The short answer is that you shouldn’t leave toothpaste on a pimple at all. While the classic advice suggests dabbing some on overnight, toothpaste is likely to leave you with a redder, more irritated spot than you started with. The ingredients that give toothpaste its cleaning power are too harsh for facial skin, and there are cheap, widely available alternatives that actually work.
Why Toothpaste Seems Like It Should Work
The idea behind this home remedy isn’t completely random. Toothpaste contains ingredients like baking soda, hydrogen peroxide, and alcohol, all of which can dry out skin. Hydrogen peroxide kills bacteria. Baking soda strips oils. In theory, slathering these onto a pimple should shrink it by pulling out moisture and fighting the bacteria inside.
Older toothpaste formulations also contained triclosan, an antibacterial agent that had some overlap with acne-fighting ingredients. That’s likely where this tip originally gained traction. But most toothpaste brands have moved away from triclosan, and the reasoning behind the advice no longer holds up even in theory.
What Actually Happens to Your Skin
Toothpaste is formulated for tooth enamel, which is the hardest substance in the human body. Facial skin is not remotely as tough. Many toothpastes have a pH between 8 and 10, making them significantly more alkaline than your skin, which sits around 4.5 to 5.5. That mismatch alone disrupts your skin’s protective acid mantle.
Sodium lauryl sulfate, the detergent that makes toothpaste foam, is a known skin irritant. It strips the oils your skin uses as a barrier, which can trigger irritant contact dermatitis, especially on the delicate skin around your mouth and cheeks. The result is redness, stinging, burning, and inflammation on top of the pimple you were trying to fix.
Baking soda compounds the problem. It doesn’t just dry the pimple; it removes the protective bacterial layer your skin maintains to fight infection and prevent breakouts. So even if the toothpaste temporarily dries out one spot, it can leave the surrounding area more vulnerable to new breakouts. You trade one pimple for a patch of raw, irritated skin that’s now prone to more acne.
The Overnight Risk
Leaving toothpaste on for several hours or overnight concentrates the damage. The longer these harsh ingredients sit on your skin, the more they strip, irritate, and inflame. A few minutes of contact might cause mild stinging. Several hours can produce something closer to a chemical burn, with peeling, dark spots, or lasting redness that takes days to heal.
People with sensitive skin, eczema, or rosacea face even higher risks. But even resilient skin types can develop contact reactions from the detergents and abrasives in modern toothpaste. Dermatologists have flagged toothpaste as a known cause of irritant reactions when it contacts skin directly, which is why even patch testing with undiluted toothpaste is considered unreliable in clinical settings.
What to Use Instead
Actual acne spot treatments cost a few dollars at any drugstore and contain ingredients formulated for skin at concentrations that have been tested for safety and effectiveness. The two most common options are benzoyl peroxide and salicylic acid.
- Benzoyl peroxide kills acne-causing bacteria and clears pores. Over-the-counter products typically come in 2.5% to 10% concentrations. Lower strengths work well for most people and cause less drying. You apply a thin layer directly to the pimple and leave it on.
- Salicylic acid dissolves the dead skin cells and oil clogging your pore. OTC spot treatments use around 2% concentration. It’s particularly effective for blackheads and whiteheads because it works inside the pore itself.
Both of these ingredients are pH-balanced for skin, tested at specific concentrations, and designed to target acne without destroying the surrounding skin barrier. A basic spot treatment with either ingredient will outperform toothpaste every time, without the redness, peeling, or risk of making things worse.
Quick Fixes That Are Safer Than Toothpaste
If you don’t have a spot treatment on hand, a few household alternatives are gentler than toothpaste. Holding ice wrapped in a cloth against an inflamed pimple for a few minutes can reduce swelling and redness. This won’t treat the pimple, but it calms the inflammation that makes it look worse.
Hydrocolloid patches, sometimes sold as “pimple patches,” are another option that’s become widely available. They absorb fluid from the pimple, protect it from picking, and create a moist healing environment. They won’t introduce harsh chemicals to your skin and can visibly flatten a whitehead overnight. For a last-minute solution, they’re far more effective and far less risky than reaching for the toothpaste tube.