Ingredient Beauty BenefitsOther · An ingredient class — not a single line on an ingredient list
Aluminium salts: the oldest antiperspirant ingredient there is — and we found no placebo-controlled trial
In a 50-person randomised trial, aluminium chloride and aluminium lactate reduced axillary and inguinal sweating comparably, and the lactate had better tolerability. But both arms received an aluminium salt, and there was no arm applying nothing. What botulinum toxin and microwave have under the same sweating concern is missing here.
Last checked Sep 19, 2026
- In pregnancy
- Not established
- Irritation
- Moderate
- Daytime use
- ✓ Fine
Not a measurement — reported irritation grouped into five steps. It varies between people.
Aluminium salts are the main active in deodorants and antiperspirants. On an ingredient list they appear under individual names: aluminium chloride, aluminium chlorohydrate, aluminium sesquichlorohydrate, aluminium lactate.
This site treats them as a class rather than a single ingredient for the same reason as the sunscreen and fragrance allergens pages — the evidence attaches not to one raw material but to the act of applying an aluminium salt.
The mechanism given is forming a plug at the mouth of the sweat duct. Aluminium ions gel in sweat and temporarily block the duct, so this does not reduce sweat production but blocks the way out. In that it differs from botulinum toxin.
And the most striking thing on this page is what is missing.
Deodorant is probably used daily by more people than any other ingredient on this site. And yet we found no randomised trial comparing it against placebo.
Contents
What is established
The same ingredient at a different strength, in a different formula, is a different product. These are the conditions the studies used.
Two kinds of aluminium salt worked comparably, and the lactate irritated less
A 2022 trial in Germany. The authors describe it as the first randomised controlled trial of a lactate-based antiperspirant.
- Fifty healthy participants with excessive perspiration in the axillae and the groin
- Open-label, randomised, controlled
- An aluminium chloride-based antiperspirant against an aluminium lactate-based one
- Assessed by four physiological parameters — pH, transepidermal water loss (TEWL), gravimetric analysis and the Minor test (iodine-starch) — plus two questionnaires: DLQI (Dermatology Life Quality Index) and HDSS (Hyperhidrosis Disease Severity Scale)
- Tolerability was evaluated via symptom diaries
Looking at the groin as well is what makes this trial valuable. As the authors note, aluminium salts have long been used in the underarm, but less is known about their anhidrotic potential in the groin.
The results.
- Both preparations were comparably effective in reducing axillary and inguinal perspiration, and grew more effective over time
- In both regions, the aluminium lactate antiperspirant had a more favourable tolerability profile
- The authors conclude that, given comparable efficacy and superior tolerability most noticeably in the groin, the evidence supports aluminium lactate as a first-line option
Three things to read carefully.
One, it was open-label. Participants and investigators both knew which preparation was which. Instrument readings such as gravimetry wobble less, but DLQI and HDSS are self-answered, so expectation enters.
Two, 'comparably effective' may also mean neither was outstanding. It is the problem we write about repeatedly on the procedure pages — when A versus B shows no difference, you cannot tell whether both were good or both were mediocre. The third item below is about that.
Three, the tolerability difference is clear practical information. The most common reason people stop using an antiperspirant is stinging and itching. If two things work the same and one irritates less, that alone is a reason to choose.
- Randomised controlled trial in people · 50 participants · Compared with another active ingredient · Funding not declared · Endpoint instrument measurement PMID 36495093
In the iontophoresis trial, the untreated hand improved just as much
A 2023 trial in Iran. It examined driving the aluminium salt in with current rather than applying it, and the same trial appears on this site's iontophoresis page.
- Thirty-two patients with primary palmar hyperhidrosis, in two groups of sixteen
- Aluminium chloride hexahydrate gel iontophoresis against tap water iontophoresis
- On the dominant hand only, seven sessions every other day
- Sweating rate measured by gravimetry and the iodine-starch test
The results.
- Sweating fell significantly in both hands in both groups (P < .001)
- But there was no significant difference between the treated hand and the untreated one
How to read that on this page.
The aluminium chloride gel was not better than tap water. And the hand that had aluminium chloride driven into it was not better than the untreated hand on the other side.
But this must not be carried over as 'aluminium salts do not work'. What the trial used was delivery by iontophoresis, not application to the underarm. That a different route needs its own evidence is something this site writes repeatedly, on the collagen and l-carnitine pages.
The reason it is recorded here is one: it is the only trial we found on aluminium salts that contains a comparison against a side receiving nothing. In that comparison, the aluminium salt did not win.
Why that hand improved too is set out in detail on the iontophoresis page.
- Randomised controlled trial in people · 32 participants · 2 weeks · Compared with another active ingredient · Funding not declared · Endpoint instrument measurement PMID 37436009
We found no placebo-controlled trial
We found no randomised trial comparing an aluminium salt antiperspirant against the same base without the aluminium.
This gap is notable for a reason.
Under the same sweating concern sit the thickest evidence bases on this site.
- Botulinum toxin — 322 people, 52 weeks, placebo-controlled, 75% against 25%
- Microwave — sham-controlled, 89% against 54%
And the oldest and most widely used option, the aluminium salt, has none of that.
The reason is guessable. In most countries deodorants are cosmetics or quasi-drugs, so they are not asked for the kind of trials a new drug must file. And since the effect has been known for so long, there is little incentive to design a fresh placebo-controlled trial.
Even so, this site does not count 'it has been used for a long time' as evidence. The cryolipolysis page carries the same sentence.
A 2025 study compared aluminium chloride, oxybutynin and botulinum toxin. We keep it in this item's sources as a piece that weighs three options in one place, but we have not verified its results at source, so we do not carry its content over here.
Separating what is and is not established:
- Aluminium chloride and aluminium lactate worked comparably — established
- The lactate irritated less — established
- Whether an aluminium salt beats applying nothing — not established
- What concentration is appropriate — not established
How to use it
- The trials above do not state concentrations in their abstracts. We do not invent numbers.
- In the trial above, effectiveness increased over time. It is hard to judge from one or two uses.
- In both regions, the aluminium lactate was better tolerated. If stinging made you stop, switching the type of salt is an option.
- An antiperspirant and a deodorant are different products. A deodorant addresses smell; an antiperspirant addresses sweat. Checking the ingredient list for an aluminium salt tells you which is which.
- If severity is high, this ingredient alone may not settle it. The sweating page sets out the other options.
Cautions
- Stinging, itching and redness are common. In the trial above, this is what separated the two preparations.
- Applying it right after shaving, or onto broken skin, increases irritation.
- A link between aluminium and breast cancer or Alzheimer's disease has long been claimed. We have not verified source material that can answer that question, so this page says nothing either way.
- We found no established data on use during pregnancy.
- We could not verify from the abstracts the full range and frequency of adverse events reported.
With a new ingredient, apply a small amount somewhere inconspicuous, such as the inner arm, for two days first. Stop if it reddens or stings.
Related skin concerns
What this article relies on
- PubMed — 미국 국립의학도서관 문헌 데이터베이스National Library of Medicine · Checked on 2026-09-16