The short answer: Not very well, based on most studies so far. In a randomized trial of 50 adults (48 finished), a peroxide-free routine of strips, toothpaste and rinse made no significant change in tooth color after 14 uses, while hydrogen peroxide strips did (Gurich et al., 2023). In two lab studies on extracted teeth, peroxide-free strips changed color no more than water (Cua et al., 2022) or were judged ineffective (Hul et al., 2026); one company-sponsored lab study of a different peroxide-free strip reported some improvement (Newman et al., 2025). PAP, the best-known peroxide-free whitener, has mixed lab results, and a 2025 review says clinical studies are still needed (Chan & Cao, 2025). Peroxide-free products look gentle on enamel in the lab, but if you want teeth that are actually lighter, peroxide products have the evidence (Eachempati et al., 2018).
Peroxide-free whitening strips are sold as the gentle choice: no peroxide, no sensitivity, sometimes with coconut oil or a purple tint. In October 2026, the National Advertising Division of BBB National Programs, an advertising watchdog, recommended that the maker of one peroxide-free strip keep its “30 minutes to whiter teeth” claim out of its ads, after finding that the company’s new supporting studies were flawed. The case was first brought by a maker of peroxide strips (BBB National Programs, 2026).
Big dental sites explain that most whitening strips work through peroxide (American Dental Association [ADA], 2022), but they rarely test the peroxide-free versions. This article looks at the head-to-head studies, what these strips use instead of peroxide, whether PAP and purple products work, whether they are safer, how to read whitening claims, and what works instead.
Do peroxide-free whitening strips work?
We found four studies that compared peroxide-free strips directly with peroxide strips. Three found little or no whitening from the peroxide-free strips:
- A trial in people. Fifty adults were randomly assigned to a peroxide-free strip, toothpaste and rinse routine (made with coconut, sage and lemon peel oils and Dead Sea salt) or to hydrogen peroxide strips with a regular fluoride toothpaste; 48 finished. After 14 daily uses, the peroxide-free group had no significant change in yellowness or lightness, while the peroxide group became measurably less yellow and lighter. Both were well tolerated. The study was run by the company that makes the peroxide strips, so it is not independent (Gurich et al., 2023).
- A lab study of two peroxide-free strips. On extracted teeth, the color change one week after treatment was 2.9 and 3.2 units for two peroxide-free strips, 2.5 for teeth soaked in water and 11.0 for a hydrogen peroxide strip. The peroxide-free strips did not differ from water (Cua et al., 2022).
- A 2026 lab study of four store-bought strips. Two of the three peroxide strips changed tooth color more than both the peroxide-free strip and untreated teeth. The authors judged the peroxide-free strip ineffective and concluded that peroxide-free products may not achieve clinically meaningful results (Hul et al., 2026).
The fourth, a lab study on cow teeth, tested a strip with a different peroxide-free ingredient, sodium dithionite, against a peroxide strip and reported that both improved color. Its summary gives no head-to-head numbers, and it was sponsored by a company and co-written by one of the authors of the 2025 review cited below (Newman et al., 2025).
Color change in these studies is measured with instruments, such as a spectrophotometer or digital photo analysis, or with a dentist’s shade guide, not by eye. Even teeth soaked in water shifted a little in the lab study above, which is why a comparison group matters (Cua et al., 2022). The Cochrane review of home whitening found that peroxide strips whiten teeth compared with a placebo over 2 weeks to 6 months, although the certainty of the evidence was low to very low (Eachempati et al., 2018).
What do peroxide-free strips use instead of peroxide?
“Peroxide-free” tells you what is missing, not what is doing the work. Check the ingredient list for one of these:
| Ingredient (what to look for on the label) | How it is meant to work | Best evidence so far |
|---|---|---|
| PAP (phthalimidoperoxycaproic acid) | Breaks down stain molecules without releasing hydrogen peroxide | Lab studies with mixed results; no long-term trials in people |
| Plant oils (coconut, sage, lemon peel) and salt | Loosen and lift surface stains | One trial in people found no significant whitening |
| Enzymes (bromelain from pineapple, papain from papaya) | Break down the protein film that holds stains | Lab studies only, some with color change close to a peroxide gel |
| Sodium chlorite or chlorine dioxide | Oxidize stains on the surface | Lab studies only; mostly surface stain removal |
| Sodium dithionite | A non-peroxide chemical that breaks down stains | One company-sponsored lab study |
| Violet (purple) pigment, “color correctors” | Tint teeth so they look less yellow | One short company-run trial (effect lasted at least the 60 minutes measured) and one lab study that found no effect |
The table summarizes the studies described in this article (Boruga et al., 2025; Chan & Cao, 2025; Gurich et al., 2023; Müller-Heupt et al., 2023; Newman et al., 2025; Palandi et al., 2026b; Pascolutti et al., 2024; Ribeiro et al., 2020).
The key difference is depth. Hydrogen peroxide and carbamide peroxide pass through enamel and break down colored molecules inside the tooth (ADA, 2022). When researchers stained teeth with coffee and then tested several over-the-counter whiteners, the peroxide-free agents at most removed the stain, while only hydrogen peroxide lightened the tooth beyond its natural color (Müller-Heupt et al., 2023).
Does PAP whitening work?
PAP is the peroxide-free whitener with the most research, and the results disagree. All of the studies below were done on extracted teeth, not in people:
- For PAP: A 2026 study found that a commercial PAP gel lightened teeth about as much as a 37.5% hydrogen peroxide office gel after three sessions, with fewer changes to the enamel surface (Llena et al., 2026). An earlier study by a PAP product maker reported better stain removal than 6% hydrogen peroxide (Pascolutti & de Oliveira, 2021).
- Against PAP: An over-the-counter PAP gel worn for 3 or 6 hours a day whitened teeth more than no treatment by day 14 but stopped improving after that, and stayed less effective than a 10% carbamide peroxide gel over 28 days (Jiménez-Díez et al., 2026). In another 2026 study, a PAP gel used with or without a whitening light for 7 days did no better than untreated teeth, while 10% hydrogen peroxide whitened them (Palandi et al., 2026a).
Formulas and treatment schedules differ, which may explain some of the gap: short, repeated applications in some studies against a week or more of daily use in others. A 2025 review concluded that the newer peroxide-free agents show promise in the lab, but clinical studies are essential to know whether they are safe and effective in real mouths (Chan & Cao, 2025). One of that review’s two authors lists a company affiliation.
Do purple whitening strips and serums work?
Purple products are color correctors. Violet is opposite yellow on the color wheel, so a thin purple film makes yellow teeth look whiter for a while. They don’t bleach the tooth.
- In a randomized trial of 60 adults, one 30-second application of a purple serum improved shade by about 3 shade-guide units right away, and the change lasted for the 60 minutes measured. A placebo did nothing. The trial was run by the product’s maker (Pascolutti et al., 2024).
- In an independent 2026 lab study, two color-corrector serums used after brushing did not differ from untreated teeth at any point, immediately or up to 7 days later, while a carbamide peroxide gel whitened the teeth (Palandi et al., 2026b).
- A 2025 systematic review of six studies (one clinical trial and five lab studies) found that peroxide-free color correctors produced less color change than carbamide peroxide, though still enough to be noticeable, with no enamel damage and rare sensitivity. Two of the six studies were by a product maker (Boruga et al., 2025).
In short, a purple product may help for an hour or so before a photo or an event (no one has measured how long the effect lasts beyond that), but it is a cosmetic tint, not whitening.
Are peroxide-free whitening strips safer for enamel and sensitivity?
In lab studies, peroxide-free products are gentle on enamel, but so are typical peroxide strips. Neither peroxide nor peroxide-free strips caused more enamel erosion than water in one study (Cua et al., 2022), and no strip damaged the enamel surface in another. In that study, hydrogen peroxide from two peroxide strips reached the inner chamber of the tooth, at lower levels than from a 6% peroxide gel, while none was found with the peroxide-free strip (Hul et al., 2026). PAP gels showed no enamel damage in several lab studies (Jiménez-Díez et al., 2026; Müller-Heupt et al., 2023; Palandi et al., 2026a).
Peroxide-free does not mean risk-free. An earlier lab study, cited by Müller-Heupt et al. (2023), found that some sodium chlorite and PAP formulas reduced enamel hardness, possibly because they were acidic. In cell tests in the same study, bromelain was the only agent, peroxide or not, that was not toxic to human cells (Müller-Heupt et al., 2023). In a lab model of 9 months of use, whitening rinses with hydrogen peroxide or chlorine dioxide used before brushing increased enamel wear compared with brushing alone (Torres et al., 2018).
Peroxide side effects are real but usually short-lived. Sensitivity can affect up to two-thirds of people using strips or trays and usually starts within 2 to 3 days (ADA, 2022). Across 71 trials, sensitivity and gum irritation were the most common side effects, more frequent with stronger products, and mild and temporary (Eachempati et al., 2018). If sensitivity is your worry, see whether sensitive toothpaste before whitening helps.
How can you tell if a whitening claim is backed by evidence?
The October 2026 ruling is a useful lesson. The watchdog rejected two of the company’s new studies because they had no negative control, a group that gets no active treatment, so any whitening could not be credited to the strips. It rejected the third, a randomized, double-blind, placebo-controlled study, because some of its color measurements “should have been impossible” (BBB National Programs, 2026). In the original case, the watchdog had found that the company did have support for its claim that the strips whiten without sensitivity (BBB National Programs, 2026).
When you read a whitening claim, look for:
- A comparison group. A placebo or untreated group shows whether the product did anything at all (BBB National Programs, 2026).
- Studies in people, not only extracted teeth. Most peroxide-free evidence is lab work (Chan & Cao, 2025).
- Who ran the study. Several key studies were run by companies with a commercial stake: a competitor in one case (Gurich et al., 2023) and the product’s own maker in another (Pascolutti et al., 2024).
- How long the result lasts. A tint measured over one hour is not the same as bleaching (Pascolutti et al., 2024).
- The ADA Seal of Acceptance. Over-the-counter strips and toothpastes can earn it; dentist-supplied products are not eligible (ADA, 2022).
What works if you want whiter teeth?
Peroxide products are the ones with evidence in people. Dentist-supervised trays, in-office whitening and peroxide strips all whiten, with sensitivity as the main trade-off (ADA, 2022; Eachempati et al., 2018). Our guide to whether teeth whitening is safe and what works compares the options and who should avoid whitening.
If your teeth are mostly stained on the surface from coffee, tea or wine, a whitening toothpaste can help remove those stains, though it doesn’t change the color of the tooth itself. See does whitening toothpaste work? for the evidence, and is charcoal toothpaste safe? before you try a charcoal product. Coconut oil and other home remedies have little evidence behind them (ADA, 2022).
What it means for you
If you already bought peroxide-free strips
They are unlikely to hurt your enamel based on lab studies, but expect little or no change in tooth color (Cua et al., 2022; Gurich et al., 2023; Hul et al., 2026). If you see no difference after a full course, a peroxide product or a talk with your dentist is the next step.
If peroxide whitening made your teeth sensitive before
Sensitivity is common and usually short-lived (ADA, 2022), and weaker products tend to cause less of it (Eachempati et al., 2018). Ask your dentist about a lower-strength product, and see why teeth get sensitive and what helps.
If you want whiter teeth for an event this week
A purple color corrector may make teeth look whiter for at least an hour, the time measured in one trial (Pascolutti et al., 2024). Real whitening takes days to weeks. After any whitening, see how long to wait before drinking coffee.
If you are pregnant, breastfeeding or under 18
We found no study that tested whitening strips of any kind during pregnancy or breastfeeding. Whitening is cosmetic and can wait, so ask your dentist first. The American Academy of Pediatric Dentistry discourages cosmetic whitening of the whole smile for children and teens who still have baby teeth (ADA, 2022).
Questions to ask your dentist
- Are my teeth stained on the surface, or is the color inside the tooth?
- Would peroxide whitening work on my teeth, and which strength suits me?
- Do I have crowns, veneers or fillings on my front teeth that won’t change color (ADA, 2022)?
- Is it safe to whiten with my current sensitivity, gum health or fillings?
- Which over-the-counter products would you suggest, if any?
When to see a dentist
Book a dental visit if:
- One tooth is darker than the others. A single dark tooth needs a check, not a whitening product.
- Your teeth stay sensitive for more than a few days after any whitening product (ADA, 2022).
- Your gums stay sore or irritated after using a strip or gel (Eachempati et al., 2018).
- You have crowns, veneers or fillings on your front teeth and want to whiten (ADA, 2022).
- You want whitening and haven’t had a check-up in a while, so cavities or gum problems can be treated first.
If you have severe tooth pain, swelling or a fever, see what to do in a dental emergency.
The bottom line
Peroxide-free whitening strips are gentle in lab tests, but most studies so far show little or no whitening: no significant change in the one trial in people, and no more than water or no meaningful change in two of three lab studies. PAP has mixed lab results and no long-term trials in people, and purple color correctors only tint teeth for a short time. If you want teeth that are actually lighter, peroxide products, ideally with your dentist’s advice, are the ones with evidence, and their usual side effect, sensitivity, tends to be mild and temporary.
References
American Dental Association. (2022). Whitening. ADA Library & Archives, Oral Health Topics. https://www.ada.org/resources/ada-library/oral-health-topics/whitening
BBB National Programs. (2026, October 22). National Advertising Division recommends Oral Essentials discontinue “30 minutes to whiter teeth” claim for Lumineux Whitening Strips [Press release]. GlobeNewswire. https://finance.yahoo.com/media-advertising/articles/national-advertising-division-recommends-oral-152000162.html
Boruga M, Tapalaga G, Luca MM, Bumbu BA. (2025). Hydrogen peroxide-free color correctors for tooth whitening in adolescents and young adults: A systematic review of in vitro and clinical evidence. Dentistry Journal, 13(8), 346. https://doi.org/10.3390/dj13080346
Chan DCN, Cao D. (2025). Updates on non-peroxide dental bleaching agents. American Journal of Dentistry, 38(Spec No A), 32A–37A. https://pubmed.ncbi.nlm.nih.gov/41183142/
Cua J, Crespo E, Phelps S, Ramirez R, Roque-Torres G, Oyoyo U, Kwon SR. (2022). Tooth color change and erosion: Hydrogen peroxide versus non-peroxide whitening strips. Operative Dentistry, 47(3), 301–308. https://doi.org/10.2341/20-302-L
Eachempati P, Kumbargere Nagraj S, Kiran Kumar Krishanappa S, Gupta P, Yaylali IE. (2018). Home-based chemically-induced whitening (bleaching) of teeth in adults. Cochrane Database of Systematic Reviews, 2018(12), CD006202. https://doi.org/10.1002/14651858.CD006202.pub2
Gurich N, Anastasia MK, Grender J, Sagel P. (2023). Tooth color change and tolerability evaluation of a hydrogen peroxide whitening strip compared to a strip, paste, and rinse regimen containing plant-based oils and Dead Sea salt. American Journal of Dentistry, 36(3), 151–155. https://pubmed.ncbi.nlm.nih.gov/37364193/
Hul EA, Favoreto MW, Barbosa LMM, Cordeiro DCF, Centenaro GG, Borges CPF, Reis A, Loguercio AD. (2026). Over-the-counter whitening strips: Evaluation of color change and hydrogen peroxide penetration into a pulp chamber. Journal of Dentistry, 167, 106544. https://doi.org/10.1016/j.jdent.2026.106544
Jiménez-Díez D, Carneiro TS, Monzón C, Barbosa LMM, Favoreto MW, Loguercio AD, Fuentes V, Ceballos L. (2026). Efficacy, pH, and enamel effects of an over-the-counter non-hydrogen peroxide gel for at-home tooth bleaching. Journal of Dentistry, 171, 106718. https://doi.org/10.1016/j.jdent.2026.106718
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Newman J, Youn T, Suk M, Dong C, Lu J, Sample M, Yang I, Chan DCN. (2025). Assessments of a novel bleaching agent containing sodium dithionite: A laboratory study. American Journal of Dentistry, 38(Spec No A), 38A–43A. https://pubmed.ncbi.nlm.nih.gov/41183143/
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Palandi SS, Kim NH, Queiroz MVGB, Kury M, Cavalli V. (2026b). Are the so-called color corrector serums effective for immediate dental colorimetric changes? An in vitro study. Journal of Dentistry, 176, 106981. https://doi.org/10.1016/j.jdent.2026.106981
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Pascolutti M, Tomic A, Milleman KR, Milleman JL, Walsh LJ. (2024). Safety and effectiveness of a novel color corrector serum for causing temporary changes to tooth shade: A randomized controlled clinical study. Dentistry Journal, 12(7), 197. https://doi.org/10.3390/dj12070197
Ribeiro JS, Barboza ADS, Cuevas-Suárez CE, da Silva AF, Piva E, Lund RG. (2020). Novel in-office peroxide-free tooth-whitening gels: Bleaching effectiveness, enamel surface alterations, and cell viability. Scientific Reports, 10(1), 10016. https://doi.org/10.1038/s41598-020-66733-z
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References checked October 2026 · Editorial policy · Report a correction
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