Comedogenic ratings — the 0 to 5 scores you see in online ingredient lists — estimate how likely an ingredient is to clog pores. Most come from rabbit-ear tests from the 1970s and 1980s, which tested ingredients alone, often at high concentrations.
They can flag ingredients worth watching, but they don't reliably predict how a finished product will behave on your skin. Concentration, the full formula and your own skin matter more. This guide explains what the ratings can and can't tell you, and the C.L.O.G. Check — Context, Look for product testing, Observe your skin, Gauge other causes.
This article is for educational purposes only. It does not constitute medical advice. Persistent, painful or scarring acne should be assessed by a dermatologist. Last reviewed: 27 October 2026.
Comedogenic ratings are 0–5 scores estimating how likely an ingredient is to clog pores, based mostly on rabbit-ear tests from the 1970s and 1980s. They are only a rough guide: the tests often used undiluted ingredients, rabbit skin is more sensitive than human facial skin, and results varied between labs. Whether a product clogs pores depends on the ingredient's concentration, the full formula and the individual. Ratings can help acne-prone people spot ingredients worth watching, but finished-product testing and how your own skin responds over several weeks are more reliable. "Non-comedogenic" is not a regulated term in most markets.
- Ratings are a rough starting point, not a verdict.
- Concentration and formula change everything.
- Your own skin's response is the best test.
- Breakouts often have other causes — hormones, friction, sweat.
- What are comedogenic ratings?
- Where do comedogenic ratings come from?
- Why are comedogenic ratings limited?
- Ingredient ratings vs finished-product testing
- Comedogenic vs acnegenic vs irritating
- What does the research show?
- The C.L.O.G. Check
- Step-by-step: choosing products for acne-prone skin
- Clogged pores in Indian conditions
- Illustrative case study
- Common myths
- Frequently asked questions
- Key takeaways
If you have acne-prone skin, you've probably checked an ingredient list against an online chart of comedogenic ratings. But are comedogenic ratings a useful guide or an outdated myth? The honest answer is that they're a blunt tool — helpful for spotting red flags, unreliable as a final judgement.
A commonly described pattern: someone screens every product against a comedogenic chart, throws out anything containing a high-rated ingredient, yet keeps getting breakouts along the jawline.
The cause turns out to be hormonal acne and phone friction, not a single ingredient. This scenario is illustrative and does not describe a specific individual.
What Are Comedogenic Ratings?
- Comedone: a clogged pore — a blackhead (open) or whitehead (closed).
- Comedogenic: likely to cause comedones.
- The scale: 0 = unlikely to clog; 1–2 = low; 3 = moderate; 4–5 = high.
- Where you see them: ingredient databases, social media charts and some product marketing.
- What they rate: individual raw ingredients — not finished products.
In simple terms: a comedogenic rating is like a spice rating for a single chilli. It tells you something, but not how spicy the finished curry will be — that depends on how much is used and what else is in the pot.
Where Do Comedogenic Ratings Come From?
- 1970s: researchers noted "acne cosmetica" — breakouts linked to cosmetics.
- Rabbit-ear assay: ingredients were applied to rabbit ears, which form comedones easily, and graded under a microscope.
- Human back test: later tests applied ingredients to the upper back of volunteers under occlusion.
- Popular lists: many online charts trace back to a 1989 ingredient compilation.
- Re-evaluation: later research questioned how well rabbit results predict human facial skin.
Why Are Comedogenic Ratings Limited?
- Concentration: ingredients were often tested undiluted, far above typical product levels.
- Formula context: other ingredients can change how a substance behaves on skin.
- Species difference: rabbit ears are more prone to comedones than human facial skin.
- Inconsistent results: the same ingredient can have different ratings in different sources.
- Raw material variation: purity and grade of an ingredient can differ between suppliers.
- Individual skin: oiliness, genetics and hormones vary between people.
Neither entirely. Ratings are a rough early-warning tool for very acne-prone people, but they're outdated as a decision rule. Finished-product testing and your own skin's response over several weeks tell you far more.
Ingredient Ratings vs Finished-Product Testing
| Method | What It Tests | Strengths | Limits |
|---|---|---|---|
| Rabbit-ear assay | Single ingredients, often undiluted | Sensitive screen | Over-predicts for humans; older method |
| Human back test | Ingredients or products under occlusion | Uses human skin | Back skin differs from the face |
| Finished-product use testing | The actual product on faces over weeks | Most relevant to real use | Methods and quality vary |
| Online rating charts | Compiled ingredient scores | Quick, accessible | No context; sources often unclear |
| Personal use observation | One product on your skin for 4–6 weeks | Personal and practical | Not a validated comedogenicity test; slow; other factors can confuse results |
A standard patch test mainly checks for irritation or allergic reactions; it doesn't show whether a product will clog pores.
Comedogenic vs Acnegenic vs Irritating
| Term | Meaning | What You Might See |
|---|---|---|
| Comedogenic | Linked to clogged pores | Blackheads, whiteheads, bumpy texture |
| Acnegenic | A less consistently used term for products linked to inflamed, acne-like bumps | Red bumps — but their timing alone doesn't prove a product caused acne |
| Irritation (look-alike) | Barrier disruption | Stinging, redness, rough patches that can resemble breakouts |
| "Fungal acne" (look-alike) | A colloquial term for Malassezia folliculitis — a different condition from acne vulgaris | Small, uniform, itchy bumps; needs a different approach |
These are possible look-alikes, not diagnoses — a dermatologist can confirm what's causing bumps.
See how acne forms and which actives help.
What Does the Research Show?
| Source | Type | Finding |
|---|---|---|
| Kligman & Mills — Acne cosmetica (1972) | Clinical observation | Described acne linked to cosmetic use |
| Mills & Kligman — Human comedogenicity model (1982) | Human test method | Developed a human back test for comedogenic substances |
| Fulton — Comedogenicity of ingredients (1989) | Ingredient compilation | Rated many ingredients; source of many online charts |
| Draelos & DiNardo — Re-evaluating comedogenicity (2006) | Review and study | Rabbit-ear results didn't reliably predict human outcomes; finished products should be tested |
| Nguyen et al. — Comedogenicity in rabbits (2007) | Review | Highlighted variability and limits of the rabbit model |
| Zaenglein et al. — Acne guidelines (2016) | Clinical guideline | Recommends non-comedogenic products as part of acne care |
Much of the original data is decades old, and few modern studies test individual ingredients at real-world concentrations on facial skin.
"An ingredient's rating tells you its reputation. Your skin over six weeks tells you the truth."
The C.L.O.G. Check
To judge whether a product may clog your pores, the Boldpurity Science Team uses the C.L.O.G. Check — an original educational framework, not a clinical test:
- C — Context: where does the ingredient sit on the list, and what type of product is it — a rinse-off cleanser or a leave-on cream? List position hints at concentration but can't confirm the exact amount or predict comedogenicity on its own.
- L — Look for product testing: has the finished product been tested on human skin, and are details shared?
- O — Observe your skin: introduce one product at a time and watch for new comedones over four to six weeks.
- G — Gauge other causes: hormones, friction, sweat, hair products, picking and diet-related triggers.
The C.L.O.G. Check is an original Boldpurity Science Team teaching model. It is not a clinical test.
Step-by-Step: Choosing Products for Acne-Prone Skin
These eight steps put the four C.L.O.G. principles into practice.
- Read the full ingredient list, not just the front-of-pack claim.
- Note where any high-rated ingredient appears — near the top generally means a higher concentration, though order alone can't confirm the exact amount or predict comedogenicity.
- Consider the product type — rinse-off products are generally less of a concern than heavy leave-on creams.
- Look for products tested on human skin, and check what the testing involved.
- Introduce one new product at a time and keep the rest of your routine unchanged — this is personal observation, not a formal comedogenicity test.
- Track your skin for four to six weeks with photos in consistent light.
- Look beyond products — pillowcases, phone screens, helmets, hair oils and sweat.
- See a dermatologist for persistent, painful, cystic or scarring acne.
See skin texture and pores and niacinamide for oil control.
Clogged Pores in Indian Conditions
- Heat and humidity: sweat and oil can mix with heavy products — lighter textures often suit humid months.
- Hair oiling: oils can migrate to the forehead and hairline; wash or cover hair at night.
- Coconut oil on the face: often rated highly in traditional comedogenicity lists, though ratings don't predict every individual's response — acne-prone readers may choose to be cautious and observe their own skin.
- Helmets and masks: friction and trapped sweat can trigger breakouts. See maskne and friction-related breakouts.
- Thick sunscreens: try lightweight gels or fluids rather than skipping sun protection.
- Monsoon bumps: small itchy bumps may be fungal acne, not clogged pores. See monsoon breakouts and humidity.
Illustrative Case Study
The example below is hypothetical and does not report measured results.
Profile: Age 22; oily, acne-prone skin; closed comedones along the hairline; oils hair twice a week overnight; uses a rich night cream.
C.L.O.G. plan: Switches to a lighter gel moisturiser; covers hair with a cotton scarf on oiling nights and washes it off sooner; changes pillowcases often; introduces one new product at a time over six weeks.
Hypothetical outcome (not a measured result): In this scenario, hairline bumps reduce as hair oil contact decreases. Lesson: look beyond the ingredient list.
This guide was researched and reviewed by the Boldpurity Science Team using the original acne cosmetica and comedogenicity research, the 1989 ingredient compilation, later re-evaluations of the rabbit-ear model and current acne treatment guidelines. The case study is hypothetical. We update articles when significant new evidence is published.
Common Myths About Comedogenic Ratings
The term isn't regulated in most markets, and testing methods vary. Individual skin can still react.
Fact: It's a helpful claim, not a guarantee.
Oils vary widely; some are lightweight and less likely to clog, others are heavier. Formula and skin type matter.
Fact: Judge the product, not the category.
Frequently Asked Questions About Comedogenic Ratings
Comedogenic Ratings: Key Takeaways
Comedogenic ratings are a rough, dated guide — useful for spotting ingredients to investigate, unreliable as the final word on how a finished product will behave on your skin. Use the C.L.O.G. Check — Context, Look for product testing, Observe your skin, Gauge other causes — and let your own skin's response guide your choices.
A water-light bubble toner serum (100 ml) designed for dryness and barrier support — a lightweight hydrating layer for routines where heavy creams feel too rich. Check the full ingredient list on the product page.
Explore AquaBlur™
An encapsulated salmon PDRN serum (30 ml) with niacinamide, formulated to help support hydration and the look of signs of ageing. Introduce it on its own and observe your skin for several weeks.
Explore SkinReset™
A spicule serum formulated to help refine the look of skin texture. Not for active, inflamed breakouts, irritated or broken skin; follow the approved directions on the product page and avoid combining it with other irritating treatments. Tingling does not indicate effectiveness.
Explore CellMorph™- Kligman, A.M., & Mills, O.H. (1972). "Acne cosmetica." Archives of Dermatology, 106(6), 843–850. PubMed
- Mills, O.H., & Kligman, A.M. (1982). A human model for assessing comedogenic substances. Archives of Dermatology, 118(11), 903–905. PubMed
- Fulton, J.E. (1989). Comedogenicity and irritancy of commonly used ingredients in skin care products. Journal of the Society of Cosmetic Chemists, 40, 321–333. Google Scholar
- Draelos, Z.D., & DiNardo, J.C. (2006). A re-evaluation of the comedogenicity concept. Journal of the American Academy of Dermatology, 54(3), 507–512. PubMed
- Nguyen, S.H., Dang, T.P., & Maibach, H.I. (2007). Comedogenicity in rabbit: some cosmetic ingredients/vehicles. Cutaneous and Ocular Toxicology, 26(4), 287–292. PubMed
- Zaenglein, A.L., Pathy, A.L., Schlosser, B.J., et al. (2016). Guidelines of care for the management of acne vulgaris. Journal of the American Academy of Dermatology, 74(5), 945–973. PubMed
- Draelos, Z.D. (2018). The science behind skin care: moisturizers. Journal of Cosmetic Dermatology, 17(2), 138–144. PubMed
- Government of India, Ministry of Health and Family Welfare. The Drugs and Cosmetics Act, 1940 and the Cosmetics Rules, 2020. CDSCO
Links open the official source, a PubMed search or a Google Scholar search for the cited paper.
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