The science · 02 TXA5

The name carries one active. The vial carries two.

A technical record of this ampoule: what is in the vial, how each figure is stated, and what has not been measured.

Specifications · formulations · provenance

Units and conventions

Concentration
Stated in ppm and as percent by weight. 10,000 ppm = 1%.
Length
Needle diameter in micrometers (µm). Depth in millimeters (mm). 1 mm = 1,000 µm.
What a concentration is
The amount present in the sealed vial. It is not a statement about how much crosses the barrier.
Mass figures
Where a mass in grams is given it assumes a density of about 1 g/mL. The manufacturer has not published a density, so every mass here is an estimate from volume.

What is in the vial

Tranexamic acid
50,000 ppm = 5.0005% by weight, the maximum that stays dissolved
Niacinamide
20,000 ppm = 2% by weight
L-ascorbic acid
100 ppm = 0.01% by weight
Glutathione
0.5 ppm = 0.00005% by weight
Fragrance
None added
Format
50 mL crimp-sealed medical glass, aluminum crimp, rubber septum, flip-off cap. Filled under low oxygen
Origin
Developed and made in South Korea

Two actives, one name

This ampoule is named for tranexamic acid. Niacinamide is present at 2% and is not in the name.

02 TXA5 BRIGHTENING ACTIVE MASS IN THE SEALED VIAL 50 0 50 mL CRIMP-SEALED GLASS ≈50 g of liquid at an assumed ≈1 g/mL Tranexamic acid 50,000 ppm · 5% ≈2.5 g 157.2 g/mol TXA5 is this one: tranexamic acid at 5% Niacinamide 20,000 ppm · 2% ≈1.0 g 122.1 g/mol the name does not mention this one 0 0.5 1.0 1.5 2.0 2.5 3.0 GRAMS IN THE SEALED VIAL, LINEAR SCALEALSO PRESENT Ascorbic acid not published Glutathione not published No bar is drawn for these two, because neither concentration is published. Unpublished is not the same as small, and this plate does not say which.THE ARITHMETIC mass in the sealed vial, not what reaches skin 50 mL × ≈1 g/mL, assumed and not measured ≈50 g tranexamic acid, 50,000 ppm = 5% by weight of ≈50 g ≈2.5 g niacinamide, 20,000 ppm = 2% by weight of ≈50 g ≈1.0 g
The name labels one active. The vial holds two at published concentrations, and two more it puts no number on at all. TXA5 decodes as tranexamic acid at 5%, which is 50,000 ppm, and that is the whole of what the name carries. Niacinamide sits in the same sealed vial at 2%, 20,000 ppm, and appears nowhere in the name. Bar length is mass on a linear gram axis from a common zero, with nothing exaggerated to fit: about 2.5 g against about 1.0 g, a bar 2.5 times as long because the mass is 2.5 times the mass. Both gram figures rest on one assumption, which is stated on the plate rather than buried. Density is taken as about 1 g/mL for an aqueous ampoule, so 50 mL is treated as about 50 g. That is an assumption and not a measurement, and every gram figure here moves with it. Ascorbic acid and glutathione are in the formula and are drawn with no bar, because no concentration is published for either one. Unpublished is not the same as small, and this figure does not say which it is. Molecular weights are the published values, 157.2 g/mol and 122.1 g/mol, given for reference alongside the mass. Everything on this plate is composition and only composition: what is sealed inside the vial, not how much of it reaches skin, and not what any of it does. The vial is drawn as a schematic. Only the two bars are to scale.

Molecule size against the barrier

Every active in the range plotted against a rough size gate from the permeation literature.

UNDER 500 DALTONS OVER 500 DALTONS 1000 750 500 250 0 MOLECULAR WEIGHT (DALTONS) 122.1 157.2 267.2 402.9 802.1 889.0 500 DALTONS PASSIVE PERMEATION RULE OF THUMB Niacinamide Tranexamic acid Adenosine Copper tripeptide-1 Palmitoyl pentapeptide-4 Acetyl hexapeptide-801 · 02 02 01 · 03 03 03 03 01 / 02 / 03 = the ampoule each active appears in. Copper tripeptide-1 is plotted as the copper complex.
Reference figure, citation outstanding. The 500 dalton mark is a rule of thumb from the skin permeation literature, not a re:tones measurement and not a hard physical law. Treat it as a rough size gate rather than a verdict: under 500 Da does not mean a molecule gets through intact skin, and over 500 Da does not mean it never does. What the plot does show is that these six actives are not one population. Four sit under the heuristic and two sit several times above it, and that split is the argument for opening a channel rather than assuming the barrier will let everything through. Values are published molecular weights on a linear axis. Copper tripeptide-1 is plotted as the copper complex, 402.9 Da; the GHK peptide on its own is 340.4 Da.
01

Formulated for an open channel

An ampoule meant to meet skin that has just been opened is a different brief from a serum meant to sit on an intact barrier. It arrives sterile and single integrity, and it is dispensed at the moment of contact rather than applied afterwards.

You cannot open skin and then open a pump.

02

The manufacturer's dataset

The laboratory in South Korea that makes this ampoule keeps an engineering dossier on it. The owner of this shop asked for the whole thing to be published rather than a selected line or two. It is below, in full, at the numbers the laboratory states.

Read one thing first. Every figure here was taken in a named test system. A bench rig, a dish of cells, an enzyme in a tube, or a piece of skin kept alive outside a body. None of them was taken on you.

So each figure is printed with its method beside it, never underneath in small type. A laboratory number with no method attached reads like a forecast about your own face, and it is not one. With the method attached it goes back to being what it is, which is a true record of something somebody measured.

The method is not the fine print. The method is the claim.

The plain-language methods note is next, and every table on this page links back to it.

How to read these figures

Manufacturer-stated
The figure comes from the laboratory that makes this ampoule. It is published as given, with the test it came from. re:tones has not repeated it.
In vitro
In glassware. Cells, enzymes or tissue in a dish, outside a body. It shows what a molecule does to a target. It does not show what a product does to a face.
Ex vivo
On living tissue taken out of the body and kept alive for the test. A melanocyte study run ex vivo is run on real pigment cells in real tissue, under a UV lamp, on a bench. Closer to skin than a dish. Still not a person.
Enzymatic assay
An enzyme in a tube, the compound added, and a measurement of how much the enzyme slows down. The tyrosinase figure below comes from this kind of test.
Tyrosinase
The enzyme that starts the chain that makes melanin. Slowing it in a tube is not the same as changing a face.
Franz cell diffusion assay
A bench rig. Skin or a membrane is clamped between two chambers. The formula goes on top and the fluid underneath is sampled over time, to see how much crossed and how fast. It is the standard way to compare delivery. The skin in the rig is not attached to anybody.
Molar ratio
A ratio counted in molecules rather than in weight. 200:1 means two hundred molecules of one for every molecule of the other.
n
How many were tested. A figure with no n is a figure you cannot weigh.
ppm
Parts per million. 10,000 ppm is 1%.
MST, maximum solubility threshold
The most of something that stays dissolved. Go past it and it comes back out as crystals in the vial.
Test system not stated
The dossier gives the figure but does not say what it was measured in. Those rows are marked, because an unnamed method is worth less than a named one.
What none of this is
None of these figures was measured on somebody using this product at home. None of them is a statement about your skin, and none of them tells you what to expect.

Manufacturer laboratory data, 02 Brightening

From the 2026 engineering dossier held by the laboratory in South Korea that makes this ampoule. Manufacturer-stated throughout.

What was measuredResult as statedTest system, sample and date
Tranexamic acid concentration5.0005% by weight, the maximum solubility thresholdComposition sheet for the filled vial. A concentration, not a test result
What the threshold isAbove 5.0005% the acid stops dissolving and crystallizes in the vial in ordinary storageManufacturer-stated formulation limit, 2026 dossier
How the threshold is heldpH at 6.00 (±0.02), butylene glycol at 5.0005% as co-solvent, and compounding in the cold at 4.2°CProcess specification, 2026 dossier
UV-induced melanocyte activationSuppressed 68.4%Ex vivo studies. 2025
How tranexamic acid does thatAntagonism of the plasminogen and plasmin pathway, with suppression of PGE2Manufacturer-stated mechanism of action
Niacinamide concentration2% by weight, 20,000 ppmComposition sheet for the filled vial
How niacinamide does its partPARP-1 inhibition, and more ceramide synthesisManufacturer-stated mechanism of action

5.0005% is a solubility limit, not a statement about how much anybody needs. How to read these figures.

The 200:1 redox couple

L-ascorbic acid at 100 ppm and glutathione at 0.5 ppm, formulated at a 200:1 molar ratio. The pair is in the vial to keep each other working.

What was measuredResult as statedTest system, sample and date
L-ascorbic acid concentration100 ppm, 0.01% by weightComposition sheet, 2026 dossier
Glutathione concentration0.5 ppm, 0.00005% by weightComposition sheet, 2026 dossier
The ratio200:1 molar, described by the laboratory as the stoichiometric optimum for the cycleManufacturer-stated formulation choice
How the cycle runsL-ascorbic acid gives up an electron to neutralize a peroxyl radical and becomes dehydroascorbic acid. Glutathione hands an electron back and returns it to the active form. The cycle repeatsManufacturer-stated mechanism of action
Antioxidant activity sustained6.2 hours, 3.7 times longer than L-ascorbic acid on its own2026 dossier. Test system not stated
Intracellular glutathioneRaised 4.7 times2026 dossier. Test system not stated
Tyrosinase inhibition51.3%Enzymatic assays. 2026 dossier

Ascorbic acid browns in air, which is why this vial is filled under low oxygen and crimp-sealed rather than pumped. How to read these figures.

The delivery platform, measured on a bench

All three ampoules ride the same seven-stage nano-vector platform. It is the payload half of the system, engineered for a channel the device has already opened. Manufacturer-stated, 2026 dossier.

What was measuredResult as statedTest system
Payload reaching the dermal-epidermal junction94.7% (±2.1%)Franz cell diffusion assay, fluorescence-tagged actives. In vitro
Time to arrival4.7 minutes (±0.3 minutes)Same Franz cell assay. In vitro
Left on the surfaceUnder 5.3% retained in the stratum corneumSame Franz cell assay. In vitro
Mean particle diameter147.3 nm (±2.1 nm)Dynamic light scattering, 173° backscatter. In-process specification
Polydispersity indexUnder 0.08Dynamic light scattering. Batch acceptance criterion. A batch above 0.08 is rejected
Zeta potential-35.2 mV (±2.8 mV)Electrophoretic measurement. Batch acceptance criterion
Diffusion coefficient4.2 × 10⁻¹¹ m²/s, against 1.1 × 10⁻¹¹ m²/s for a conventional carrier2026 dossier. Test system not stated
Stages in the platformSeven, from water purification through to stability validationManufacturer process description
SealingHermetic, under low oxygen, to keep the ascorbic acid and the glutathione from oxidizingManufacturer process description
Stability24 months at room temperature, with no drift in particle size, pH or colorAccelerated aging, 6 months at 40°C and 75% relative humidity

A Franz cell is a bench rig, not a face, and 94.7% is what crossed a membrane in that rig. The device is what opens the channel this platform was engineered for. Neither half is sold as the whole system. How to read these figures.

Evidence grades

Substantiated
Traceable to a manufacturing specification, a supplier ingredient statement, or the physical product.
Manufacturer-stated
A measurement supplied by the laboratory that makes the ampoule, published with the test system it came from. re:tones has not repeated it and does not present it as a result on a customer.
Test system not stated
The dossier gives the figure without saying what it was measured in. Printed as given, and marked.
Reference figure
A published literature value used for scale, not a re:tones measurement.
Not published
The manufacturer has not supplied it. Listed rather than estimated.
Not claimed
re:tones has run no consumer panel and no clinical study of its own. Where a percentage appears on this site it belongs to a manufacturer measurement in a named test system. It is not a re:tones result and not a statement about any individual.

Claims ledger, this ampoule

Every figure this page uses and what it rests on.

Claim What it rests on Status
Tranexamic acid 50,000 ppm Manufacturer ingredient statement Substantiated
Niacinamide 20,000 ppm Manufacturer ingredient statement Substantiated
Mass in grams per vial Derived from volume assuming about 1 g/mL Estimate, density not published
L-ascorbic acid 100 ppm and glutathione 0.5 ppm Manufacturer composition sheet, 2026 dossier Substantiated
5.0005% as a solubility ceiling Manufacturer formulation limit, 2026 dossier Manufacturer-stated
UV-induced melanocyte activation suppressed 68.4% Manufacturer ex vivo studies, 2025 Manufacturer-stated
Tyrosinase inhibition 51.3% Manufacturer enzymatic assays Manufacturer-stated, measured on an enzyme in a tube
6.2 hours of antioxidant activity, 3.7 times L-ascorbic acid alone Manufacturer 2026 dossier Manufacturer-stated, test system not stated
Intracellular glutathione raised 4.7 times Manufacturer 2026 dossier Manufacturer-stated, test system not stated
94.7% to the dermal-epidermal junction in 4.7 minutes Manufacturer Franz cell diffusion assay, in vitro Manufacturer-stated, measured on a bench rig
Which ingredient is responsible for any effect Not established by re:tones Not claimed
Any effect on your tone or pigment re:tones has run no consumer panel and no clinical study Not claimed

Every figure on this page names its own basis.

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