cheap emollient and texture enhancer. Rates 4/5 for comedogenicity, so it is a common flag in cleansers and lotions marketed to oily skin.
Gentler swaps: Caprylic/Capric Triglyceride (1/5), Squalane (1/5)
Kelp-family (Laminaria) extracts are repeatedly named as pore-clogging in the high range on comedogenic lists.
Gentler swaps: Hyaluronic Acid (0/5), Niacinamide (0/5)
A C12 saturated fatty acid abundant in coconut and palm-kernel oils. Rated 4/5 and a prime fatty-acid fuel for malassezia.
A lactic-acid ester of myristyl alcohol used as a light emollient. Rated 4/5 for comedogenicity.
Gentler swaps: Caprylic/Capric Triglyceride (1/5), Squalane (1/5)
Also labelled ethylhexyl palmitate, a silky dry-touch emollient common in sunscreens and primers. Rated 4/5 for pore-clogging.
Gentler swaps: Caprylic/Capric Triglyceride (1/5), Squalane (1/5)
An unsaturated fatty alcohol derived from oleic acid that is often placed high on comedogenic lists.
Gentler swaps: Squalane (1/5), Niacinamide (0/5)
A saturated tropical oil high in palmitic acid, frequently flagged around 4 on pore-clogging lists.
Gentler swaps: Squalane (1/5), Hemp Seed Oil (0/5), Sunflower Oil (0/5)
An ethoxylated lanolin derivative that scores high on both comedogenicity (4) and irritancy (3).
Gentler swaps: Squalane (1/5), Petrolatum (0/5)
A marine plankton extract grouped with algae on pore-clogging lists in the high range.
Gentler swaps: Hyaluronic Acid (0/5), Niacinamide (0/5)
A slip-agent ester derived from myristyl alcohol, often placed high on pore-clogging lists.
Gentler swaps: Caprylic/Capric Triglyceride (1/5), Squalane (1/5)
A stearate ester used to emulsify and thicken. Rated 4/5 for comedogenicity despite being non-irritating.
Gentler swaps: Glyceryl Stearate (1/5), Cetearyl Alcohol (2/5)
A blue-green algae named on pore-clogging lists in the high range; data is limited and formula-dependent.
Gentler swaps: Hyaluronic Acid (0/5), Niacinamide (0/5)
A cushiony ester used in colour cosmetics and creams for a smooth payoff. Rated 4/5 for comedogenicity.
Gentler swaps: Caprylic/Capric Triglyceride (1/5), Squalane (1/5)
The oil myth, in our own numbers
"Oils clog pores" is the most repeated claim in this niche and it does not survive contact with the dataset. Of the 14 ingredients at the top of the scale, 1 is a plant oil and 5 are synthetic esters invented specifically to feel lighter than oil. Coconut oil, which is the single ingredient most often named in breakout stories, rates 4 rather than 5 — and plenty of plant oils rate 0. The full picture is on the oils ranked by comedogenic rating page, where more than half the rated oils come in at 0–2.
How to use this list without over-correcting
- Read the first five or six ingredients. Those are present in meaningful amounts; a 5 sitting second-to-last on a label usually is not.
- Check the whole label at once with the pore-clogging ingredient checker rather than scanning by eye — it sorts everything worst-first and suggests swaps.
- Trust your own skin over the number. These ratings come from single-ingredient testing and plenty of people use 4s and 5s with no trouble.
- If your breakouts are small, uniform and itchy, comedogenic ratings may be the wrong tool entirely — check the fungal acne safe ingredients instead.
- Want it on paper for the shop? The printable cheat sheet condenses the avoid/watch/safe tiers onto one page.
Coming back to this list later?
This page is free and public — no email needed to read it, and nothing here is gated. But which ingredients sit at the top of the scale changes as published sources come in. Leave your address and we'll write once when it does; that's the only reason we'd write.
Questions people ask
What is the worst pore-clogging ingredient?
14 ingredients share the maximum score of 5 on the 0–5 comedogenic scale, so there is no single worst one. The group is led by the synthetic emollient esters — isopropyl myristate, isopropyl isostearate, myristyl myristate, isocetyl stearate and octyl stearate — which are used to give products a fast, non-greasy slip and are the most reliably comedogenic ingredients in the dataset.
Do oils clog pores the most?
No, and our own data contradicts the popular version of this. Of the 14 ingredients rated 5, only 1 is a plant oil (wheat germ oil), while 5 are synthetic esters. Most plant oils in the database rate 0–3. The reputation oils have for breaking people out comes mainly from coconut oil, which does rate 4.
Should I avoid every ingredient on this list?
Not mechanically. A comedogenic rating measures a single ingredient tested at high concentration, so where it sits on a label matters — an ingredient rated 5 in the last three positions is usually present in trace amounts. The list is most useful for congestion-prone skin when one of these appears in the first five or six ingredients.
What can I use instead?
Each entry below carries the gentler swaps our database suggests for its category. In practice the substitutions that come up most often are squalane for a heavy plant oil or butter, caprylic/capric triglyceride for an emollient ester, and glycerin or hyaluronic acid where the job is hydration rather than slip.
Why do some ratings show a range?
Because credible published sources genuinely disagree about them. Cocoa butter is scored 4 by some and 5 by others, so we publish the span rather than forcing a number. In the counts on this page a disputed ingredient is placed at the midpoint of its range, never at whichever endpoint would make the statistic look starker.
Ratings originate largely from the Fulton rabbit-ear comedogenicity assay and its widely republished derivatives. They test single ingredients at high concentration and do not account for the finished formula, where concentration and position on the INCI list change real-world behaviour. Treat a rating as a flag to consider, not a verdict. Informational only, not medical advice.
Every rating in context on the full pore-clogging ingredients list, or start checking with the free pore clog checker.