Tranexamic acid and arbutin are two of the most counterfeited materials in the brightening category. Both are useful, both are well understood in the literature, and both are regularly supplied at a fraction of the stated content - or as something else entirely. The formulation chemistry is not the difficult part. The difficult part is buying them.
This article covers what each material is, which forms belong in a serum, what the specification has to state, and where the claim boundary sits. The last point matters more than usual in this category, because brightening is the area where cosmetic language and drug language are closest together.
Both actives need a specification, not a vendor claim
The recurring failure in brightening products is not a formula that does not work. It is a formula that contains the wrong material, or the right material at a level far below what was ordered, and nobody checked because the trade name sounded correct.
Both tranexamic acid and arbutin are cheap enough that substitution is profitable and expensive enough that buyers do not expect it. Both have purity questions attached. And both sit in a category where the finished product is usually white or pale, so an off-colour or an off-spec batch is not obvious on the bench.
The answer is unglamorous and effective: specify the INCI name, the assay, the assay method, and the impurity profile, and have the incoming material verified against it. That is the whole difference between a product that delivers and a product that carries a claim.
Tranexamic acid: what belongs in a serum
Tranexamic acid is a small, water-soluble molecule with a well-characterised profile. It dissolves easily, it is stable in a normal cosmetic pH range, and it does not need an anhydrous base or barrier packaging.
That makes it an unusually easy active to formulate with. The constraints are commercial and regulatory rather than chemical:
- It is water-soluble and ionic. It contributes to the electrolyte load of the formula, which matters if the base relies on a viscosifying polymer - the same interaction described in our hyaluronic acid article.
- It is used at comparatively high levels. The levels used in the published work are measured in whole percentage points rather than fractions, which is unusual for an active and makes the assay question more significant rather than less.
- Its status varies by market. In some markets it is treated as an ordinary cosmetic ingredient. In others, products making a brightening claim fall into a more regulated category with its own registration route. That is a market-entry issue, not a bench issue, and it has to be settled before the formula is locked.
Tranexamic acid: stability, pH and the salt form
The material is stable across the pH range a serum occupies, and it is not strongly light-sensitive. The practical stability question is not degradation of the active but interaction with everything else - in particular whether the pH chosen for a co-ingredient such as vitamin C is compatible.
The salt forms are worth understanding. Tranexamic acid is supplied as the free acid and as salts, and the different forms have different solubilities and different pH behaviour when dissolved. The INCI name on the specification is what tells you which one you have. Treating them as interchangeable is the same error as treating sodium hyaluronate and hyaluronic acid as one material.
Arbutin: alpha, beta and the one to be careful with
Arbutin is a glycoside - a sugar joined to a functional group - and the family has three members that appear in commerce.
Beta-arbutin is the material that occurs naturally and the one most often used historically. Alpha-arbutin is the synthetic anomer, and it is the form most modern brightening products are built on because it is more stable and is used at lower levels for a comparable claim. The two are different molecules, they behave differently, and they are not interchangeable in a formula or on a specification.
Deoxyarbutin is the third. It is far more potent than either, it is much less stable, and it has a documented tendency to convert to a material that attracts regulatory attention. It is restricted or effectively unavailable in several markets, and where it is available it demands stability data that most brands are not prepared to pay for.
The practical position: alpha-arbutin is the mainstream choice, beta-arbutin is the traditional one, and deoxyarbutin is the one to avoid unless you have a specific reason and the data to support it. A supplier who offers "arbutin" without specifying which one has not answered the question.
The hydroquinone question and how to test for it
Arbutin works by releasing a hydroquinone-related moiety, and hydroquinone itself is a restricted or prohibited ingredient in cosmetics in most markets.
That means two things for a buyer.
First, the raw material has to be tested for free hydroquinone content, and the limit has to be stated on the specification. This is a standard test and there is no reason for a competent supplier to be unable to provide it.
Second, the finished product can acquire free hydroquinone over time if the arbutin degrades. That is a stability question, not just an incoming-goods question, and it is the reason a brightening formula with arbutin needs an assay at the end of the stability period rather than at release only.
This is the single most important testing point in the whole category. A product that develops free hydroquinone in the bottle has a compliance problem that no amount of label wording can solve. Our INCI and ingredient safety article covers how the restriction is expressed across markets.
Purity, assay and why the specification is the product
For both materials, four items belong on the specification and in the technical file:
- INCI name - including the specific form, not the family name.
- Assay - the content of the actual material, with the method named.
- Impurity profile - for arbutin, free hydroquinone in particular.
- Identity confirmation - the test that proves the material is what the certificate says it is.
None of this is unusual. It is what an ingredient specification looks like in any disciplined supply chain. The reason it needs stating here is that this category has a well-documented history of certificates that describe a material the drum does not contain, and the only defence is independent verification of incoming goods.
The two actives compared
| Property | Tranexamic acid | Alpha-arbutin | Beta-arbutin |
|---|---|---|---|
| Solubility | Freely water-soluble | Water-soluble | Less soluble than alpha |
| Typical use level | Whole percentage points | Low, fractional to low single digit | Higher than alpha for the same positioning |
| Stability | Good across normal serum pH | Good; keeps its advantage over beta | Less stable |
| Main testing risk | Assay and market status | Free hydroquinone, at release and in stability | Free hydroquinone; form confusion with alpha |
| Formulation difficulty | Low | Low to moderate | Moderate |
Combining with niacinamide and vitamin C
Brightening products are usually built from more than one active, and the pairings are well travelled.
Niacinamide combines cleanly with both. It is neutral, water-soluble and stable, and the combination is the most common brightening pairing in commercial serums - see our niacinamide article for what the concentration actually buys.
Vitamin C is more complicated, because L-ascorbic acid needs a strongly acidic pH and arbutin is happiest nearer neutral. The pairing works if the pH is chosen for the whole formula rather than for the vitamin C alone, and the more stable vitamin C forms make that easier - see our vitamin C comparison article.
What does not work is putting four brightening actives in one product at levels chosen independently. The load of electrolytes, the pH compromise and the cost all add up, and the result is usually a product that is weaker on every count than a well-built single-active formula.
Preservatives and the acidic environment
Many brightening formulas sit at a mildly acidic pH because of a co-ingredient. That environment changes how effective some preservative systems are, and it also affects the ionisation state of both actives.
The answer is preservative efficacy testing on the finished formula at its actual pH rather than on a generic base - see our preservative article. For a formula containing arbutin, add the free hydroquinone assay to the same stability run and read both results together.
The claim boundary: brightening, whitening and where the line sits
This is the part of the category that causes the most trouble, and the trouble is not about honesty. It is about which set of rules a product falls under.
Three tiers exist in most markets:
- Appearance claims. Skin looks more even, the look of dark marks appears reduced, the complexion looks brighter and more radiant. These are cosmetic appearance claims.
- Colour-change claims. Some markets treat an explicit whitening or lightening claim as a regulated function rather than an ordinary cosmetic one, with its own registration or notification route. What counts as a colour-change claim differs by market.
- Condition claims. Anything describing a pigmentary disorder, or any comparison to a treatment, is outside the cosmetic zone entirely.
The safe construction in any market is a description of appearance, tied to consumer testing on the specific claim. Our brightening formulation article covers how the claims are built and substantiated, and our efficacy testing article covers the general approach.
Market status and the brief
Because the claim tier decides the regulatory route, the target market has to be settled before the formula rather than after it.
Some markets accept an even-tone appearance claim on an ordinary cosmetic notification. Others require a registration process for products making a colour-change claim, with a longer timeline and a dossier. The same formula can be legitimate in one market and non-compliant in another purely because of the wording on the pack.
That is not a reason to avoid the category. It is a reason to decide the claim and the market at the start. Our market-entry guides cover the main routes - the US guide, the Japan and Korea guide and the labelling guide - and our documentation article covers what a registration route adds to the paperwork.
Testing to commission
- Assay on both actives at release and at the end of the stability period, with the method named.
- Free hydroquinone in the arbutin raw material and in the finished formula across stability.
- Identity confirmation on incoming material, independent of the supplier certificate.
- Stability on the finished pack, including a light-exposure arm for anything in translucent packaging.
- Preservative efficacy at the formula's actual pH.
- Consumer use testing against the appearance claim you intend to print, on a panel matched to the target customer.
How to write the brief
Name the specific forms: tranexamic acid as the free acid or a named salt; alpha-arbutin rather than "arbutin". State the assay you require and the impurity limits, especially free hydroquinone. State the market and the claim tier. Then state whether the formula needs to hold a vitamin C active, because that decision fixes the pH and the pH fixes a lot of the rest.
What to avoid: a brief that says "brightening serum with arbutin and tranexamic acid". It is a category description, not a specification, and it leaves every decision that determines whether the product works to someone else.
Where our brightening capability fits
We formulate tranexamic acid and alpha-arbutin systems with the specification and the assay testing built into the sourcing, and with the claim tier matched to the market before the formula is locked. Formats include a brightening facial essence capsule, a whitening dark spot corrector face cream and a brightening body wash where the claim sits in a rinse-off format.
We work with brands on private label (your brand on a proven base), OEM/ODM contract manufacturing, and full custom formula development - whichever matches where your brand is today.
Tell us the market, the claim tier and the forms you want, and we will come back with the specification and the testing plan rather than a name on an ingredient list. Start at our inquiry page, email capsulebiotech@163.com, or message the right team on WhatsApp: Capsule Series (capsules only) +86 158-7655-5319, Cosmetics Series (serum, hair care, body care, fragrance) +86 158-7655-5319.
General manufacturing information, not regulatory or legal advice. Ingredient status and claim limits vary by market.