If you’re scanning ingredient lists looking for anything rated above a “2” on the comedogenic scale…

You’ve been distracted.

Most breakouts are not caused by a single “pore-clogging” ingredient.

They’re driven by inflammation, altered keratinization, sebaceous dysregulation, and immune signaling within the pilosebaceous unit.¹

And the comedogenic scale? It’s far less definitive than marketing suggests.

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The Comedogenic Scale Is Based on Rabbit Ear Models

Much of the original comedogenicity data originated from rabbit ear assays conducted in the 1970s and 1980s.²

Rabbit ear follicular epithelium is significantly more reactive than human facial skin, making it prone to exaggerated microcomedone formation.³

Translation:
An ingredient rated “3” in a rabbit model does not automatically clog human pores.

Modern dermatology recognizes that these early models have limitations when applied directly to real-world human skin physiology.⁴

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“Non-Comedogenic” Is Not a Strictly Regulated Term

In many regulatory frameworks, “non-comedogenic” does not require standardized global testing criteria.⁵

Brands may rely on:

• Internal testing

• Outdated data

• Ingredient reputation

• Marketing positioning

The label feels definitive.
The science is contextual.

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What Actually Causes Comedones?

Acne pathogenesis involves four primary mechanisms:¹

1. Increased sebum production

2. Follicular hyperkeratinization

3. Cutibacterium acnes proliferation

4. Inflammatory cascade activation

Comedone formation begins with abnormal keratinocyte shedding within the follicle — not simply the presence of topical oils.⁶

Inflammation is now understood to be present even before visible lesions develop.⁷

This shifts the focus from ingredient fear to biological regulation.

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Not All Oils Are Comedogenic in Practice

Comedogenicity depends on:

• Concentration

• Vehicle

• Penetration profile

• Oxidative stability

• Individual sebum composition

Studies have demonstrated that certain lipid components can support barrier repair without increasing comedone formation in humans when properly formulated.⁸

Context matters more than isolated ingredient lists.

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Barrier Damage Worsens Congestion

Excessive exfoliation and harsh cleansing increase transepidermal water loss (TEWL), impair barrier lipids, and amplify inflammatory mediators.⁹

Barrier disruption may increase follicular instability and exacerbate breakouts — even when products are labeled non-comedogenic.¹⁰

In other words:

Over-stripping can create the very congestion you’re trying to prevent.

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The Real Takeaway

Comedogenicity is not binary.

It is influenced by:

• Dose

• Delivery system

• Skin type

• Sebum composition

• Existing inflammation

• Hormonal signaling

Clear skin is achieved by stabilizing:

• Keratinocyte turnover

• Sebaceous regulation

• Inflammatory response

• Barrier integrity

Not by eliminating entire ingredient categories based on outdated scales.

Marketing simplifies.

Skin biology does not.

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References

1. Gollnick HPM. Pathogenesis and management of acne. J Am Acad Dermatol.

2. Fulton JE et al. Comedogenicity of current therapeutic products. J Soc Cosmet Chem.

3. Kligman AM. The rabbit ear assay revisited. Arch Dermatol.

4. Draelos ZD. Comedogenicity testing and human relevance. Dermatol Clin.

5. U.S. FDA Cosmetic Labeling Guidance – non-comedogenic claims.

6. Plewig G, Kligman AM. Acne and Rosacea. Springer.

7. Jeremy AHT et al. Inflammatory events precede acne lesion formation. Br J Dermatol.

8. Elias PM. Skin barrier function and lipid biology. J Invest Dermatol.

9. Voegeli R et al. Barrier disruption and acne pathophysiology. Skin Pharmacol Physiol.

10. Tan JKL. Irritation and acne exacerbation mechanisms. J Cutan Med Surg.