10 Surprising Acne Causes (and How to Fix Them)
Acne Cause #1: Dairy (Milk, Yogurt, Whey Protein)
Why it causes acne:
Dairy contains hormones (including IGF-1 and androgens) that can stimulate oil production and increase inflammation—two big acne triggers. Whey protein is especially known to spike insulin levels, which may worsen breakouts.
What to do about it:
Try a dairy-free challenge for 3–4 weeks and monitor your skin. Swap whey protein for plant-based alternatives like pea or hemp protein. If reintroducing dairy, stick to full-fat or fermented options, which are typically less inflammatory.
Acne Cause #2: High-Glycemic Foods (Oat Milk, Soda, Added Sugars)
Why it causes acne:
Foods that spike your blood sugar (like oat milk, soda, white bread, or even natural sweeteners like honey in excess) trigger a surge in insulin and IGF-1, which ramp up sebum production and inflammation.
What to do about it:
Balance your blood sugar with high-fiber, whole foods and protein-rich meals. Avoid sugary beverages, and switch to low-GI sweeteners like monk fruit or stevia. Check your oat milk label—it often contains added sugar.
Acne Cause #3: Sweat / Not Showering After Workouts
Why it causes acne:
Sweat, bacteria, and friction from tight workout clothes can clog pores and create the perfect environment for breakouts—especially on the chest, back, and jawline.
What to do about it:
Shower immediately after workouts. Use a gentle exfoliating body wash with salicylic acid or benzoyl peroxide. If you can’t shower, use micellar water wipes or a clean, damp washcloth to wipe down sweaty skin ASAP.
Acne Cause #4: Products That Are Too Harsh
Why it causes acne:
Harsh cleansers, toners, or overuse of exfoliants can strip your skin’s natural barrier (aka the acid mantle). A compromised barrier leads to inflammation, sensitivity, and even more breakouts.
What to do about it:
If your moisturizer stings or your skin feels tight, it’s a sign your barrier is damaged. Switch to fragrance-free, barrier-repairing products with ingredients like ceramides and niacinamide. T
Discover which products are right for your skin in minutes with the Skin Quiz.
Acne Cause #5: Washing Detergent, Fabric Softeners and Dryer Sheets
Why it causes acne:
Laundry detergents, fabric softeners and dryer sheets with fragrance, dyes, and ingredients like sodium lauryl sulfate (SLS) can leave a waxy residue on your pillowcase and irritate your skin—especially if you always sleep on the same side.
What to do about it:
Switch to a gentle, hypoallergenic detergent like:
- Tide Free & Gentle
- Seventh Generation Free & Clear
- Wash pillowcases at least once a week and avoid fabric softeners.
Acne Cause #6: Shampoo and Conditioner
Why it causes acne:
Heavy, fragranced, or silicone-rich shampoos and conditioners can leave residue that rinses down your face, chest, or back during showers—especially if you don’t cleanse your skin after rinsing your hair.
What to do about it:
Use a non-comedogenic shampoo like:
- Vanicream Free & Clear
- SEEN Shampoo (developed by a dermatologist)
- Always wash your face and body after rinsing out your hair.
Acne Cause #7: Medications
Why it causes acne:
Some medications, including thyroid meds, birth control, and even spironolactone, can contain fillers or cause hormonal fluctuations that trigger acne.
What to do about it:
Talk to your doctor about switching brands—people often find relief with a different formulation. Brand-name versions tend to be more consistent. Reddit and skincare forums are great for crowdsourced insights on this.
Acne Cause #8: Biotin or Excess B12 Supplementation
Why it causes acne:
Biotin competes with vitamin B5, which is essential for skin barrier function, and may disrupt skin clarity in high doses. Similarly, too much B12 may overstimulate acne-causing bacteria.
What to do about it:
Avoid biotin supplements if you're acne-prone. For B12, try to stay within a range of 300–700 pg/mL, unless otherwise recommended by your doctor. Monitor your skin if you're taking higher doses for deficiency.
Acne Cause #9: Pore-Clogging Makeup and Skincare
Why it causes acne:
Some products contain comedogenic ingredients (like coconut oil, lanolin, or certain silicones) that clog pores—especially if left on overnight or used repeatedly.
What to do about it:
Check your products on a comedogenicity scale (you can search ingredients on sites like CosDNA). Look for makeup labeled “non-comedogenic” or “oil-free.” Check out the Best Non-Comedogenic Moisturizers for Acne-Prone Skin. Double cleanse if you wear makeup daily.
Acne Cause #10: Dirty Makeup Brushes & Pillowcases
Why it causes acne:
Brushes and pillowcases collect oil, bacteria, and old product—all of which can be transferred back onto your skin, leading to breakouts.
What to do about it:
Wash makeup brushes weekly with a gentle cleanser. Swap out pillowcases at least once a week—more often if you have oily or acne-prone skin.
How to Treat Acne: A Multi-Pronged Approach
If you have acne-prone skin, managing breakouts usually requires a combination of internal and external changes.
1. Supplements & Medications for Acne
Certain supplements can support clearer skin by addressing inflammation, hormone regulation, and nutrient deficiencies:
- Omega-3s (with DHA + EPA): Help reduce inflammation, balance hormones, and regulate sebum production. Try: Microbiome Labs MegaMarine Omega-3
- Zinc Picolinate: Supports immune function and reduces inflammation. Try: Thorne Zinc Picolinate 30mg
- Chromium Picolinate: Helps stabilize blood sugar, especially for hormonal acne. Try: Thorne Chromium Picolinate
In more severe cases: Speak with your dermatologist about:
- Oral antibiotics
- Spironolactone (a hormone blocker)
- Isotretinoin (Accutane)
2. Acne Diet
- Eliminate or limit dairy and high-GI foods.
- Try a Whole30-style reset to identify triggers.
3. Topicals & Skincare for Acne
- Look for: salicylic acid, benzoyl peroxide, glycolic acid, niacinimide
- For moderate/severe acne: consider clindamycin + benzoyl peroxide combos or retinoids.
- Take the Skin Quiz to get tailored product recs.
FAQs About Acne Causes
What foods commonly cause acne?
Dairy and high-glycemic foods like sugar, white bread, and oat milk with added sugars spike blood sugar and increase oil production.
How do I follow an acne-free diet?
Start with an elimination diet like Whole30 to find your triggers. Focus on whole, anti-inflammatory foods.
What products or ingredients cause acne?
Anything with comedogenic or irritating ingredients: certain makeup, skincare, shampoo, detergent, or even toothpaste with SLS and fragrance.
What supplements are good (and bad) for acne?
Good: Omega-3s (DHA/EPA), zinc picolinate, chromium picolinate
Bad: Biotin and excess B12 (unless deficient)
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