# Acne myths: toothpaste, dirty skin, the sun, diet, 'biofilm' and more, fact-checked URL: https://dermalguide.com/articles/acne-myths/ Part of: https://dermalguide.com/acne/ Published: 2026-10-18 ยท Updated: 2026-10-22 > Common acne myths fact-checked against dermatology sources: dirty skin, toothpaste, sun, diet, popping, purging, 'biofilm' and why more products don't work faster. ## Short answer Acne isn't caused by dirty skin, and blackheads aren't dirt: the NHS says the causes are beneath the skin. Toothpaste irritates spots rather than drying them, and there's no good evidence the sun clears acne. Diet may play a small role, mainly high-glycemic foods and milk. "Biofilm" is a research theory, not an established cause. What works is consistent treatment for 6 to 8 weeks. ## What this means for you ### Start with what you notice Check a claim against what dermatologists actually say before you change your routine. ### The ingredient names, translated Lots of acne advice is wrong. Washing more, scrubbing, toothpaste and sunbathing don't help and can make things worse. Food might matter a little for some people. Acne isn't contagious and isn't only for teenagers. Proven treatments work, but they take about two months. ### How to decide - If the advice names no cause beneath the skin, it is not a treatment plan. - More product or a higher percentage does not mean faster results. Consistency over six to eight weeks does. - Scrubbing, toothpaste, sunbathing and picking can all make a spot worse rather than better. - If a claim about a cause is new, treat it as a theory, not a reason to buy something. ### What to expect Expect most of these claims to be wrong or unproven rather than dramatically right. The useful part is the same for every myth: pick one supported treatment and judge it over about two months. General guidance, not a test of these products: [Acne: causes (NHS)](https://www.nhs.uk/conditions/acne/causes/); [Acne: overview (NHS)](https://www.nhs.uk/conditions/acne/); [Habits that can worsen acne (American Academy of Dermatology)](https://www.aad.org/public/diseases/acne/skin-care/habits-stop); [Diet and acne (American Academy of Dermatology)](https://www.aad.org/public/diseases/acne/causes/diet); [Adult acne (American Academy of Dermatology)](https://www.aad.org/public/diseases/acne/really-acne/adult-acne); [Pimple popping: why only a dermatologist should do it (American Academy of Dermatology)](https://www.aad.org/public/diseases/acne/skin-care/popping); [Acne treatment: how dermatologists treat acne (American Academy of Dermatology)](https://www.aad.org/public/diseases/acne/derm-treat/treat); [Back acne: how to get rid of it (American Academy of Dermatology)](https://www.aad.org/public/diseases/acne/diy/back-acne); [Yentzer BA, McClain RW, Feldman SR. Do topical retinoids cause acne to 'flare'? J Drugs Dermatol. 2009;8(9):799-801 (PMID 19746671)](https://scholarlyworks.lvhn.org/medicine/2174); [Innate immunity and bacterial biofilm theory of acne (PMID 23392942)](https://pubmed.ncbi.nlm.nih.gov/23392942/); [Cutibacterium (Propionibacterium) acnes biofilm and acne (PMID 19671069)](https://pubmed.ncbi.nlm.nih.gov/19671069/); [Makeup and acne (American Academy of Dermatology)](https://www.aad.org/public/diseases/acne/causes/makeup); [How to treat different types of acne (American Academy of Dermatology)](https://www.aad.org/public/diseases/acne/diy/types-breakouts). Each product's label source is linked on its product page. ## Myth: acne is caused by dirty skin **False.** The [NHS](https://www.nhs.uk/conditions/acne/causes/) says acne isn't caused by poor hygiene, because the biological causes happen beneath the skin. Acne starts when hair follicles get blocked by oil and dead skin cells, and is driven by hormones, genetics and inflammation. Washing more doesn't help either. The NHS says washing more than twice a day may aggravate the skin, and the [AAD](https://www.aad.org/public/diseases/acne/skin-care/habits-stop) recommends washing twice a day plus after sweating. ## Myth: blackheads are dirt in your pores **False.** The [NHS](https://www.nhs.uk/conditions/acne/) says blackheads aren't filled with dirt; they're dark because of pigment produced by the lining of the hair follicle. Many "blackheads" on the nose aren't even blackheads; see [blackheads vs sebaceous filaments](https://dermalguide.com/articles/blackheads-vs-sebaceous-filaments/). ## Myth: scrubbing harder clears acne **False.** The [AAD](https://www.aad.org/public/diseases/acne/skin-care/habits-stop) says scrubbing irritates skin and can make acne flare. Use a mild cleanser with your fingertips and pat dry. ## Myth: put toothpaste on a pimple **False.** The [NHS](https://www.nhs.uk/conditions/acne/causes/) says that although toothpaste contains antibacterial ingredients, it can irritate and damage the skin, so it isn't recommended. Use a thin layer of benzoyl peroxide, [salicylic acid](https://dermalguide.com/ingredients/salicylic-acid/) or adapalene instead. See [pimple patches and spot treatments](https://dermalguide.com/articles/pimple-patches-spot-treatments/). ## Myth: the sun (or a sunbed) clears acne **False.** The [NHS](https://www.nhs.uk/conditions/acne/causes/) says there's no conclusive evidence that sunbathing or sunbeds improve acne. Some acne medicines make skin more sensitive to light, and sun exposure damages skin and raises skin cancer risk. The [AAD](https://www.aad.org/public/diseases/acne/diy/back-acne) adds that sun can darken acne and make it last longer, which is why marks can look worse after a summer. > **Skin Realist check:** a tan can hide redness for a while, which is probably where this myth comes from. It doesn't treat the acne, and the marks are often darker when the tan fades. ## Myth: diet has nothing to do with acne (or everything) **Both are overstated.** The [AAD](https://www.aad.org/public/diseases/acne/causes/diet) says: - small studies suggest a **low-glycemic diet** may reduce acne, though other studies found no link - **all types of cow's milk** (whole, low-fat and skim) have been linked to acne - **no studies have found that yogurt or cheese** lead to more breakouts - more research is needed, and clear skin still needs skin care and acne treatment The [NHS](https://www.nhs.uk/conditions/acne/causes/) also lists high-glycemic diets as a possible trigger. So diet may be a factor for some people, but cutting out foods is rarely enough on its own. If you suspect a food, the AAD suggests seeing whether avoiding it makes a difference. ## Myth: popping a pimple makes it heal faster **False.** The [AAD](https://www.aad.org/public/diseases/acne/skin-care/popping) says popping at home often pushes material deeper into the skin, increasing inflammation, and can lead to permanent scars, more noticeable acne, more pain and infection. A dermatologist can extract blackheads and whiteheads or inject a painful cyst safely. ## Myth: acne is contagious **False.** The [NHS](https://www.nhs.uk/conditions/acne/causes/) says you can't pass acne on to other people. ## Myth: sex or masturbation affects acne **False.** The [NHS](https://www.nhs.uk/conditions/acne/causes/) says having sex or masturbating doesn't make acne better or worse. ## Myth: only teenagers get acne **False.** The [AAD](https://www.aad.org/public/diseases/acne/really-acne/adult-acne) says some adults keep getting acne into their 30s, 40s and 50s, and some get it for the first time as adults; women are more often affected. The [NHS](https://www.nhs.uk/conditions/acne/) says about 3% of adults over 35 have acne. See [hormonal and jawline acne](https://dermalguide.com/articles/hormonal-jawline-acne/). ## Myth: people with acne shouldn't wear makeup or moisturiser **False.** The [AAD](https://www.aad.org/public/diseases/acne/causes/makeup) says people with acne can wear makeup if they choose non-comedogenic products and remove them every night. And the [AAD](https://www.aad.org/public/diseases/acne/skin-care/habits-stop) says dry, irritated skin can lead to more acne, recommending a moisturiser for acne-prone skin twice a day. See [makeup for acne-prone skin](https://dermalguide.com/articles/makeup-for-acne-prone-skin/). ## Myth: more product (or a higher percentage) works faster **False.** The [AAD](https://www.aad.org/public/diseases/acne/derm-treat/treat) says applying more medication than recommended doesn't clear acne faster, and the [AAD](https://www.aad.org/public/diseases/acne/skin-care/habits-stop) lists switching treatments every week or so as a habit that irritates skin. Higher strengths mostly add irritation. See [OTC acne treatments compared](https://dermalguide.com/articles/otc-acne-treatments-compared/). ## Myth: retinoid "purging" means it's working **Partly true, often misused.** The adapalene Drug Facts label says acne may seem to worsen in the early weeks before it improves. But a 2009 review in the [*Journal of Drugs in Dermatology*](https://scholarlyworks.lvhn.org/medicine/2174) concluded it's unlikely that starting a topical retinoid causes acne to flare, and attributed early worsening to acne's natural course. Either way, getting worse **beyond 6 to 8 weeks**, or bumps in new places, isn't purging. See [closed comedones](https://dermalguide.com/articles/closed-comedones-whiteheads/). ## Myth: "biofilm" is the hidden cause of your acne **Overstated.** Some brand blogs claim acne is really caused by bacterial **biofilms**, protective layers bacteria build inside follicles, and sell products to "break them up". This comes from a genuine research theory: papers such as [PMID 23392942](https://pubmed.ncbi.nlm.nih.gov/23392942/) and [PMID 19671069](https://pubmed.ncbi.nlm.nih.gov/19671069/) describe how *Cutibacterium acnes* biofilms and the immune response might contribute to acne. But a theory about mechanism isn't proof that a "biofilm" product works. We found no clinical trials showing products marketed against biofilm clear acne better than standard treatments. The treatments with strong evidence are still benzoyl peroxide, retinoids and, for some people, prescription options. ## Myth: acne will go away on its own, so it isn't worth treating **Risky.** The NHS says many people's acne improves with age, but the [AAD](https://www.aad.org/public/diseases/acne/diy/types-breakouts) says deep nodules and cysts often cause permanent scars, and the sooner you treat them, the fewer scars you'll have. Acne can also affect mood and confidence. Effective treatment exists; see [when to see a dermatologist](https://dermalguide.com/articles/acne-when-to-see-a-dermatologist/). ## Frequently asked questions ### Is acne caused by dirty skin? No. The NHS says acne isn't caused by poor hygiene, because its causes happen beneath the skin. Washing more than twice a day can actually aggravate it. ### Does toothpaste get rid of pimples? No. The NHS says toothpaste contains antibacterial ingredients but can irritate and damage the skin, so it isn't recommended. Use a thin layer of a real acne treatment instead. ### Does the sun help acne? There's no conclusive evidence that sunbathing or sunbeds help, according to the NHS. Some acne medicines increase sun sensitivity, and the AAD says sun can darken acne marks and make them last longer. ### Does chocolate or dairy cause acne? The evidence is limited. The AAD says small studies suggest high-glycemic diets may worsen acne and that all types of cow's milk have been linked to acne, but no studies found that yogurt or cheese cause breakouts. Diet alone rarely clears acne. ### Is acne contagious? No. The NHS says acne can't be passed to other people. ### Is 'biofilm' the real cause of acne? It's a research theory, not an established cause. Some researchers propose that acne bacteria form protective biofilms in follicles, but treatments marketed as "biofilm-busting" aren't backed by clinical trials showing they work better. ### Is retinoid purging real? Partly. The adapalene label says acne may seem worse in the early weeks, but a review concluded retinoids are unlikely to cause true flares; early worsening may be acne's natural ups and downs. Worsening beyond 6 to 8 weeks isn't purging. ### Do only teenagers get acne? No. The AAD says some adults get acne into their 30s, 40s and 50s, and some get it for the first time as adults, especially women. Amazon links on this site are affiliate links. This is general information, not medical advice.