Preloaded Autoinjector | Cardiogen | 3ml Pen | 20mg

The cardiogen pen is a preloaded 3ml research autoinjector holding the tetrapeptide L-alanyl-L-glutamyl-L-aspartyl-L-arginine (Ala-Glu-Asp-Arg, AEDR) in solution at 20/3 mg/ml, giving 20mg in the device. One bond in that sequence, Asp3 to Arg4, can rearrange to an isomer with exactly the same molecular weight, so the main ageing route leaves no trace on a purity-by-mass check.

Specification Table

What Changes When Cardiogen Ships in Solution?

Dissolving Ala-Glu-Asp-Arg puts a 489 Da tetrapeptide with three carboxylates and one guanidinium into water, where two hydrolytic routes and one rearrangement compete, and only the rearrangement is invisible to a mass measurement.

Begin with what cannot happen. There is no asparagine or glutamine, so no deamidation. No methionine, cysteine, tryptophan, histidine or tyrosine, so nothing to oxidise, no disulfide to scramble and no chromophore to absorb bench light. Nothing here fibrillates: a fully solvated tetrapeptide carrying four charges does not stack into sheets, so any particulate in this device is contamination, precipitated counter-ion or excipient, never aggregated peptide.

The route that matters is aspartate isomerisation at position 3. The backbone nitrogen of Arg4 attacks the side-chain carbonyl of Asp3 and closes a five-membered succinimide ring, losing a water molecule. That ring then reopens, and it reopens two ways: back to the original alpha-linked peptide, or to the beta-linked isoaspartyl form in which the backbone now runs through the aspartate side chain. Some of the material racemises to D-aspartate on the way. The isoaspartyl product weighs 489.49 g/mol, the same as the parent, because the ring closure lost a water and the ring opening put it back. An intact-mass check on an aged cartridge reports the parent mass and says nothing at all.

Two things soften that. Succinimide closure needs the backbone nitrogen to reach the side-chain carbonyl, and the bulky arginine side chain gets in the way, so this bond isomerises roughly an order of magnitude more slowly than the notorious Asp-Gly pair. The transient succinimide is also detectable, sitting 18 Da below the parent, so a mass spectrum can catch the intermediate even though it cannot see the product. The rate depends on pH and heat and has never been measured for this sequence.

The second hydrolytic route starts at the other end. The free N-terminal amine of Ala1 can fold back onto the Glu2 carbonyl and cut the chain by transamidation, releasing cyclo(Ala-Glu) near 200 Da and the dipeptide Asp-Arg near 290 Da. Diketopiperazine cleavage is fastest when residue 2 is proline or glycine and comparatively slow when it is glutamic acid, which is the case here. Unlike the isomerisation, this route is fully visible: the 489 Da signal falls and two new signals appear.

Charge state decides the handling. Five ionisable groups are present: the N-terminal amine (pKa about 8), the Arg guanidinium (about 12.5), the Glu gamma-carboxyl (about 4.3), the Asp beta-carboxyl (about 3.9) and the C-terminal carboxyl (about 3). At pH 7.4 the net charge is about -1, not positive, and the estimated isoelectric point of 4.1 to 4.3 is unpublished. Earlier product notes called the molecule cationic and warned about electrostatic adsorption to glass; three carboxylates outvote one guanidinium at neutral pH, so bulk attraction to glass is weak. The guanidinium still matters as a localised hydrogen-bond donor to silanolate sites, so modest surface loss stays plausible in dilute solutions. Type I borosilicate keeps that small, and one alanine side chain gives almost no drive toward polypropylene.

One excipient interaction is specific to the arginine. Guanidinium groups react with dicarbonyls such as methylglyoxal, which forms slowly in solutions containing reducing sugars, giving adducts on the residue that carries most of the molecule’s positive charge. That route is irrelevant if the fill contains no sugar and quietly relevant if it does, which is one more reason the unpublished excipient list is worth asking for.

No approved product containing AEDR exists anywhere to copy a formulation from. The compounds of this class are sold in Russia as oral capsules classed as dietary supplements, which settles nothing about an injectable solution.

What Is Known About Cardiogen Solution Stability?

Nothing measured has been published on cardiogen solution stability: a Crossref search in September 2026 returned no forced-degradation, shelf-life or formulation study for AEDR, and the one peer-reviewed cell paper does not state the concentration it used in medium.

The chemistry predicts the shape of the curve without giving its numbers. Cold storage near neutral pH slows both the succinimide route and the diketopiperazine route; warmth accelerates both; acid also cleaves the bonds flanking the aspartate. An unbuffered acetate salt in water sits near pH 4 to 5, close to the estimated isoelectric region. None of that is a rate constant, and cardiogen degradation in solution has not been followed for a single day, let alone across the weeks a multi-dose device stays in use.

A second risk sits outside chemistry. Every approved multi-dose peptide pen contains phenol or metacresol, because a solution punctured repeatedly over weeks faces microbial growth whatever its chemical stability. Whether this fill carries a preservative is not stated on the product record.

Concentration and Increment Arithmetic for the Cardiogen Pen

At 20mg in 3 ml the concentration is 20/3 mg/ml, which at a molecular weight of 489.49 g/mol is (20/3) divided by 489.49 moles per litre: a 20 mg fill gives 6.667 mg/ml and 13.6 mM, a 1 mg fill gives 0.333 mg/ml and 0.681 mM.

The smallest graduation, 0.01 ml, contains 20/300 mg, and 0.1 ml contains ten times that. At a 20 mg fill that is 66.7 micrograms per 0.01 ml, which is 136 nanomoles, and 667 micrograms per 0.1 ml.

The published work runs orders lower. The Khavinson group’s systematic review gives 2-200 ng/ml as the effective culture window for this family, which for a 489.49 Da molecule is 4 to 409 nM. Reaching 100 nM from a 13.6 mM fill needs a 136,000-fold dilution; from 0.681 mM, 6,800-fold. One 0.01 ml increment of a 20 mg fill diluted to 100 nM would make 1.36 litres of medium, so an actuation supplies an intermediate stock and never a working solution.

Does Cardiogen Come in a Pen?

Cardiogen does come in a pen: this preloaded 3 ml autoinjector holds AEDR in solution and sits in the catalogue alongside the lyophilized Cardiogen vial and the nasal spray presentation, so the live question is which of the three an experiment needs.

People searching “does cardiogen come in a pen” have usually seen the vial and want something that skips weighing and reconstitution. The general case for that is set out on the preloaded autoinjector category page. What is specific to cardiogen in pen form is that the fill pH, which is unpublished, governs the one degradation route that no routine purity check will report.

Cardiogen Pen vs Vial: Which Presentation Suits AEDR?

The cardiogen pen vs vial decision turns on isoaspartate, because a lyophilized powder is not doing this chemistry and a solution is, from the moment it is filled.

The pen suits work that draws repeatedly from one lot over weeks and needs each draw to match the last: a dose-response series built from a single stock across several days, or any protocol where weighing a milligram of hygroscopic acetate salt is the largest error in the procedure. It removes the balance, the diluent measurement and the dissolution step in one move.

The vial suits anything where the isomer ratio matters. Reconstituted powder gives a solution whose age is known to the hour, whose buffer and pH are selected rather than inherited, and which gives a same-day reference for judging an older device. Cardiogen solution vs lyophilized is, for this sequence, a question about how long the Asp3-Arg4 bond has sat in water at an unstated pH. The peptide pen versus vial article covers the trade-offs shared by every compound in the format; the cardiogen autoinjector vs vial version is unusual because the relevant change is one a mass-based certificate would not detect.

What the Product Record Does Not State

Four values are missing, and the first sets the rate of the chemistry described above.

Solution pH is not stated. Succinimide formation is pH-dependent and speeds up as the solution moves toward neutral and alkaline, while acid attacks the bonds flanking the aspartate instead, so there is no pH at which nothing happens, only a pH at which the least happens. An unbuffered acetate fill would sit near pH 4 to 5. Fifty microlitres and a calibrated meter settle the question on receipt.

The excipient system is not stated, and for this molecule that includes one specific question: whether any reducing sugar is present, given the guanidinium’s reactivity toward dicarbonyls. The salt form is not stated; the arginine retains a counter-ion even in the nominally free peptide, and trifluoroacetate is not inert in culture at millimolar stock concentrations. The fill date is not stated. Ask for it; the real-time stability data behind it does not exist for AEDR in any format.

Verifying the Cardiogen Pen and Detecting a Mass-Silent Change

Inspect the solution against a dark background before each draw: it should be clear, colourless and free of particulate, and since this tetrapeptide cannot aggregate, anything visible points to contamination or a precipitated excipient rather than to the peptide.

Analytically, the compound is awkward in one direction and easy in another. Absorbance at 280 nm is useless: with no tryptophan and no tyrosine there is nothing to absorb, so quantification has to work through the peptide bond at 205-215 nm, in practice reversed-phase HPLC at 214 nm. Mass spectrometry sees the parent at 490 Da protonated (489.218 Da monoisotopic), the diketopiperazine product cyclo(Ala-Glu) near 201 Da, the Asp-Arg dipeptide near 291 Da, and the succinimide intermediate 18 Da below the parent.

What mass spectrometry cannot see is the isoaspartyl form, which is why a chromatographic method matters more here than a spectrometric one. Alpha and beta isomers separate on a well-developed reversed-phase gradient as a shoulder or second peak at the parent mass, and the standard enzymatic approach uses protein isoaspartyl methyltransferase, which methylates isoaspartate specifically and turns an invisible isomer into a countable signal. A same-day solution reconstituted from the vial gives the comparator.

Cardiogen Pen Storage and Handling

Cardiogen pen storage is 2-8°C, protected from light and never frozen, with the device returned to the refrigerator between sessions, since temperature is the variable that drives both the succinimide route and the diketopiperazine route.

Light protection is the weakest of the storage instructions for this compound. With no aromatic residue and no disulfide, AEDR has no chromophore above roughly 220 nm and photodegradation is not a pathway available to it; the instruction guards against lamp heat and against photochemistry in whatever excipients are present. Temperature is where the attention belongs.

Freezing is prohibited for the sake of the hardware, not the peptide. A small, highly soluble tetrapeptide survives freeze-thaw, but 3 ml of solution expanding inside a sealed glass cartridge cracks glass and displaces elastomer plungers, and a cracked cartridge delivers wrong volumes without announcing it. Record the fill date, the date of first actuation and every excursion outside 2-8°C, because no in-use period has been established by anyone and that log is the only substitute for stability data. The peptide storage and stability guide covers the general principles.

What Does the AEDR Literature Actually Report?

One peer-reviewed cell study of this tetrapeptide exists, it was performed in mouse embryonic fibroblasts rather than in any cardiac cell, and it reports protein expression by immunocytochemistry rather than function.

Khavinson and colleagues (2012) reported that AEDR raised expression of the cytoskeletal proteins actin, tubulin and vimentin by 2 to 5-fold and the nuclear-matrix proteins lamin A and lamin C by 2 to 3-fold in cultured mouse embryonic fibroblasts. The abstract refers to the peptide’s previously reported cardioprotective activity, but the citation behind that phrase could not be retrieved, and no study in cardiomyocytes, isolated hearts, infarction, heart-failure or hypertension models was found in the peer-reviewed literature.

The remaining published material is computational. A 2023 docking paper places AEDR at the LAT1 transporter with a score of -35.35 kcal/mol, at LAT2 with -27.54 and at PEPT1 with -27.50 kcal/mol; those are calculated values, and no binding to any transporter has been measured. The group’s 2016 docking study of nineteen peptide-DNA complexes lists AED, AEDL, KE, EDP, KEDW and EDL, and does not include AEDR at all.

The name-to-sequence link is worth stating plainly. The trade name Cardiogen does not appear in the 2012 abstract or in any other peer-reviewed abstract reachable during this research, so the mapping to AEDR rests on the institute’s own product literature and on secondary sources. The background article on this compound covers that history, and the bioregulator research overview places it beside better-studied members of the family. Structurally AEDR is the Cartalax tripeptide AED plus one arginine, and the same AED core appears in Epitalon (AEDG), Bronchogen (AEDL) and Cortagen (AEDP).

What is absent: no human evidence of any kind, no controlled trial, no case series, no registered study; no verifiable animal experiment; no pharmacokinetics; no toxicology; no dose-response; and no replication outside the Khavinson institute. The institute’s own 2014 review of clinical results for peptide bioregulators covers seven other preparations and does not mention Cardiogen.

What Is the Safety and Regulatory Position?

No safety study of AEDR exists in any species, and no regulator has approved a product containing it: not the FDA, EMA, PMDA, TGA or Health Canada, and the compound does not appear in the FDA Orange Book.

Russian marketing is as a dietary supplement rather than a medicine, a status this research did not verify against the Russian register. The compound is not on the FDA section 503A bulk-substance list and not in Category 1 or Category 2 of the interim lists (FDA page updated 22 April 2026), is not a component of any approved drug and has no USP monograph, so no lawful basis exists for compounding it from bulk in the United States. Nothing under this name was located on the WADA Prohibited List; because the 2026 document was unreachable, that finding is unconfirmed.

No adverse finding has been reported, for the plain reason that no study capable of finding one has been run. Cardiac claims of any kind have a single fibroblast immunostaining paper behind them and nothing else, and nothing in the published record describes what this reagent does after injection into any organism.

Published Literature

The entries below concern the tetrapeptide AEDR and the peptide family it belongs to; nothing has been published on this delivery format.

1. Khavinson VK, Lin’kova NS, Polyakova VO, et al. Tetrapeptide H-Ala-Glu-Asp-Arg-OH Stimulates Expression of Cytoskeletal and Nuclear Matrix Proteins. Bulletin of Experimental Biology and Medicine. 2012;153(4):559-562. DOI: 10.1007/s10517-012-1766-9. PMID: 22977870
2. Khavinson VK, Linkova NS, Rudskoy AI, et al. Feasibility of Transport of 26 Biologically Active Ultrashort Peptides via LAT and PEPT Family Transporters. Biomolecules. 2023;13(3):552. DOI: 10.3390/biom13030552. PMID: 36979488
3. Khavinson VK, Popovich IG, Linkova NS, et al. Peptide Regulation of Gene Expression: A Systematic Review. Molecules. 2021;26(22):7053. DOI: 10.3390/molecules26227053. PMID: 34834147
4. Khavinson VK, Lin’kova NS, Tarnovskaya SI. Short Peptides Regulate Gene Expression. Bulletin of Experimental Biology and Medicine. 2016;162(2):288-292. DOI: 10.1007/s10517-016-3596-7
5. Khavinson VK, Kuznik BI, Ryzhak GA. Peptide bioregulators: A new class of geroprotectors, report 2. The results of clinical trials. Advances in Gerontology. 2014;4(4):346-361. DOI: 10.1134/S2079057014040122
6. Anisimov VN, Khavinson VK. Peptide bioregulation of aging: results and prospects. Biogerontology. 2010;11(2):139-149. DOI: 10.1007/s10522-009-9249-8
7. Khavinson VK, Linkova NS, Polyakova VO, et al. Peptides Tissue-Specifically Stimulate Cell Differentiation during Their Aging. Bulletin of Experimental Biology and Medicine. 2012;153(1):148-151. DOI: 10.1007/s10517-012-1664-1

Frequently Asked Questions