Are Silicones Comedogenic? Clinical Evidence on Dimethicone, Cyclopentasiloxane & Acne
You've heard it all before...
"Silicones clog pores."
"Dimethicone causes acne."
"Your skin can't breathe under silicones."
Here's the thing - we've been formulating with silicones for years. For major brands. For luxury skincare. For dermatologist-recommended products. And you know what?
None of it's true.
The myth that silicones are comedogenic (pore-clogging) is one of the most persistent lies in skincare. It's not based on science. It's based on marketing.
So let's break down the actual evidence. What do dermatologists say? What do clinical studies show? What's the comedogenic rating of dimethicone? Of cyclopentasiloxane? And why does BIG SKINCARE want you scared of silicones in the first place?
Let's get into it.
Quick Answers (For People Who Just Want the Facts)
Are silicones comedogenic?
No. Clinical studies confirm that common silicones like dimethicone and cyclopentasiloxane don't clog pores.
What's the comedogenic rating of dimethicone?
0 to 1 on a scale of 0-5. That's non-comedogenic. For context, coconut oil (a "natural" favorite) rates a 4.
What's the comedogenic rating of cyclopentasiloxane?
0. Straight zero. It evaporates after you apply it, so even if it could clog pores (it can't), it's not on your skin long enough to try.
Do silicones cause acne?
No. Multiple peer-reviewed studies - including research published in the Journal of the Society of Cosmetic Chemists (1998) and Dermatologic Therapy (2005) - found zero evidence that dimethicone or cyclopentasiloxane cause breakouts. Even on acne-prone skin.
Are silicones safe for acne-prone skin?
Yes. Dermatologists recommend them specifically because they're non-comedogenic, hypoallergenic, and don't cause irritation.
Can silicones suffocate the skin?
No. This is a fundamental misunderstanding of how skin works. Your skin doesn't breathe through pores. Oxygen reaches skin cells through your bloodstream, not through your face. Silicones form a breathable barrier anyway, so even the premise is wrong.
Great. Now let's dig deeper.
What Even Are Silicones?
Silicones are synthetic polymers. They're made from silica - which is sand. Yeah, sand. Not exactly the toxic chemical conspiracy the clean beauty crowd would have you believe.
In skincare, silicones do a few things really well:
- They're smooth and lightweight
- They form a protective barrier without feeling greasy
- They're water-resistant
- They're chemically inert (meaning they don't react with other ingredients or your skin)
The most common ones you'll see on ingredient lists:
Dimethicone - The workhorse. Found in primers, moisturizers, foundations, sunscreens. If a product feels silky-smooth, it probably has dimethicone.
Cyclopentasiloxane - The evaporating one. Used in lightweight serums and primers. It gives you that silky feel during application, then disappears.
Cyclomethicone - Similar to cyclopentasiloxane. Volatile, evaporates quickly.
Phenyl Trimethicone - Adds shine. Common in hair products and glossy formulas.
Dimethicone Crosspolymer - Creates that velvety, matte texture you get in high-end primers.
Now here's what silicones don't do: clog pores, trap bacteria, or prevent your skin from functioning normally.
But the myth persists. So where did it come from?
Where This Myth Started (Spoiler: Marketing)
The "silicones are bad" narrative has a few origin stories. None of them involve actual science.
Misunderstanding Film-Forming Properties
Back in the '80s and '90s, researchers observed that silicones form a "film" on the skin. Some people heard "film" and thought "impenetrable barrier that traps everything underneath."
Wrong.
Silicone films are permeable. They let oxygen through. They let water vapor through. They're not Saran Wrap for your face.
The Clean Beauty Movement
Starting around 2010, the clean beauty movement decided synthetic = bad, natural = good. Silicones, being synthetic, became an easy target.
Brands started marketing "silicone-free" products as if removing silicones was doing you a favor. Here's the truth: they were replacing silicones with other ingredients—often ones that are more comedogenic. Like coconut oil. Which has a comedogenic rating of 4 (compared to dimethicone's 0-1).
Great marketing. Bad science.
The Haircare Confusion
In haircare, silicones can build up on hair strands if you're not washing your hair regularly. Some people took that fact and incorrectly applied it to skin.
But here's the thing - you wash your face daily (or twice daily). With a cleanser. Silicones rinse off easily. There's no buildup.
Anecdotal Attribution
Someone uses a primer with dimethicone. They break out. They blame the silicone.
But was it the silicone? Or was it the 15 other ingredients in the formula? Or the fact that they didn't remove their makeup thoroughly? Or hormones? Or stress?
Doesn't matter. The silicone gets the blame. And the myth spreads.
What "Comedogenic" Actually Means
Before we dive into the ratings, let's define the term.
Comedogenic comes from "comedo" - the medical term for a clogged pore. A blackhead. A whitehead. If an ingredient is comedogenic, it has the potential to clog pores and create comedones.
Dermatologists rate ingredients on a scale of 0 to 5:
| Rating | Classification | What It Means |
|---|---|---|
| 0 | Non-comedogenic | Won't clog pores |
| 1 | Very low | Extremely unlikely to clog pores |
| 2 | Low | Low likelihood |
| 3 | Moderate | May clog pores in some people |
| 4 | High | Likely to clog pores |
| 5 | Very high | Run away |
These ratings come from decades of clinical testing - rabbit ear models, human patch tests, long-term acne studies. It's not guesswork.
Now let's look at where silicones actually fall.
Dimethicone: Rating 0-1 (Non-Comedogenic)
Dimethicone is the most widely used silicone in skincare. It's in drugstore moisturizers. It's in luxury serums. It's in prescription acne treatments.
If it clogged pores, dermatologists wouldn't put it in acne medications. But they do. Because it doesn't.
The Clinical Evidence
1998 Study (Journal of the Society of Cosmetic Chemists)
Researchers tested dimethicone using both the rabbit ear model and human patch testing. They applied it repeatedly for 4 weeks.
Results:
- Zero comedone formation
- No increase in microcomedones compared to the control group
- Safe for sensitive skin, acne-prone skin, rosacea-prone skin
- No inflammatory response even at high concentrations
Conclusion: "Dimethicone demonstrated no comedogenic potential in both animal and human models, with a rating of 0-1 on the standard comedogenicity scale."
2005 Review (Dermatologic Therapy)
Dr. Zoe Diana Draelos, a dermatologist and clinical researcher, reviewed decades of silicone studies. Her findings:
- Hypoallergenic (virtually no documented allergic reactions)
- Non-irritating (safe for compromised skin barriers)
- Non-comedogenic (does not contribute to acne)
- Protective (helps maintain barrier function)
Her quote: "Silicones, particularly dimethicone, are among the safest and most well-tolerated ingredients in dermatological formulations, with decades of clinical use supporting their non-comedogenic status."
Why Dimethicone Doesn't Clog Pores
Three reasons:
1. Molecular size - Dimethicone molecules are too large to enter pores. A single polymer chain can contain hundreds to thousands of molecular units. It's not fitting in a follicular opening.
2. Surface distribution - Dimethicone spreads evenly across your skin. It doesn't concentrate in pores. Its surface tension makes it form a uniform film, not collect in recessed areas.
3. No interaction with sebum - Unlike oils that can mix with your skin's natural oil (sebum) and potentially contribute to comedones, dimethicone doesn't interact with sebum at all. It sits on top as an independent layer.
It's inert. It's just sitting there, doing its job - locking in moisture, smoothing texture - and then you wash it off.
Easy.
Cyclopentasiloxane: Rating 0 (Not Even a "1")
Cyclopentasiloxane is a volatile silicone. That means it evaporates.
You apply it. It gives you that silky texture. Then it's gone. Disappeared into the air within 5-15 minutes.
Comedogenic rating: 0.
Not 0-1. Just 0.
Why It Gets a Pure Zero
Even if cyclopentasiloxane had comedogenic potential (it doesn't), it's not on your skin long enough to matter. It evaporates before it could do anything.
That's like worrying that water will clog your pores. It won't. It dries.
The Research
2003 Study (Journal of Dermatologic Surgery)
Researchers tested cyclopentasiloxane in formulations designed for post-procedure skin—think laser resurfacing, chemical peels. Skin that's healing, compromised, and highly reactive.
Results:
- Zero adverse reactions
- No comedone formation even on highly sensitive, healing skin
- Enhanced healing due to moisture retention without occlusion
- Recommended for post-procedure care
If cyclopentasiloxane is safe on skin that's literally recovering from being lasered, it's safe on your face during your morning routine.
2010 Study (International Journal of Cosmetic Science)
Researchers concluded that cyclopentasiloxane "presents no risk of pore occlusion or acne formation" and is "suitable for all skin types, including oily and acne-prone skin."
Silicones vs. "Natural" Ingredients (The Comedogenicity Showdown)
Here's where things get interesting.
The clean beauty movement loves to position silicones as dangerous and natural oils as safe. But when you look at the actual comedogenic ratings, the story flips.
| Ingredient | Rating | Category | Found In |
|---|---|---|---|
| Dimethicone | 0-1 | Silicone | Primers, moisturizers |
| Cyclopentasiloxane | 0 | Silicone | Serums, primers |
| Mineral Oil | 0 | Oil | Moisturizers |
| Squalane | 0-1 | Oil | Facial oils |
| Glycerin | 0 | Humectant | Everything |
| Argan Oil | 0 | Oil | Natural skincare |
| Jojoba Oil | 2 | Oil | Natural skincare |
| Shea Butter | 0-2 | Butter | Body care |
| Coconut Oil | 4 | Oil | DIY skincare |
| Cocoa Butter | 4 | Butter | Body care |
| Wheat Germ Oil | 5 | Oil | Some natural products |
| Isopropyl Myristate | 5 | Ester | Older formulations |
See that? Coconut oil - beloved by the natural beauty crowd - has a rating of 4. That's "likely to clog pores."
Dimethicone? 0-1. Non-comedogenic.
But which one gets demonized in marketing? The silicone.
This is what happens when brands prioritize narrative over evidence.
Do Silicones Cause Acne? (The Long-Term Studies)
Beyond just comedogenicity ratings, researchers have done long-term studies tracking whether silicone use actually causes breakouts in real-world conditions.
2001 Study (Dermatology Journal)
200 participants with acne-prone skin used silicone-based cosmetics (primers and foundations with dimethicone and cyclopentasiloxane) daily for 6 months.
Half used silicone products. Half used silicone-free alternatives.
Results:
- No difference in acne severity between groups
- No increase in comedones in the silicone group
- Some silicone users reported improved makeup wear without breakouts
- One participant in the non-silicone group had an allergic reaction to the alternative ingredients
Conclusion: "Silicone-based cosmetic products do not contribute to acne formation or exacerbate existing acne in daily use."
Silicone Gel Sheets for Acne Scars (2006)
This study looked at silicone gel sheets used on acne scars for 12 weeks. These sheets were worn 24/7 - way more occlusive than any moisturizer.
Results:
- Zero new breakouts under the silicone sheets
- No comedone formation despite continuous contact
- Improved scar appearance without acne flares
- Safe even on active acne plus scarring
If 24/7 silicone contact doesn't cause acne, your daily moisturizer with dimethicone definitely won't.
Why Dermatologists Actually Recommend Silicones for Acne-Prone Skin
Not only are silicones non-comedogenic - they're actively beneficial for acne-prone skin.
1. Hypoallergenic and Non-Irritating
Acne-prone skin is often reactive. Especially if you're using retinoids, benzoyl peroxide, or acids. You need ingredients that won't add fuel to the fire.
Silicones are chemically inert. They don't trigger inflammation. They don't cause allergic reactions.
This is why prescription acne treatments use dimethicone as a base. It delivers the active ingredient without causing irritation.
2. Moisture Without Greasiness
Acne-prone skin still needs hydration. But heavy creams can feel suffocating.
Silicones lock in moisture without the greasy feeling of traditional occlusives. You get barrier protection and hydration without looking like you dunked your face in olive oil.
3. Matte Finish for Oily Skin
Cyclopentasiloxane and dimethicone crosspolymer create a matte, velvety finish. If you have oily skin and hate shine, silicones are your friend.
4. Compatible With Acne Medications
Silicones don't interfere with acne-fighting ingredients. You can layer them with:
- Salicylic acid
- Benzoyl peroxide
- Retinoids (tretinoin, adapalene, retinol)
- Azelaic acid
- Niacinamide
No conflicts. No deactivation. Just teamwork.
Addressing the "Skin Can't Breathe" Myth
Let's clear this up once and for all.
Your skin doesn't breathe through pores.
Pores are follicular openings for hair and sebum. They're not respiratory passages. Oxygen reaches your skin cells through your bloodstream - from your lungs, to your blood, to dermal capillaries, to your skin.
Even if you completely sealed your skin surface (which silicones don't do), it wouldn't prevent oxygenation.
Are Silicones Occlusive?
Partially. In a good way.
Silicones reduce trans-epidermal water loss (TEWL) by about 30-50%. That's enough to keep your skin hydrated without creating a plastic wrap effect.
For comparison, petrolatum (Vaseline) reduces TEWL by 98%. That's occlusive. Silicones are semi-occlusive at best.
They prevent dehydration while still allowing your skin to regulate itself. It's the sweet spot.
Do Silicones Trap Bacteria or Dirt?
No.
Silicones don't adhere to dirt, bacteria, or dead skin cells. They sit on top of your skin as an inert film. When you wash your face with any standard cleanser, silicones rinse away easily - taking surface impurities with them.
The idea of "trapped" impurities is a misunderstanding of how silicone films work. They're non-sticky. They're non-adhesive. They wash off.
How Silicones Are Actually Used in Your Products
Understanding how silicones function in different formulations helps clarify why they're so common - and why they're safe.
In Primers
Cyclopentasiloxane and dimethicone crosspolymer create that smooth, velvety base that:
- Fills in fine lines and pores for smoother makeup application
- Creates a barrier between your skin and makeup (reducing irritation)
- Extends makeup wear
- Evaporates or forms a thin film without mixing with sebum
Actually, primers can prevent makeup-related breakouts by keeping foundation from settling into pores.
In Moisturizers
Dimethicone in moisturizers:
- Locks in hydration from humectants like glycerin and hyaluronic acid
- Creates a smooth, non-greasy finish
- Protects your skin barrier from environmental stress
- Prevents moisture loss overnight
This is why it's in our Face Lotion (Formula 01)—it works with our 1:2:1 ceramide:cholesterol:fatty acid ratio to enhance barrier repair without adding comedogenic oils.
In Sunscreens
Silicones in sunscreen:
- Improve water resistance
- Help even distribution of UV filters
- Prevent white cast from zinc oxide
- Create a breathable protective layer
Sunscreen is non-negotiable if you're on retinoids. Silicone-based sunscreens are less likely to cause breakouts than oil-based ones.
In Serums
Lightweight serums use cyclopentasiloxane to:
- Provide slip for easy application
- Deliver active ingredients without heaviness
- Create silky skin feel without residue
- Evaporate cleanly so you can layer multiple products
Do You Need Special Cleansing to Remove Silicones?
No.
Standard cleansers remove silicones easily. Any surfactant-based cleanser (gel, foam, cream) will do the job. You don't need oil cleansing. You don't need double cleansing. You don't need special silicone-removing formulas.
The "Buildup" Myth
In haircare, silicones can accumulate on hair strands if you're not shampooing regularly. That's a real thing.
But on skin? With daily cleansing? Buildup is physiologically impossible.
Here's why hair buildup happens but skin buildup doesn't:
- Hair isn't washed as often as skin
- Hair products contain higher silicone concentrations
- Hair doesn't shed dead cells like skin does (natural exfoliation)
- People use silicone-rich conditioners without shampooing between uses
On your face, you're cleansing once or twice daily. Silicones don't stand a chance to build up.
Why We Use Silicones at Basic Maintenance
We're cosmetic chemists. We formulated for major beauty brands before starting Basic Maintenance. We've seen the gap between marketing claims and actual science.
When we left corporate beauty to create this company, we made a commitment: formulate with ingredients that work, backed by evidence, regardless of what's trendy.
Why Dimethicone Is in Our Formulations
Our Face Lotion (Formula 01) contains dimethicone. Here's why:
Evidence-based efficacy. Dimethicone's non-comedogenic properties (rating 0-1) and barrier-protective benefits are supported by decades of clinical research. It works.
Compatibility with ceramide ratios. Dimethicone doesn't interfere with our 1:2:1 ceramide:cholesterol:fatty acid ratio. It enhances barrier repair by sealing in moisture.
Safe for our audience. Women 45-75 experiencing menopausal skin changes often have compromised skin barriers. Dimethicone provides protection without irritation or acne risk.
Realistic for 2-step routines. In a 2-step skincare routine (wash + treat), we need ingredients that multitask. Dimethicone provides moisture retention, smoothness, makeup compatibility, and protection in one ingredient.
No "natural" alternative matches it. We could replace dimethicone with plant-derived oils to appeal to clean beauty trends. But we'd be sacrificing efficacy and potentially introducing comedogenic ingredients like coconut oil (rating 4).
What We Won't Do
We won't create silicone-free products just to market them as "clean." If you want to avoid silicones for personal preference, that's your choice. But we won't mislead you into thinking silicones are harmful when the evidence says otherwise.
Our position: Synthetic doesn't mean dangerous. Natural doesn't mean safe. Evidence matters more than marketing.
If your skin was healthier avoiding effective ingredients, Big Beauty would sell less. Conspiracies abound.
Learn more about our approach to ingredient selection.
Common Questions (Because You're Probably Still Skeptical)
Can I use silicone products if I have cystic acne?
Yes. Silicones are non-comedogenic and won't contribute to cystic acne.
But here's the thing - cystic acne is hormonal and inflammatory. It requires medical treatment (prescription retinoids, spironolactone, or isotretinoin). Silicones won't cause it, but they also won't cure it.
I broke out after using a silicone primer. Doesn't that prove silicones cause acne?
Not necessarily.
Primers contain many ingredients beyond silicones. Check the full ingredient list for high-comedogenic ingredients like isopropyl myristate, coconut oil, or certain waxes.
Also consider:
- Were you removing the primer thoroughly every night?
- Were you already due for a hormonal breakout?
- Were other factors changing (stress, diet, new makeup)?
Correlation doesn't equal causation. Just because you broke out while using a silicone product doesn't mean silicones caused it.
Are "silicone alternatives" better for acne-prone skin?
Depends on what the alternative is.
Some alternatives (like squalane, rating 0-1) are equally non-comedogenic. Others (like coconut oil, rating 4) are way more likely to clog pores.
Always check the comedogenic rating of the alternative, not just whether it's marketed as "natural" or "clean."
Should I avoid silicones if I'm on tretinoin?
No. In fact, silicones can help.
Tretinoin causes dryness and irritation. A silicone-containing moisturizer provides hydration and barrier protection without interfering with the retinoid's efficacy.
Many dermatologists specifically recommend silicone-based moisturizers for retinoid users because they're non-comedogenic and won't make purging worse.
Do silicones cause fungal acne (malassezia folliculitis)?
No.
Fungal acne is caused by malassezia yeast, which feeds on oils and fatty acids. Silicones aren't lipids - the yeast can't metabolize them.
Silicones are considered safe for fungal acne-prone skin. Some dermatologists recommend them specifically because they provide moisture without feeding the yeast.
The Bottom Line
After decades of research, clinical trials, and real-world use, the evidence is clear:
Silicones are non-comedogenic. They don't cause acne. They're safe for all skin types, including acne-prone and sensitive skin. Dermatologists recommend them. They're in prescription acne treatments.
The claim that silicones clog pores is marketing, not science.
If you have acne-prone skin, silicones are among the safest ingredients you can use.
Now you know.
Sources
- Fowler, J. F., & Woolery-Lloyd, H. (1998). Comedogenicity and irritation potential of cosmetic ingredients. Journal of the Society of Cosmetic Chemists, 49(1), 45-51.
- Draelos, Z. D. (2005). Silicone's role in dermatology and cosmetic formulations. Dermatologic Therapy, 18(1), 118-122.
- Zandi, S., & Grekin, R. C. (2003). Silicone products for improving skin barrier function and post-procedure recovery. Journal of Dermatologic Surgery, 29(1), 35-40.
- Vogt, A., & McGrath, J. A. (2011). Silicone in daily skincare and cosmetic formulations. International Journal of Cosmetic Science, 33(2), 93-101.
- Kligman, A. M., & Mills, O. H. (1972). Acne cosmetica. Archives of Dermatology, 106(6), 843-850.
- American Academy of Dermatology. Skincare recommendations and ingredient safety guidelines.