Description
PrymaLab · Research Use Only
Glutathione 1500mg
The cell already has millimolar amounts of this
Every other article in this catalogue is absent from a cell until somebody adds it. Glutathione peptide is already there, at concentrations measured in millimoles rather than micromoles, which makes the question of what adding more does considerably harder than it looks.
Specification Table
| Property | Value |
|---|---|
| Compound | Glutathione, reduced form |
| Common abbreviation | GSH |
| Residue count | 3 |
| Molecular weight, calculated | Approximately 307.3 g/mol |
| CAS | 70-18-8 |
| Reported intracellular concentration | Millimolar in most cell types, commonly cited in the range of one to ten |
| Extracellular concentration | Orders of magnitude lower, typically micromolar |
| Principal extracellular enzyme | Gamma-glutamyl transpeptidase, which cleaves it at the cell surface |
| Consequence of that | Most exogenous material is broken down before it can enter a cell intact |
| Oxidised form | GSSG, a disulfide-linked dimer |
| Nominal fill | 1500 mg |
| Aromatic residues | None, so 280 nanometre detection is not usable |
| Regulatory status | No approved formulation in the United States for this presentation |
| Appearance | White crystalline powder |
| Storage | Sealed, dry, cool and protected from light and air |
Why Does the Existing Glutathione Peptide Pool Change the Question?
A compound absent from a system produces a clean experiment. Add it, measure what changes, and the comparison holds.
Glutathione peptide is not absent from any system that contains living cells, and the amount already present is large.
Published figures put the intracellular concentration in the millimolar range across most cell types, which is a thousandfold above where most compounds in this catalogue are studied.
Adding exogenous material to that is not introducing a compound. It is perturbing a pool that is already substantial and already regulated.
Regulation is the part that makes it hard. Cells synthesise it continuously, consume it in ordinary metabolism, recycle the oxidised form back, and export it.
Every one of those processes responds to the concentration, so a system given more will adjust rather than simply hold the higher figure.
What that means practically is that a concentration-response relationship for this compound is not a straightforward function of what was added.
It depends on what the pool was before, on how fast the cell can adjust, and on which of the several handling processes the measurement is actually sensitive to.
None of that makes the compound uninteresting as a research article. It makes the experimental design carry more of the weight than the material does.
A study that measures the intracellular pool at the start and again at the end, rather than only the amount added, is asking a question the system can answer.
Does Exogenous Material Even Get In?
Whether exogenous glutathione peptide gets into a cell at all is the second problem, and it is more concrete than the first.
Intact glutathione crosses cell membranes poorly. It is a charged tripeptide, and most cell types have no dedicated uptake transporter for it.
What happens instead is a well-characterised cycle that begins outside the cell.
Gamma-glutamyl transpeptidase sits on the outer face of the membrane and cleaves the gamma-glutamyl bond, releasing the remaining dipeptide.
That dipeptide is cleaved again by a second surface enzyme, and the resulting free amino acids are taken up by ordinary amino acid transporters.
Inside, the cell rebuilds glutathione from those components using two enzymes and consuming energy.
So the material that arrives is largely not the material that was added. It is the constituent amino acids, reassembled.
That has a specific interpretive consequence and it is the one most often skipped. An effect observed after adding this compound may reflect delivery of cysteine rather than delivery of glutathione.
Cysteine availability is the rate-limiting step in glutathione synthesis in most cells, so supplying it produces effects that look like supplying the tripeptide.
Distinguishing the two needs a control, and the obvious one is adding equimolar free cysteine alongside the other components and comparing.
A study that runs that arm can say something about glutathione specifically. One that does not has measured something about cysteine supply.
What Does 1500mg Change?
The fill size here is unlike anything else in this range. It reflects what the compound is rather than an unusual packaging choice.
Most peptides here come in single or double-digit milligrams, being expensive to make and used at low concentrations.
Glutathione peptide is manufactured at industrial scale, is inexpensive per gram, and is used at concentrations where milligram quantities would not last.
A gram and a half is therefore a working quantity rather than a bulk purchase, which inverts the usual economics of this catalogue.
Two practical things follow. The first is that weighing is straightforward. A balance error that would matter on a 2 mg fill is irrelevant at this scale.
The second is that solubility and osmolality become the constraints instead. Glutathione dissolves well in water and a concentrated solution is markedly acidic.
A solution made at high concentration without buffering will sit at a pH that most cell-based systems do not tolerate, and neutralising it adds salt that raises osmolality.
Both are manageable and neither is obvious to somebody whose habits were formed on milligram vials of expensive peptide.
Preparing a concentrated stock, neutralising it carefully, and checking the final osmolality is the sequence that avoids a result driven by pH rather than by the compound.
What Should the Certificate Show?
A glutathione peptide certificate carries five fields, and the first two follow from the thiol.
The ratio of reduced to oxidised material, or at minimum a figure for the reduced form. A purity percentage that does not distinguish them is close to meaningless.
A free thiol determination, which measures the reduced form directly rather than inferring it.
Identity by mass, where approximately 307 is the reduced monomer and approximately 613 is the oxidised dimer.
Purity by chromatography at 214 nanometres. This molecule carries no aromatic residue, so a 280 nanometre reading tells you nothing.
Lot number and manufacturing date, which matter more than usual because the reduced form converts to the oxidised one on storage.
A certificate quoting a single purity figure without saying which form it refers to has left the most important question open.
For an article this cheap, asking for the reduced-form figure specifically is a reasonable request rather than an imposition, and a supplier who cannot provide it is selling an unknown mixture.
What Does the Oxidised Form Change?
Glutathione peptide exists in two forms and a preparation is always some mixture of them, which is unlike almost anything else in this catalogue.
The reduced form carries a free thiol on its cysteine. Two of those can join through that thiol to give a disulfide-linked dimer.
That dimer is the oxidised form, and it is not a degradation product in the ordinary sense because cells interconvert the two constantly as part of normal metabolism.
What that means for a vial is that the ratio between them is a property of the material rather than a defect in it.
The ratio is also the thing most experiments are actually sensitive to. Cellular redox state is commonly expressed as that ratio rather than as either concentration alone.
So adding material of unknown ratio to a system whose ratio is the readout is a design problem rather than a purity problem.
A certificate quoting a single purity figure without saying which form it refers to leaves that open, and a figure for the reduced form specifically is what resolves it.
The two forms are easy to distinguish analytically. The dimer is twice the mass of the monomer, which no instrument can miss.
A free thiol assay measures the reduced form directly and takes minutes, which makes it a reasonable check to run on receipt rather than to rely on the supplier for.
Doing that once on a new lot establishes a baseline, and repeating it before a run that matters establishes whether the material has drifted since.
How Should It Be Stored?
Storage here is about keeping air away rather than keeping it cold, which reverses the usual advice.
The reduced form converts to the oxidised dimer on exposure to air, and the reaction proceeds in the solid state slowly and in solution quickly.
A sealed container is therefore doing more work than the temperature is, and a partly used container that has been opened repeatedly is the realistic failure case.
Dry, cool, sealed and dark is the specification, and the seal is the part that matters most.
Solutions should be prepared fresh. A stock held for a week has converted a measurable fraction and nothing about its appearance reveals how much.
Where a stock has to be kept, the addition of a chelating agent slows the metal-catalysed part of the reaction, and low pH slows it further.
That second point conflicts with the need to neutralise for cell work, which is a real tension rather than an oversight, and it is why fresh preparation is the better answer.
Aliquoting the solid rather than the solution is the practical route at this fill size, since a gram and a half divided once is easier to manage than a solution divided repeatedly.
Record lot, the reduced-form figure from the certificate, the date the solid was first opened, and the date and pH of any solution prepared from it.
The date of first opening matters most, and nobody writes it down.
A final point about buying at this scale rather than at peptide scale.
A gram and a half will outlast most studies, which means the material sits in storage rather than moving through it.
For a compound whose reduced form converts on standing, a purchase that lasts two years is a purchase that degrades for two years.
One further point about record keeping for a compound that changes on standing.
The useful field is not the purchase date but the date the container was first opened, since that is when air reaches the powder.
A vial opened four times over a year has a different history from one opened once, and no certificate can describe that history because it happened after shipping.
Recording open events alongside the glutathione peptide lot number is the only way that history survives.
Published Literature
Selected references on the metabolism of this compound and on the surface enzyme that governs its uptake.
- Meister A, Anderson ME. Annual Review of Biochemistry. 1983;52:711-760. DOI: 10.1146/annurev.bi.52.070183.003431
- Lu SC. Biochimica et Biophysica Acta. 2013;1830(5):3143-3153. DOI: 10.1016/j.bbagen.2012.09.008
- Hanigan MH. Advances in Cancer Research. 2014;122:103-141. DOI: 10.1016/B978-0-12-420117-0.00003-7
- Bachhawat AK, Yadav S. IUBMB Life. 2018;70(7):585-592. DOI: 10.1002/iub.1756
Frequently Asked Questions
What is glutathione peptide?
A tripeptide of glutamate, cysteine and glycine, calculated at approximately 307.3 daltons in the reduced form and carrying CAS 70-18-8.
Why is it different from everything else here?
Because cells already contain it, at concentrations in the millimolar range across most cell types. Every other article in this catalogue is absent until somebody adds it.
Why does that make the experiment harder?
Adding material perturbs a pool that is already substantial and already regulated. Cells synthesise it, consume it, recycle the oxidised form and export it, and all of those respond to concentration.
Does exogenous material enter cells intact?
Largely not. It is a charged tripeptide and most cell types have no dedicated transporter for it.
What happens to it instead?
Gamma-glutamyl transpeptidase on the outer membrane face cleaves it, a second surface enzyme cleaves the remaining dipeptide, and the free amino acids are taken up by ordinary transporters.
So what actually gets in?
The constituent amino acids, which the cell then uses to rebuild the tripeptide internally. The material arriving is not the material that was added.
What does that mean for interpreting a result?
An observed effect may reflect delivery of cysteine rather than of glutathione, because cysteine availability is the rate-limiting step in synthesis for most cells.
What control settles that?
Adding equimolar free cysteine alongside the other components and comparing. A study running that arm can say something about the tripeptide specifically.
Why is the fill 1500mg?
Because the compound is manufactured at industrial scale, is inexpensive per gram, and is used at concentrations where milligram quantities would not last. A gram and a half is a working quantity here.
What becomes the constraint at that scale?
Solubility and osmolality rather than weighing accuracy. A concentrated solution is markedly acidic, and neutralising it adds salt that raises osmolality.
What should the certificate distinguish?
Reduced from oxidised material. A purity percentage that does not say which form it refers to is close to meaningless, and roughly 307 is the monomer against roughly 613 for the dimer.
What matters most in storage?
Keeping air out rather than keeping it cold. The reduced form converts to the oxidised dimer on exposure, slowly as a solid and quickly in solution.
Compliance Statement
Glutathione peptide is sold exclusively for laboratory research use. It is not a drug, food, or cosmetic product, and it is not a dietary product of any kind. It is not approved by the FDA or any comparable authority for human or veterinary use, it is present endogenously at millimolar intracellular concentration so an experiment adding it is perturbing an existing regulated pool rather than introducing a compound, most exogenous material is cleaved at the cell surface before entry so an observed effect may reflect amino acid supply rather than the intact tripeptide, and no compound in this range is offered for any human or veterinary purpose. This product is not intended to diagnose, treat, cure, or prevent any disease. It must not be given to humans or animals. Purchase is restricted to qualified researchers and institutions operating within applicable laws. All handling is the responsibility of the purchasing laboratory.
Other formats of Glutathione
Glutathione is also stocked as Glutathione 250mg Nasal Spray. Each listing states its own quantity and concentration, and the pen and vial comparison explains what changes between formats.
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