Does Isononyl Isononanoate clog pores?

What is Isononyl Isononanoate?

Isononyl Isononanoate is an emollient ester that gives products a smooth, silky feel. You'll most often see it in foundations, primers, sunscreens, lotions and anything with a light, silky slip.

Fungal-acne (Malassezia) safe? No — this is a common Malassezia (fungal acne) trigger, so avoid it if you have fungal acne. Check a whole product for fungal-acne triggers →

Is Isononyl Isononanoate comedogenic?

Isononyl Isononanoate has a comedogenicity rating of 1/5 — a very low pore-clogging risk. Remember that where an ingredient sits in the list matters: Isononyl Isononanoate near the top means a higher concentration and more impact than the same ingredient near the end.

Similar acne-safe ingredients

Isononyl Isononanoate is already a low-risk choice. Other acne-safe options you may see alongside it include:

• Glyceryl Stearate — Low risk · 1/5
• Isohexadecane — Low risk · 1/5
• Caprylic/Capric Triglyceride — Low risk · 1/5
• Cetearyl Ethylhexanoate — Low risk · 1/5
• Coco-Caprylate — Low risk · 1/5

How we rate comedogenicity — and its limits

The 0–5 comedogenicity scale comes from dermatology research that measured how much individual ingredients clogged pores, originally using the rabbit-ear assay (Fulton et al., 1984). A rating reflects an ingredient's potential to clog pores at high concentration — not a guarantee that any finished product will break you out.

That distinction matters. A later review (Draelos & DiNardo, 2006) found that a single ingredient's comedogenic score does not reliably predict how a complete formula behaves on real skin: concentration, the rest of the formula, and your own skin all change the result. So read Isononyl Isononanoate's 1/5 as a risk signal — most useful when the ingredient sits near the top of the list — rather than a verdict on one specific product.

AcneSafeCheck compiles published comedogenicity ratings and dermatology references into one searchable database. It is educational, not a lab test of your specific product, and not medical advice.

References

1. Fulton JE Jr, Pay SR, Fulton JE III. Comedogenicity of current therapeutic products, cosmetics, and ingredients in the rabbit ear. J Am Acad Dermatol. 1984;10(1):96–105. PubMed
2. Draelos ZD, DiNardo JC. A re-evaluation of the comedogenicity concept. J Am Acad Dermatol. 2006;54(3):507–512. PubMed
3. American Academy of Dermatology. Acne: causes, treatment and skin-care guidance. aad.org

By Mitchell Zandwijken · Rated against the published comedogenicity references above · Last updated July 2026.