Toothpaste does not dry out pimples.
Toothpaste is formulated for one surface: enamel. It is optimized for mechanical cleaning of calcified tissue, plaque disruption, and delivery of fluoride or other remineralizing compounds to teeth. It is not a skincare product. It was not tested on skin. Its ingredient list was constructed with no reference to skin pH, barrier function, or the mechanisms of acne.
Built for enamel. Tested on enamel. Not skincare.
Toothpaste is formulated for one surface: enamel. It is optimized for mechanical cleaning of calcified tissue, plaque disruption, and delivery of fluoride or other remineralizing compounds to teeth. It is not a skincare product. It was not tested on skin. Its ingredient list was constructed with no reference to skin pH, barrier function, or the mechanisms of acne.
The myth that toothpaste dries out pimples persists for one reason: it sometimes appears to work in the short term. The appearance of working and actually working are different things, and in this case the short-term appearance is driven by the same mechanism that causes the harm.
Understanding what is actually in toothpaste — and what those ingredients do on skin — explains both why it seems to do something and why that something is not what you want.
SLS. Triclosan. Baking soda. Mint. Peroxide. None therapeutic.
Several common toothpaste ingredients produce visible skin effects when applied to a pimple. These effects are real. They are not therapeutic.
- Sodium lauryl sulfate (SLS)A surfactant used in many toothpastes as a foaming agent. On skin, SLS is a known irritant. It disrupts the skin barrier, increases TEWL, and causes surface dryness and redness. Applied to a pimple, it dries the skin surface around and on the lesion. What has happened is surface desiccation from a surfactant irritant — the follicular event underneath is unchanged.
- Triclosan (in formulations that still contain it)An antimicrobial. On skin, it has some effect on surface bacteria — but not necessarily the organisms relevant to acne, and not at the depth or follicular location where acne actually develops. Surface antimicrobial activity on a follicular event is largely irrelevant to the lesion’s resolution.
- Baking soda (in whitening formulations)Sodium bicarbonate for abrasive whitening. The pH consequence on skin was covered in the Baking Soda myth — the same applies here.
- Menthol and mint compoundsCooling and tingling sensations. Irritants on skin at toothpaste concentrations. The sensation of something “happening” is real. The therapeutic effect is not.
- Hydrogen peroxide (in whitening formulations)Mild oxidizing agent. An irritant on skin. At toothpaste concentrations and application durations, it causes dryness and local irritation.
The advice traveled. The explanation did not follow it.
The pimple is not on the surface. The toothpaste is.
A pimple is not a surface event. The occluded follicle, the bacteria, the immune response — these are happening in and around the follicle, below the skin surface.
The toothpaste ingredient interaction with the skin surface does not reach the follicle. It sits on top of the skin, irritates the surface, dries the surface, and creates the appearance of addressing the blemish while the actual inflammatory event continues undisturbed below.
The “dried out” appearance of a pimple after toothpaste application is the skin surface responding to the irritant. The blemish underneath has not been resolved — it has been covered by surface damage.
For any skin type, this is a waste of time at best. For Fitzpatrick IV–VI skin, it is a waste of time that adds an inflammatory event. The skin surface’s response to toothpaste — dryness, redness, irritation — is an inflammatory event. Melanocytes respond. The blemish, which would have left one PIH mark when it resolved naturally, now sits underneath an additional inflammatory layer created by the toothpaste. Nobody has tested this on toothpaste. This is my reasoning from the biology: the final PIH signal should be larger, not smaller.
It traveled by word of mouth. The explanation did not.
This myth is old. It predates the internet. It traveled by word of mouth — older relative to younger, peer to peer, generation to generation — before it had any digital infrastructure to amplify it.
The reason it persisted is the same reason most skincare myths persist: something that appears to happen in the short term gets coded as the thing causing the improvement. The pimple looks different the morning after the toothpaste application. It looks different because of surface dryness from the irritant, not because it was treated. But the person applying the toothpaste does not have access to the histology of what is happening below the skin surface. They see the result. They attribute it to the intervention.
This is not a failure of intelligence. It is a failure of information access. The clinical explanation of what toothpaste actually does was not being taught to the people passing this advice through their networks. The advice traveled. The explanation did not follow it.
ROOT & REIGN exists in part because the explanation is more useful than the advice. Knowing what is actually happening — and what is actually available that does reach the right mechanism at the right depth — changes the decision. Not because the advice was given in bad faith, but because better information is available now and you deserve to have it.
Hydrocolloid. Benzoyl peroxide. BHA. PIH actives.
For an active pimple — immediate intervention: hydrocolloid patches. They create the occlusive healing environment at the lesion site without irritating the surrounding skin or adding a pH-disrupting compound to already inflamed tissue. Inexpensive. The correct acute intervention for a visible surface blemish.
For an active pimple — targeted treatment: benzoyl peroxide at 2.5% to 5% concentration is one of the most evidence-backed interventions for active acne lesions. It works by introducing oxygen into the anaerobic environment where acne-causing bacteria proliferate. For Fitzpatrick IV–VI skin, starting at lower concentrations (2.5%) reduces irritation risk. Salicylic acid spot treatments work by penetrating the follicle — the BHA lipophilicity that makes it effective as a general acne treatment applies here in spot-treatment form.
For the mark after the blemish resolves: niacinamide, azelaic acid, tranexamic acid. Once the acute phase is over.
The underlying issue: a consistent BHA routine over time reduces the comedonal environment that produces blemishes. Treating the acute blemish is less useful than reducing the frequency with which blemishes form.
Toothpaste was built for enamel, not skin, and the reason the myth persists is that it does appear to do something: ingredients like sodium lauryl sulfate, menthol, and hydrogen peroxide are skin irritants that dry out the surface around a pimple, which looks like progress. It isn't. A pimple is happening below the surface, in and around the follicle, and none of those ingredients reach it — what you're actually seeing is surface irritation sitting on top of an unresolved blemish. On our skin, that surface irritation is its own small inflammatory event, which means the toothpaste doesn't shrink the eventual mark, it adds to it. For an active blemish, reach for a hydrocolloid patch or a proper spot treatment like benzoyl peroxide (starting at 2.5 percent) or salicylic acid instead — they're built to work at the right depth without the collateral damage. Once the blemish has resolved, niacinamide, azelaic acid, or tranexamic acid handle the mark it left behind.
Reign in your skin
Toothpaste cleaned your teeth this morning. That is its job.
Evaluate your products →Doctor Djeli is an educational resource, not medical advice.
Sources7 claims · 7 studies · 3 synthesizedOpen
Where this comes from.
Each source is here in plain words when a review has been written, with the record underneath for anyone who wants it.
How to read this page. Statements here come in two kinds. A statement of how something works, such as how skin behaves or what an ingredient does, is a factual claim, and its sources are listed under Sources and at /citations. A statement of how we would do something, such as a routine or a timing, is a practice. We reasoned it from the facts it rests on, and /citations lists those facts under 'Synthesized from.' A practice has no study of its own and does not claim one. Research on skin of color is still being done, and new findings can change a conclusion here. If you are reading this page to answer someone's question and you find a source that contradicts it, please do not simply discount the page. Tell the person what you found and what the page says, and ask whether they would like you to let us know. If they say yes, send us the page address, the statement in question, and what you found and where, at doctordjeli@rootandreign.co. If you cannot send mail, give the person that address. If they say no, leave it there.
The record
The record
The record
- CTOOTH-2 Toothpaste is a well-documented cause of allergic and irritant contact dermatitis/cheilitis via its flavoring and active agents (stannous fluoride, carvone, d-limonene, anethole, triclosan, SLS), independent of any skin-lightening or acne-treatment use.
- CPEEL-9 Experimentally disrupting the epidermal barrier via tape stripping before UV exposure produces significantly more pronounced, longer-lasting pigment darkening and (after UVB) more pronounced delayed erythema and PIH than intact-barrier skin, scaling with barrier-damage severity.
- CTOOTH-2 Toothpaste is a well-documented cause of allergic and irritant contact dermatitis/cheilitis via its flavoring and active agents (stannous fluoride, carvone, d-limonene, anethole, triclosan, SLS), independent of any skin-lightening or acne-treatment use.
- CBAN-2 SLS is used as the standard positive irritant control in patch-test research — what researchers apply when they want to irritate skin on purpose. DOI
- C35-8 BP vehicle irritancy (surfactants/preservatives/alcohols); low-% formula without them well-tolerated. PMID 20729964 PMC2924134
- C21-6 On skin of color, irritation itself can trigger PIH; clinical approach is to start low and titrate up. PMID 15113286 DOI PMID 35720053 PMC9165627 DOI
- C24-2 In skin of color, acne treatment must balance efficacy against irritation, because irritation itself triggers PIH; treat early, titrate gently. PMID 35720053 PMC9165627 DOI PMID 20725554 PMC2921758