Quotations for Acetyl Tetrapeptide-3 arrive looking comparable and usually are not. The same INCI name covers neat peptide, pre-diluted solutions, and proprietary branded blends in which the peptide is one component among several. Until you know which of the three each offer describes, the price column is not measuring anything. This page covers what to establish first, what each test on a certificate proves, and which questions stay yours to answer after the material arrives.
Three different materials, one INCI name
Acetyl Tetrapeptide-3 is an acetylated four-amino-acid peptide, sequence Ac-Lys-Gly-His-Lys-NH2 (Ac-KGHK), CAS 827306-88-7, molecular weight approximately 487.6. That is the substance. What gets sold is one of:
- Neat peptide, supplied as a lyophilised powder and quoted per unit weight of peptide.
- A dilution or solution at a stated concentration, where the price per kilogram covers mostly carrier.
- A proprietary branded blend. The best known is Capixyl™, a branded ingredient from Lucas Meyer Cosmetics (IFF) that combines Acetyl Tetrapeptide-3 with red clover (Trifolium pratense) extract. Capixyl™ is that company's trademarked material; we do not supply it and make no claim to represent it. If a project specifically requires that branded blend, it has to be sourced from its owner or an authorised distributor.
The composition ratios inside any branded blend are its owner's proprietary information. Treat any supplier who volunteers them, or who offers to match them, with caution.
Purity is not content, and neither is concentration
In a neat peptide, HPLC purity reported by area normalisation tells you what share of the detected material is the target peak. In a commercial diluted or blended material it tells you considerably less, because the number may refer to the peptide input rather than the delivered product. A material can be built from 98% pure peptide and still contain very little peptide.
The figure that answers "how much peptide am I buying" is the active peptide content in the material as supplied. Ask for it explicitly, and ask what it was determined against. Content determination needs a suitable reference standard and a validated method; where a batch report carries purity but no content result, the label figure has not been demonstrated, and that is worth knowing before it is dosed against.
What each test proves
- Mass spectrometry (LC-MS) — identity. It confirms the molecule matches the declared sequence and mass. It says nothing about how much is present.
- HPLC — purity of the detected material, by area normalisation. Useful for comparing neat peptide lots; weak evidence about a blended commercial product.
- Assay / content — how much declared substance is actually in the material. This is the number that makes quotations comparable.
- Appearance, solubility, water content — handling properties that decide whether the material behaves in your process.
Our full reading order for these documents is in the COA, HPLC and LC-MS review guide, and how we confirm identity on our own batches is described here.
What to settle before a sample is worth running
A sample only earns bench time once the paperwork answers these:
- Which of the three material forms is being offered, and on what basis it is priced.
- The active peptide content in the supplied material, and the method behind that figure.
- Whether the COA is batch-specific and matches the batch you received.
- Solubility in the solvent system you intend to use, plus storage and handling conditions.
- Packaging and pack sizes, since these decide how much you must commit to in order to run a real pilot.
Sequencing this properly — documents, then sample, then pilot, then bulk — keeps the brief stable, and we set out that progression in this note on moving from lab sample to first bulk discussion.
What remains yours
Formulation compatibility, safety assessment, finished-product stability, and the regulatory position and permitted claims in each destination market are decided by you and your advisers, on your own testing. Supplier technical data informs that work; it does not replace it. Positioning for this ingredient stays cosmetic and appearance-focused, and the wording has to clear your target-market claims review before it reaches artwork.
What we can support
We supply Acetyl Tetrapeptide-3 for scalp-care and hair-care formulation projects, with COA and SDS/MSDS documentation, a specification sheet with purity information, samples for formulation evaluation, and bulk quotation against a stated quantity and destination market. Current specification scope is on the Acetyl Tetrapeptide-3 material page. If you are still choosing between this and Diaminopyrimidine Oxide for the same brief, the direction comparison is the better starting point.
Frequently Asked Questions
Is Capixyl the same as Acetyl Tetrapeptide-3?
No. Capixyl™ is a branded blend from Lucas Meyer Cosmetics (IFF) that contains Acetyl Tetrapeptide-3 together with red clover extract. Acetyl Tetrapeptide-3 on its own is the single INCI ingredient, CAS 827306-88-7.
Why do two Acetyl Tetrapeptide-3 quotations differ so much?
Usually because they describe different materials. Neat peptide, a stated-percentage dilution, and a branded blend carry very different amounts of peptide per kilogram. Establish the material form and the active content basis before comparing prices.
Does a high HPLC purity figure tell me the peptide content?
Not in a diluted or blended material. Purity describes the detected material; content describes how much declared substance is in what you receive. Ask for both, and for the method behind the content figure.