Buy MOTS-c Peptide: A Sequence, a Salt, a Spectrum

When you buy MOTS-c peptide you are ordering a specific molecule: the 16-residue sequence MRWQEMGYIFYPRKLR, supplied as a lyophilised powder, with a theoretical mass of approximately 2,174 Da. Everything on the listing above that is a claim. The mass is the part that can be measured.

That distinction organises this page. Identity, purity, water and endotoxin are things a laboratory can report on a lot. Grade, quality, pharmaceutical standard and research proven are things a listing can assert without any record behind them.

What you buy when you buy MOTS-c peptide at the molecular level

MOTS-c is unusual among research peptides in where it comes from. It is not a modified analogue of a hormone. It is a short open reading frame encoded within the mitochondrial 12S ribosomal RNA gene, described by Lee and colleagues in 2015, and the sequence sold commercially is the same 16 residues.

Read the sequence as a chemist would. MRWQEMGYIFYPRKLR contains two methionines, which are the residues most prone to oxidation in storage; a tryptophan and two tyrosines, which is why the powder absorbs at 280 nm; three arginines and a lysine, which is why the molecule is strongly basic and carries counterions; and a single glutamate. That composition is not trivia. It predicts the degradation route, the salt load and the chromatographic behaviour that a certificate reports.

Identity confirmation works from the fixed theoretical mass. Electrospray ionisation adds protons, so a spectrum shows a charge series rather than a single peak: the doubly protonated ion near m/z 1,088 and the triply protonated near m/z 726 for a mass around 2,174 Da. A certificate that reports an observed mass within instrument tolerance of the theoretical value has established the molecular formula. It has not established residue order, because a scrambled sequence weighs the same, which is why purity and identity are separate lines rather than one.

What the label states and what the certificate has to prove

The label on a research vial does a small job: product name, strength, lot number, storage condition, and a statement restricting the material to laboratory use. The lot number is the only part that connects it to anything. Without it the vial is anonymous and no certificate can be matched to it.

The last row is the one that most often has no entry. Reverse-phase purification uses trifluoroacetic acid, the peptide comes off as a TFA salt, and with four basic sites this sequence can carry several counterions at roughly 114 Da each. Residual trifluoroacetate is not inert either: it has been reported to inhibit proliferation of osteoblasts and chondrocytes, which makes it a variable in a cell assay rather than an accounting detail. Acetate-exchanged material exists and costs more.

Why a matching mass is necessary and not sufficient

A mass measurement answers one question well: does the sample have the elemental composition of the intended peptide. It answers a second question badly and a third not at all, and a certificate that reports only purity and mass leaves both open.

The second question is order. Any rearrangement of the same 16 residues has an identical formula and an identical mass, so intact-mass analysis cannot separate MRWQEMGYIFYPRKLR from a scrambled version of itself. Tandem mass spectrometry can, because fragmenting the molecule produces a ladder of ions whose spacings read out the residues one at a time. Very few research-supply certificates include it, and its absence is worth noting rather than treating as a defect: the combination of a single sharp chromatographic peak and a correct intact mass makes a gross sequence error unlikely, just not excluded.

The third question is what happened after release. Both methionines in this sequence oxidise, and each oxidation adds 16 Da, which is a shift an intact-mass measurement would resolve easily if anyone repeated it. Nobody does. The certificate describes the lot at the moment it was tested, not the vial in your hand after transit, so storage temperature and time between release and delivery remain unmeasured variables. Our guide to peptide stability and half-life covers why those variables are larger for some sequences than others.

MOTS-c where to buy UK, and what an import actually involves

The honest position for a British or European reader is that no authorised supply exists. MOTS-c holds no marketing authorisation from the MHRA or the EMA, which means no pharmacy, clinic or wholesaler can lawfully supply it as a medicine, and no amount of searching will surface a legitimate British medical route to it.

What searches do surface is storefronts presenting as British or European. Some hold stock. Many are reshippers, forwarding parcels from a wholesaler elsewhere, and a reshipping step is precisely where batch traceability breaks: bulk material bought in, relabelled with an internal reference, and forwarded with no lot number that matches any published certificate.

Ordering from a United States supplier makes the transaction an import. That has consequences that are ordinary and worth stating plainly rather than glossing. The parcel is subject to customs assessment on arrival. Import VAT and a courier handling fee are normally charged to the recipient before delivery. Importing an unlicensed medicinal product is a restricted activity under MHRA guidance, and a parcel can be held or refused. That risk sits with the buyer, and this site will not describe anything that bears on how a shipment is presented to customs.

The practical consequence is a longer and less predictable delivery window, and no domestic route for returns. Whether that changes the decision is a judgement, but it should be made with the position stated rather than assumed. The equivalent analysis for the other cluster on this site is in our United Kingdom purchase guide.

The checks worth running before the order is placed

All of them are documentary, and all of them are cheaper to run before payment than after. Ask for the certificate covering the lot that will ship to you, not a certificate for the product line. Confirm the issuing laboratory is named and can be found. Confirm there is a report date, and that it is a date rather than a year.

Then read the document itself rather than the summary. A chromatogram should be visible, with a wavelength and a retention time, and a mass spectrum should show a charge series rather than a single annotated number typed into a template. A certificate that consists only of a table of percentages is a claim about measurements, not a record of them.

Finally, check that the listing makes no human-use claim. A supplier that describes dosing, protocols or results in people is selling an unapproved drug regardless of what the label says, and that is a signal about the operation rather than about the peptide. The full criteria are in our sibling article on choosing a supplier, and the general framing in what research peptides are.

The evidence tier for the molecule in the vial

Buying the right molecule and buying a molecule worth having are separate questions, and this site grades the second one explicitly. The MOTS-c literature is largely cell culture and rodent work. Lee and colleagues characterised it in Cell Metabolism in 2015 as a regulator of metabolic homeostasis acting through AMPK, and a 2018 paper from the same group reported nuclear translocation under metabolic stress. Both grade as preclinical.

Human data on MOTS-c itself does not exist. The nearest record belongs to CB4211, an analogue developed by CohBar, which completed a Phase 1a/1b safety and pharmacokinetics study in 88 participants (NCT03998514) in April 2021 before the company wound down. An analogue is a different compound with different properties, so that study is context rather than evidence for the peptide you would be buying. There is no Phase 3 programme and no large human efficacy trial.

So the position is: a well-characterised sample of a molecule whose human effects are unestablished. Material sold for laboratory research is not manufactured, tested or released to the standards that apply to an approved medicine, and nothing on this page describes or implies human use.