At a Glance

• Both aluminum chlorohydrate and aluminum sesquichlorohydrate are FDA-approved antiperspirant active ingredients that work by forming temporary gel plugs inside sweat ducts
• Aluminum chlorohydrate (ACH) is the industry workhorse — cost effective, easy to formulate, and approved globally for cosmetic and personal care use
• Aluminum sesquichlorohydrate (ASCH) offers superior sweat suppression and better skin tolerance, making it the go-to for clinical-strength and premium aluminum sesquichlorohydrate deodorant formulations
• Aluminum zirconium tetrachlorohydrex gly is the strongest OTC option, roughly 34% more effective than aluminum chloride, but comes with higher cost and tighter regulatory limits (max 20% concentration vs 25% for ACH and ASCH)
• Current research does not support the claimed links between aluminum-based antiperspirants and breast cancer or Alzheimer’s disease
• The aluminum-free deodorant segment is growing at about 10% CAGR, but aluminum-based antiperspirants still dominate the $34+ billion global market because aluminum-free products cannot actually stop sweating
• MoCRA is changing documentation requirements for US antiperspirant manufacturers, with fragrance allergen labeling rules expected in 2026

If you’re formulating antiperspirants or looking for active ingredients to supply to a personal care company, whether you choose aluminium sesquichlorohydrate vs aluminum chlorohydrate is not a minor decision. It impacts the effectiveness of your product, its sensory properties, labelling claims, and your product’s market positioning.

Both ingredients perform the same function as they plug sweat glands by creating a gel plug in the eccrine ducts and so decrease the amount of sweat that reaches the skin. But they do it differently, so you can have a product that is not liked by consumers if you’re not selecting the right ingredient for the right application.

The worldwide market for deodorant and antiperspirant ingredients was valued at USD 34.6 billion in 2024, and is expected to grow to USD 51.5 billion by 2032. And in this, the issue of aluminum salts is getting more nuanced. Consumers are more informed, regulators are tougher and formulators need to have a better understanding of ingredients.

How Aluminum Antiperspirants Work

Let’s first take a look at the mode of action for antiperspirants containing aluminum, before we get into the nitty-gritty of individual ingredients.

After all, when you apply antiperspirant containing aluminum chlorohydrate or antiperspirant containing aluminum sesquichlorohydrate, the active ingredient, aluminum ions bind with the electrolyte in your sweat. This produces a gel that blocks the opening of the sweat duct. This plug is temporary, and is broken down over time, which requires reapplication.

The FDA approves 18 different active ingredients that contain aluminum for use in OTC antiperspirants. The most common ones are:

• Aluminum Chlorohydrate (ACH) – most common, up to 25%
• Aluminum Sesquichlorohydrate (ASCH) – more effective, also capped at 25%
• Aluminum Zirconium Tetrachlorohydrex Gly – the most effective OTC, allowed up to 20%
• Aluminum Chloride – the simplest and most acidic salt, also prescription only

Each has its own strengths. Which one you choose depends on the product you want to make and for what audience.

Aluminum Chlorohydrate: The Go-To

Aluminum chlorohydrate is the mainstay of commercial antiperspirants. It’s cheap, effective and compatible with a variety of formulation bases, so you’ll find it in everything from pharmacy roll-ons to spray cans.

How It Works

ACH’s general formula is Al_nCl_(3n-m)(OH)_m. It has a low molecular weight and particle size, which allow it to be absorbed and dry rapidly on the skin. It produces a stable gel with sweat that forms the plug that blocks the channels and limits sweating.

The pH is relatively neutral (unlike aluminum chloride, which is very acidic and can burn). This broader pH tolerance profile means that ACH can be used with most preservatives, fragrances and excipients without significant formulation changes.

Why Formulators Use It

• Cost effective in mass production. Synthesis of ACH is cheap, it’s available in various grades, and is suitable for low and medium price-point products
• Works in almost all product forms. Readily incorporated into roll-ons, sticks, gels, aerosols, creams – no special manufacturing necessary
• Regulatory simplicity. Cleared by the FDA, Health Canada, European Commission, and the majority of the rest of the world. Documentation requirements are straightforward
• Minimal pH sensitivity. ACH doesn’t need to be formulated at a specific pH for stability or skin tolerability, as is the case with aluminum chloride

Where It Falls Short

ACH is good for normal levels of sweating. But it doesn’t have sufficient blocking properties for people who sweat excessively, such as those with hyperhidrosis. In those cases, you have to switch to the more effective aluminum sesquichlorohydrate or aluminum zirconium tetrachlorohydrex.

There’s also a skin sensitivity limit. It’s not a problem for most, but regular shaving with sensitive skin can cause irritation with extended use. It’s not a deal-killer for most, but it is for brands going after sensitive skin.

Aluminium Sesquichlorohydrate: The Gold Standard

Aluminium sesquichlorohydrate has found a niche in clinical-strength and dermatologist-recommended products. If ACH is the family car, ASCH is the sports model – both are from the same line, but ASCH has more power.

The Molecular Advantage

ASCH is a cousin of ACH with a greater ratio of aluminum to chloride, and a more complicated molecular structure. This may seem like a bit of chemical trivia, but it actually affects its efficacy.

ASCH’s higher molecular weight results in stronger, more resistant gel plugs in the sweat glands. These plugs:

• Have a longer lifespan (24-48 hours of coverage)
• Cover a larger duct surface area
• Are less likely to be washed away by profuse sweating

This is why an aluminum sesquichlorohydrate antiperspirant is more effective in reducing sweating than the traditional ACH antiperspirant, particularly in humid conditions, physical activity or prolonged use.

Benefits for Brands and Formulators

Supreme sweat reduction, without the sting: ASCH provides clinical performance (at levels up to 25%) but with less skin irritation than you would experience with equivalent efficacy of aluminum chloride. So it’s a “best of both worlds” ingredient: good enough for clinical claims, but not so harsh for everyday applications.

Premium product positioning: Companies like Carpe use 15% aluminium sesquichlorohydrate in their classic products because it enables them to deliver the performance of a prescription product without prescription. In products for the premium or dermocosmetic market ASCH allows for premium pricing and supports claims of efficacy.

Sensitive skin compatibility: With a lower pH than aluminum chloride, ASCH is compatible with aftershave and for people with sensitive skin. An aluminum sesquichlorohydrate deodorant may be more likely to be prescribed by a dermatologist than an aluminum chloride.

Performance under pressure: Humidity, tropical climates, sports and travel retail, ASCH performs better than ACH.

Formulation Considerations

ASCH isn’t quite as plug-and-play as ACH. There are a few things formulators need to account for:

• Higher raw material cost: The more complex synthesis process and fewer global suppliers mean ASCH costs more per kilo than ACH. This is usually offset by the premium retail pricing it supports
• Tighter pH control required: ASCH needs a more precisely balanced pH environment to maintain efficacy and shelf stability. Solvent and buffer selection matters more here
• Limited supply chain: Pharmaceutical-grade ASCH comes from a smaller pool of certified manufacturers, which can mean longer lead times and higher minimum order quantities

The Third Option: Aluminum Chlorohydrate vs Aluminum Zirconium Tetrachlorohydrex

The current blog missed this comparison entirely, and it matters because aluminum zirconium tetrachlorohydrex gly (often shortened to “AZG” or just “aluminum zirconium”) is actually the most potent OTC antiperspirant active available.

A study published in Dermatologic Clinics found that antiperspirants using aluminum zirconium tetrachlorohydrex were roughly 34% more effective than those using aluminum chloride as the active ingredient. Most clinical-strength products from major brands like Dove, Secret, and Old Spice use AZG at 20% concentration for their strongest formulations.

Here’s how all three stack up:

Is Aluminum Sesquichlorohydrate Safe?

This is a top search term for this ingredient and it’s understandable. The debate over the use of aluminum in deodorants has been going on for decades, with claims that antiperspirants containing aluminum may cause breast cancer and Alzheimer’s disease.

Here’s the evidence:

Breast cancer: The fear was that the aluminum in antiperspirants could enter the breast through your skin, and promote the development of tumours. This has been the subject of several studies. According to the most recent scientific consensus, supported by the US Cancer Society and the US Food and Drug Administration (FDA), there is no evidence of a causal link between antiperspirants with aluminum and breast cancer. There is some in-vitro (cell culture) evidence that aluminum has an effect on estrogen receptors, but this has not been supported by cancer risk in people.

Alzheimer’s disease: This issue stemmed from early research showing high concentrations of aluminum in the brains of Alzheimer’s patients. But this has not been proven. According to the Alzheimer’s Association, the majority of experts no longer believe aluminum is an important risk factor.

FDA position: Aluminum sesquichlorohydrate is allowed by the FDA in antiperspirants at levels up to 25%, and it is considered safe for OTC products. The Cosmetic Ingredient Review (CIR) Expert Panel has also evaluated the safety of the aluminum chlorohydrate complexes such as ASCH and considered them safe for cosmetic use.

Who should be cautious: Aluminum-based antiperspirants should be avoided by anyone with kidney disease as their ability to excrete aluminum is reduced. This may result in neurotoxicity and other symptoms. This is a medical issue and not a consumer issue, but should be mentioned on product labels.

Skin irritation: It can cause some irritation, particularly on newly shaved skin. ASCH is better tolerated than aluminum chloride. Consumers with sensitive skin should always do a patch test.

So is aluminum sesquichlorohydrate safe? Yes, for most. Regulartory clearances, clinical trials and commercial use all point to that. The exceptions for kidney disease and sensitive skin are real but narrow, and should be dealt with via appropriate labeling as opposed to general safety concerns.

Aluminum-Free Deodorants: A Challenge for Formulators

It’s not possible to discuss aluminum chlorohydrate or aluminium sesquichlorohydrate in 2026 without mentioning the elephant in the room – the rise of aluminum-free deodorants.

The aluminum-free deodorant market will expand from USD 3.4 billion in 2025 to USD 6.2 billion by 2035 as part of the clean beauty movement and concerns about the safety of aluminum. Major brands are responding. In May 2025, Dove expanded its “0% Aluminum” line in North America and Europe with probiotic probiotics and plant-based moisturizers.

But here’s what’s missing in the marketing: aluminum-free deodorants aren’t antiperspirants. They will kill odour, but not sweat. That’s a fundamental functional difference. So there’s no effective over-the-counter (OTC) alternative for consumers who are looking for sweat control.

The upshot for formulators and brands is that there’s a place for both. The market is bifurcating:

• Aluminum products for consumers who want to reduce actual perspiration and need to exercise, live in a warm environment, have hyperhidrosis, or work in a professional environment
• Aluminum-free products for consumers who value clean ingredients and some degree of perspiration

Companies that can provide two brands, with distinct information on what they can and can’t do, are in a better position than those that choose sides.

Regulatory Landscape in 2026

Regulation of antiperspirant ingredients is getting serious, and formulators should take notice.

MoCRA (US): The Modernization of Cosmetics Regulation Act (MoCRA) now requires a cosmetic facility to be registered, products listed and adverse events reported. While the FDA classifies antiperspirants as OTC drugs (not cosmetics), deodorant-antiperspirant combination products are considered a special case. The new fragrance allergen labeling regulation, which will likely be proposed in May 2026, will affect the fragrance labeling on deodorants.

EU: The European Commission has been considering aluminum concentrations in cosmetics. While no new concentrations have been proposed (yet) as of April 2026, the European Scientific Committee on Consumer Safety (SCCS) has raised concerns about the total aluminum exposure from cosmetics as a result of repeated exposure to multiple sources. This is something formulators should keep an eye on if they have products in the EU.

Conclusion

So it comes down to what you want your product to do and for whom. ACH is the safe choice for commercial mass market product formulation, cost effective, multifunctional, and readily accepted around the world. ASCH is the next step up for brands looking for clinical effectiveness without the sting of aluminum chloride. AZG is the best for sweat blocking.

Consumer expectations are evolving fast. Aluminum-free is on the rise, but is not a substitute for the technical function of antiperspirant protection. Companies that understand the science, deliver the right grade, and don’t mislead about ingredient functions will win the confidence of consumers.

Elchemy works with brands to source antiperspirant and personal care ingredients such as pharmaceutical-grade and cosmetic-grade aluminum chlorohydrate, aluminium sesquichlorohydrate and aluminum zirconium tetrachlorohydrex gly, with complete COA, regulatory advice and affordable pricing from always verified global sources.