The Sensodyne range decoded: which variant uses which active, from the published ingredients.

Three chemically unrelated actives are sold under one brand name, and the ingredient list on the back of the tube is the only reliable way to tell which one you are holding: calcium sodium phosphosilicate, stannous fluoride or potassium nitrate. Of the eight variants whose ingredient lists were read at Boots in September 2026, four publish how much of that active they contain and four do not, and whether the paste lists water at all separates the potassium nitrate tubes from the rest. The row for S3 Sensitivity Science™ in the same review declares 5% potassium nitrate, nano- and biomimetic hydroxyapatite at inclusion levels as supplied, and 1450 ppm fluoride as sodium monofluorophosphate.

What was checked22 peer-reviewed studies, product information as published by each brand, and guidance from the Oral Health Foundation and the NHS

Which active is in which Sensodyne, and how do you tell?

By reading the ingredient list, because the front of the pack does not tell you. The rows below come from the ingredient panels published on the Boots product pages and read on 2026-09-09, each with its record in our category review of UK sensitivity toothpastes, and the stated-action column is the brand's own wording from its own site, read on 2026-09-10. The last row is S3, at the price its own site showed on the same day. This page compares ingredients and stated actions only, not clinical performance, based on what each brand states about its own formula. Prices and formulations may change; always check the pack.

Three reading notes before anyone acts on that table. The brand's own UK site publishes product descriptions without ingredient panels, so a retailer's listing is where the ingredients were read; the brand's site is quoted only for what the brand says an active does. The Corsodyl row is there for one reason: it is the same declared stannous fluoride level under a different Haleon brand, with a zinc salt added, which is a useful reminder that an active is not owned by the name on the front. And the rows run in order of price, not of preference, because ranking them any other way would be a judgement this page has no evidence for.

What does each of the three actives actually do?

Two of them cover the tubule and one of them works on the nerve, and that division is the whole guide. A 2013 review of the field, whose lead author was employed at the time by a consumer-health manufacturer, sorts desensitising actives into exactly those two classes: potassium salts are the nerve-directed group, and bioglasses, strontium salts, oxalates and arginine with calcium carbonate are the occluding group³. Potassium calms the nerve; hydroxyapatite of the size S3 uses works inside the tubule and on the surface; each does a job the others cannot.

Potassium nitrate is the nerve active, and its mechanism remains a proposal, not a finding. The working model is that potassium ions travel down the open tubules, raise the potassium concentration around the nerve endings and leave them less ready to fire; a review of 27 clinical trials states plainly that this has never been confirmed in an intact human tooth⁴. All sixteen double-blind randomised trials of potassium toothpastes that the same review found reported significant reductions, which is a strong record for the ingredient and no proof at all of the mechanism behind it⁴.

Calcium sodium phosphosilicate is a bioactive glass, inert while dry and reactive as soon as it meets saliva. In a randomised exploratory study run by scientists at the manufacturer, brushing with the glass raised dissolved silicon in people's saliva, and calcium for the first quarter of an hour, so the ion release is measurable in a mouth and not just in a beaker⁵. What the ions then do has been photographed rather than felt: in laboratory work part-authored by the maker, serial block-face electron microscopy showed the glass paste occluding more surface tubules than a stannous fluoride paste and raising the mineral density of the dentine it was brushed onto⁶. Sensodyne states, on its own ingredients page, that its NovaMin "builds a repairing layer over the vulnerable areas of your teeth and helps protect them from pain".

Stannous fluoride is the third route, and the brand describes it the same way: on the same page, Sensodyne states that its stannous fluoride toothpastes "work like a shield to protect the exposed inner part of the tooth called dentine". The tin deposits over exposed dentine and into the tubule openings while the fluoride does the ordinary job fluoride does. It is worth saying where that whole class of evidence sits. A systematic review of 35 laboratory studies found bioactive glass and hydroxyapatite both occlude tubules against control, and found no clinical occlusion studies at all to include⁷. Occlusion is a picture of a tooth surface, not a measurement of anyone's pain, and every occlusion figure on this page should be read that way.

One gap in the sourcing is worth stating rather than hiding. The brand's own ingredients page, read on 2026-09-10, names and explains stannous fluoride and NovaMin and does not name potassium nitrate, which is why the stated-action wording for the potassium tubes in the table above comes from those products' own pages instead.

Which variants publish how much of their active they contain?

Four of the eight do, and four do not, and the four that do not are not hiding a small number: they are publishing nothing. Pronamel Daily Protection prints potassium nitrate at 5% w/w, Clinical Repair Active White prints its glass at 5% w/w, and Sensodyne Rapid Relief and Sensitivity & Gum both print stannous fluoride at 0.454% w/w. The two Repair & Protect listings name the glass with no level, and Daily Care and Complete Protection+ name potassium nitrate with no level. "Not declared" in that column means not published on the page that was read. It is not a claim that the amount is low, and nothing on this page should be read as one.

The reason a reader wants that column is the assumption underneath it, which is that a printed percentage works like a strength rating. Nobody has shown that it does. A PubMed search run for this page in September 2026, for dentine hypersensitivity together with dentifrice or toothpaste and dose, concentration or dose-response, returned thirty-two records, and not one of them compares two concentrations of the same desensitising active in a toothpaste in people. The nearest thing in the literature is indirect and it points the other way: an independent appraisal in an evidence-based dentistry journal, of a systematic review and meta-analysis of eleven randomised trials of the glass, notes that 7.5% beat the negative control where 2.5% did not⁸. Across trials, then, concentration can matter within an ingredient. Between two tubes on a shelf, with different bases, different abrasives and different actives, a printed percentage is a fact about disclosure and not a strength rating.

That is the honest reading of the disclosure column, and it cuts against the page's own side as much as anyone's. Pronamel Daily Protection publishes potassium nitrate at 5% w/w, which is the same dose S3 declares and the same dose the placebo-controlled toothpaste trials used, for £5.50 for 75 ml. On the nerve active, the market leader's own enamel variant matches S3's declared level, and its ingredient list is where you can check it.

Why do some of these pastes contain no water?

Because a bioactive glass that meets water in the tube starts reacting before it reaches the mouth. In the recorded rows the pattern is clean: the three potassium nitrate variants list Aqua and the three glass variants and the two stannous fluoride variants do not. Water is what lets S3 carry potassium nitrate alongside hydroxyapatite in one paste, and an anhydrous formula built around bioactive glass cannot do that.

Two honest limits on that paragraph. No published paper states the water-and-glass incompatibility in those words. It is formulation chemistry read against ingredient lists anyone can check, which is not the same thing as a published measurement and not the same thing as an assertion. And the pattern does not extend to stannous fluoride: pastes carrying potassium and stannous fluoride together exist and have been pooled in meta-analyses¹⁸, so the absence of water in the two stannous rows is a formulation choice rather than a chemical necessity.

What the water column is good for is a ten-second check at home. If the list on your tube starts with water or names Aqua high up, you are almost certainly on the potassium nitrate side of this range; if it starts with glycerin and PEG, you are on the occluding side. That is a fact about your own tube, arrived at without trusting anybody's marketing, and it is the most useful thing on this page.

What does the published evidence show for each active, and how sure is it?

That all three actives have published evidence behind them, that the syntheses disagree with each other, and that the certainty attached to each result matters as much as its size. The table below reports what the pooled analyses found, with the certainty as the reviewers themselves graded it, and with the funding declared where the source declares one. Hydroxyapatite is in the table although no variant of this range contains it, so that S3's own actives are judged by the same evidence as the range's.

Start with the disagreement, because averaging it away would be dishonest. In a 2020 systematic review and network meta-analysis of 125 randomised trials and 12,541 patients, calcium sodium phosphosilicate was the most beneficial formulation across all three stimuli, with high to moderate certainty². In a 2026 systematic review and network meta-analysis of 93 randomised trials and 9,548 participants, the same active scored −0.36 on the two-week cold-air scale with a credible interval running from −0.74 to 0.01 and low confidence, while stannous fluoride scored −0.85 on ten studies with high confidence and nano-hydroxyapatite −0.96 on two studies with moderate confidence¹. Six years, two teams, two different pictures of the same shelf. The 2026 authors' own conclusion is the fairest sentence available on the subject, and it is not ours: choice should be guided by preference, tolerability and availability rather than an expectation of superior efficacy¹.

Potassium nitrate has the longest record and the most awkward one. The 2006 Cochrane review of six randomised trials found it reduced air-blast and tactile sensitivity at six to eight weeks and had no significant effect on what patients said about their own teeth, and concluded there is no clear evidence to support potassium toothpastes⁹; the 2001 Cochrane review of eight trials had already put it as "no strong evidence"¹⁰. Set against that, a 2015 systematic review and meta-analysis of 31 randomised trials found potassium toothpastes beat placebo, with a standardised mean difference of −1.28 and heterogeneity between the trials high enough that the caveat deserves more attention than the figure¹⁸. A 2018 systematic review and meta-analysis of 53 randomised trials in 4,796 patients put potassium above a toothpaste with no active at all, in its low-quality evidence band¹⁷. A 2019 network meta-analysis of 30 randomised trials found no significant difference between potassium and placebo, and measured a large placebo effect in the process¹⁶.

The two direct comparisons that matter to this range both favour the glass in the early weeks. A 2018 systematic review and meta-analysis of eight randomised trials in 411 patients found a calcium sodium phosphosilicate dentifrice ahead of a potassium nitrate dentifrice on air blast at two, four, six and eight weeks, and no longer ahead at twelve; neither separated from the other at one week¹¹. Heterogeneity in that pooling ran as high as 98%, and its authors call the trial base small¹¹. In a 12-week double-blind randomised trial of 120 adults, the glass was significantly ahead of potassium nitrate at two and four weeks — reductions in air-blast pain of 45% against 35% at two weeks — and all three actives had converged by twelve¹².

Timing is the practical part of all this. A 2019 systematic review of 74 randomised trials and 5,366 patients grouped treatments by when their effect reached significance and found that only in-office treatments act within a week, placing hydroxyapatite and stannous fluoride in the medium-term group and potassium nitrate in the long-term one²¹. In a double-blind randomised trial of 120 adults funded by the maker of one of the test pastes, potassium nitrate had not separated from the control on the tactile probe at day three, while stannous fluoride had¹³. In a separate examiner-blind randomised trial of 215 completers, funded and authored by the maker of the paste it tested, the 5% glass was ahead of a plain fluoride paste from day three and kept improving to eight weeks¹⁴. The manufacturer-archive meta-analysis of 14 randomised trials and 1,287 participants that gives stannous fluoride its 22% advantage over potassium nitrate or arginine controls comes from the sponsor's own archive and was written in part by its employees¹⁵.

Two things this table cannot do. It cannot tell you how much of any of these results is the response to being treated at all: in a six-month randomised placebo-controlled crossover trial in 35 patients of a professionally applied paste, the water placebo alone cut air-blast pain by 20% at once and by 36% at six months²². And it cannot compare finished products. Every row is an ingredient class, pooled across formulations with different bases and abrasives, which is exactly why the level printed on a tube is not a ranking.

What do they cost, per tube and per millilitre?

Between £2.55 and £6.00, and the spread has nothing to do with the active. Every competitor row on the table above is a 75 ml tube, so no conversion was needed and the prices are already comparable: £3.40 per 100 ml for the cheapest, £8.00 per 100 ml for the dearest. The cheapest tube in the range carries potassium nitrate with no level published, and the dearest carries the glass at a level it prints; both carry the same 1450 ppm fluoride, as does everything between them. A tube priced at double another in the same range is not, on this evidence, double anything.

The awkward cell is ours. S3 is £14.99 as shown, reduced from £19.99, and its product page publishes no tube volume anywhere, so the per-75 ml figure every other row carries cannot be computed for it. Rather than estimate one, the table says so. Prices and formulations may change; always check the pack.

Which variant addresses both the nerve and the tubules, and where does S3 sit?

None of them, on the published lists, and that is a statement about chemistry, not about the brand. Read the active column again: the potassium tubes work on the nerve and the glass and stannous tubes work on the tubule, and a tube carrying a nerve active and a fluoride salt is a real and reasonable formula that a great many people do well on. Hydroxyapatite occludes, potassium desensitises, and neither does the other's job, which is the argument for carrying both.

What that argument does not have is a trial of the finished thing. In the 2020 network the potassium-plus-hydroxyapatite node sits among the largest estimates on the tactile and air stimuli, and the review's own appendix shows that node resting on two randomised trials and 140 patients, against twelve trials and 1,724 patients for stannous fluoride². The 2026 network meta-analysis does not carry the combination as a node at all¹. Where the two actives have been compared directly rather than combined, a four-week randomised trial in 39 adults found a hydroxyapatite toothpaste relieved air-blast sensitivity as well as a potassium nitrate toothpaste, with no difference between them and no negative control to anchor either¹⁹. In an eight-week double-blind randomised trial of 85 adults, funded by the maker of the test pastes, nano-hydroxyapatite toothpastes with and without added potassium nitrate were as effective as the glass²⁰. The ingredients in S3 rest on more than 90 verified published studies of that sort, which is a statement about the ingredients and not about the tube.

So the honest placement is narrow. S3 is the row on this table that carries a nerve active and an occluder together, at levels it publishes with their basis, in a water-based paste that keeps full adult-strength fluoride. No trial has tested any of these finished products against it, and none has tested its own combination as a product. If you have never tried an occluder and want the cheapest way to find out whether occlusion is your answer, the table above names tubes at a fifth of the price, and the ingredient list is how you check what you are buying.

What does this table not cover?

Most of the range, and the number is worth printing. Counted as distinct product-page links in the brand's own UK product navigation on 2026-09-10, the range runs to 36 products: 32 toothpastes, two mouthwashes and two toothbrushes, and this page decodes eight of those 32. Sensodyne Cavity + Sensitivity, Sensitivity Gum & Enamel, Sensodyne Clinical Repair Deep Clean, the Advanced White and Clinical White pastes, the Daily Care whitening and deep-clean variants and every Pronamel beyond Daily Protection are not in the table, and a variant missing from the table is one nobody here has read, not one with no active. The rest of the UK sensitivity shelf, brand by brand, is in the category review this page draws its rows from.

The table also cannot tell you whether a toothpaste is the right answer at all. The Oral Health Foundation names potassium citrate, potassium nitrate and stannous fluoride as the actives to look for and names neither the bioactive glass nor hydroxyapatite, which is a limit on two of the four rows above and on two of S3's three actives²³. It says to keep using a sensitivity toothpaste to maintain the effect, and to see a dentist if the pain is severe, if it lasts more than a few weeks, if only one tooth is affected or if it came on suddenly²³. The NHS puts a shorter fuse on pain that is not sensitivity: toothache lasting more than two days is a dentist's appointment, not a shopping decision²⁴. The Journal's ingredient comparison with Repair & Protect reads one pair of tubes in that light, and the Journal piece on how sensitive toothpastes work and why yours might not be working covers what to do when the tube you have is not helping.

Frequently asked questions

Which Sensodyne variants contain potassium nitrate?

On the lists read in September 2026, three of the eight: Pronamel Daily Protection at 5% w/w, and Daily Care and Complete Protection+ with no level published. All three are water-based and carry sodium fluoride at 1450 ppm, and they are the only variants in the table that act on the nerve rather than the tubule.

Is Pronamel a sensitivity toothpaste?

By ingredient, yes: the Boots list declares potassium nitrate at 5% w/w, the nerve-calming active, at the concentration the placebo-controlled trials used. The brand's own page for it leads on acid erosion and enamel and also states that it will "provide lasting sensitivity care". Both of those are what each page says; the ingredient list is the part you can check on the tube.

Does a higher declared percentage mean a stronger toothpaste?

There is no published evidence that it does. A PubMed search run for this page in September 2026 returned thirty-two records on dose and concentration in dentine hypersensitivity, and none of them compares two concentrations of the same desensitising active in a toothpaste. Within one ingredient, concentration can matter — an independent appraisal of a systematic review and meta-analysis of eleven randomised trials noted 7.5% of the glass beating a negative control where 2.5% did not⁸ — but between two different tubes with different bases, a printed percentage tells you the maker published a number, not that the tube is stronger.

Why is there no water in some of these pastes?

Because a bioactive glass reacts with water, so a paste built around it uses a glycerin and PEG base instead. In the rows recorded here the two stannous fluoride variants are also water-free, which is a formulation choice rather than a necessity: pastes combining potassium and stannous fluoride exist and have been pooled in meta-analyses¹⁸. If the list on your tube names Aqua near the top, the active in it is almost certainly potassium nitrate.

Does any Sensodyne variant do what S3 does?

Not on the published lists. No variant in this range carries a nerve active and hydroxyapatite in the same tube; several carry a nerve active and fluoride, which is a real and reasonable formula and is what a great many people use. S3 carries potassium nitrate, two forms of hydroxyapatite and 1450 ppm fluoride as sodium monofluorophosphate, at levels published with their basis. Nobody has tested either finished product against the other, so the comparison stops at the ingredient list.