Khavinson Bioregulators: What the Evidence Actually Shows
Vilon, Vesugen, Livagen, Testagen and Epitalon are near-identical peptides sold for different organs. We checked every claim against the primary literature.
TL;DR
The family: Vilon (Lys-Glu), Vesugen (Lys-Glu-Asp), Livagen (Lys-Glu-Asp-Ala), Testagen (Lys-Glu-Asp-Gly) and Epitalon (Ala-Glu-Asp-Gly) are 2 to 4 amino acids long and share almost the same core sequence. Each is marketed for a completely different organ.
The citation problem: The human mortality study everyone cites for these peptides (PMID 14523363) did not test them. It tested Thymalin and Epithalamin, two crude animal tissue extracts.
Vilon specifically: No randomised controlled human trial. We could not find one.
The mechanism: Sequence-specific, organ-targeted gene activation has never been confirmed by a laboratory independent of Khavinson's own institute.
What we stock, stated honestly: Of this whole group we carry only Epitalon and Thymalin, and their evidence is not the same kind. Thymalin has non-blinded human cohort data. Epitalon has cell-culture work, including one independent replication. Neither has a randomised controlled human trial. Details below, including the part that cuts against us.
Every few months a new bioregulator makes the rounds. The pitch is always the same: a tiny peptide, two to four amino acids, that walks into the nucleus, binds DNA at a specific promoter and switches a sleeping organ back on. Vilon for the immune system. Vesugen for blood vessels. Livagen for the liver. Testagen for the testes.
It is a genuinely interesting hypothesis. It is also a hypothesis that has been repeated so many times, by so many vendors, that the repetition itself has started to look like evidence.
So we went back to the primary literature and checked. Not the vendor pages, not the newsletters, not the secondary summaries that quote other secondary summaries. PubMed, PubChem, the FDA docket. What follows is what actually holds up, and what does not. Including where that verdict is uncomfortable for our own catalogue.
The family, and why the sequences should make you suspicious
Vladimir Khavinson led the St. Petersburg Institute of Bioregulation and Gerontology and spent decades developing what he called short peptide bioregulators. He died on 6 January 2024, aged 77. Nearly all research and marketing on these compounds still traces back to his institute.
Here is the family, with the sequences confirmed against PubChem:
- Sequence
- Lys-Glu (KE)
- Length
- 2
- Marketed for
- Thymus, immune system
- Sequence
- Lys-Glu-Asp (KED)
- Length
- 3
- Marketed for
- Vascular endothelium
- Sequence
- Lys-Glu-Asp-Ala (KEDA)
- Length
- 4
- Marketed for
- Liver
- Sequence
- Lys-Glu-Asp-Gly (KEDG)
- Length
- 4
- Marketed for
- Testes
- Sequence
- Ala-Glu-Asp-Gly (AEDG)
- Length
- 4
- Marketed for
- Pineal gland, telomeres
Look at the middle column. Vesugen is Vilon plus one aspartic acid. Livagen is Vesugen plus one alanine. Testagen is Vesugen plus one glycine, differing from Livagen by a single methyl group.
These are not five different drugs. They are one dipeptide with a few residues bolted on. Yet each is sold as though it carries a postcode for a specific organ.
And yes, this argument cuts against the one we sell
Look at the table again. Epitalon is Testagen with a single substitution, lysine swapped for alanine. Structurally it is no more special than the rest of the family, and we are not going to pretend otherwise.
The only thing that separates Epitalon is that somebody outside Khavinson's institute has finally tested it, and even that was done in cells rather than in people. Evidence is the reason it is in our catalogue. The sequence is not. If the same independent work were done on Vilon tomorrow, we would look at Vilon again.
Why a molecular biologist would raise an eyebrow
Sequence-specific DNA recognition normally requires a folded protein domain with a defined three-dimensional binding surface, on the scale of tens of amino acids. A dipeptide has no fold. The claim that adding one residue to a two-amino-acid chain redirects it from the thymus to the liver is not impossible, but it is an extraordinary claim, and extraordinary claims need more than one institute publishing on itself for forty years.
The citation almost everyone gets wrong
This is the part that matters most, and it is the reason we wrote this article.
If you search for human evidence on Vilon or Epitalon, you will land on the same paper again and again: Khavinson and Morozov, "Peptides of pineal gland and thymus prolong human life", Neuroendocrinology Letters 2003, PMID 14523363. It is cited as proof that these peptides reduce mortality in elderly people.
We pulled the paper. Here is what it actually did.
It followed 266 elderly people for 6 to 8 years, with treatment given during the first 2 to 3 years, across two institutes: one in St. Petersburg and the Institute of Gerontology in Kiev. There were four arms. Reported mortality reduction versus untreated controls was 2.0 to 2.1-fold in one treatment arm, 1.6 to 1.8-fold in the second, 2.5-fold with both combined, and 4.1-fold when the combined course was repeated annually for six years.
Those are real numbers from a real, peer-reviewed paper. They also come from a study that was not blinded and had no placebo arm, which is the ceiling on how much weight they can carry.
And the substances tested were Thymalin and Epithalamin.
Thymalin and Epithalamin are not Vilon and Epitalon
Thymalin is a polypeptide complex extracted from calf thymus tissue, a crude mixture of many peptide species in the 1 to 6 kDa range. Epithalamin is the equivalent crude extract from the pineal gland.
Vilon (Lys-Glu) and Epitalon (Ala-Glu-Asp-Gly) are chemically defined synthetic peptides. They are different substances.
The 2003 mortality data belongs to the extracts. Citing it as evidence for the synthetic peptides is a substance misidentification, not a shortcut. It is the single most widespread error in bioregulator marketing, and once you know it is there, you will see it everywhere.
A note on the three similar names
Epitalon and Epithalon are two spellings of the same synthetic tetrapeptide (Ala-Glu-Asp-Gly).
Epithalamin is not a spelling variant. It is the crude pineal extract, a different substance entirely.
That one letter is doing a lot of work, and a great deal of confusion in this field lives in exactly that gap.
The confusion is understandable. Both came out of the same institute, the names sound related, and Epitalon was in fact modelled on Epithalamin. But "modelled on" is not "the same as", and a study of a tissue extract cannot be quietly upgraded into a study of a synthetic tetrapeptide.
What the Vilon evidence actually is
Strip away the misattributed mortality data and what remains for Vilon specifically?
Cell culture, ex vivo. Lezhava and colleagues cultured lymphocytes from elderly donors and reported that Vilon decondensed heterochromatin in those cells (Biogerontology 2004, PMID 15105581). This is a real, specific, peer-reviewed finding. It is also not independent: Khavinson is a co-author. And it is human cells in a dish, which tells you nothing about whether the peptide survives administration, reaches a target cell, or does anything measurable in a living organism.
Rodents. Khavinson's group reported that Vilon aided recovery of radiosensitive organs in irradiated rats (Bulletin of Experimental Biology and Medicine 2001, PMID 11427924). The paper is real. Vendor pages routinely attach a precise figure to it, a rise in thymocyte proliferation from 26 percent to 37 percent. We could not find that figure in the paper or in any primary source. Treat it as unverified false precision.
Humans. There is no randomised controlled trial of Vilon that we could find. We searched PubMed and the trial registries and came up with nothing.
About that '2022 placebo-controlled trial'
A claim circulating right now says a 2022 randomised, placebo-controlled study of Vilon with 520 participants exists, from Khavinson's own institute.
We could not find it. The only PubMed-indexed 2022 paper involving Vilon (PMID 35408963) is an in vitro study on the THP-1 monocyte cell line. That is a dish of cells, not 520 people.
Until somebody produces a citation, treat this trial as not existing.
There is a quiet irony in that 2022 cell study. It was a collaboration with a group in Italy, and it tested Vilon, the supposedly thymus-specific peptide, in a monocyte line. The paper reports activity there. A peptide sold as thymus-specific showing activity in a non-thymic cell line does not help the organ-specificity case. It is a cell-culture result and should not be pushed further than that, but it certainly does not support the postcode story.
The tissue-specificity claim has never been independently confirmed
This is the load-bearing scientific claim of the entire bioregulator concept. If these peptides do not achieve sequence-specific, organ-targeted gene activation, then the whole "one peptide per organ" catalogue collapses into a family of near-identical molecules with vague, overlapping effects.
So we looked hard for independent confirmation.
The foundational DNA-binding work (Biochemistry Moscow 2011, PMID 22117547) used a fluorescence-quenching assay, not a structural method, and measured affinity for short repeat motifs rather than tissue-specific promoters. Khavinson is a co-author. The chromatin paper is co-authored by Khavinson. The 2022 Italian collaboration is co-authored by Khavinson. Even the systematic review of the mechanism (Molecules 2021, PMID 34834147) is written entirely by his own institute, which means it cannot serve as independent validation of itself.
Every paper we could verify that reports sequence-specific, tissue-targeted gene activation for these peptides in animal or human tissue lists Khavinson as an author, or came out of his institute. We found no fully independent laboratory that has replicated organ-targeted gene activation.
We also found no failed replication, no critical rebuttal, no PubPeer thread. The independent scientific community has not refuted this work. It has simply not engaged with it. That is a different thing, and it is worth being honest about which one it is.
How to read any bioregulator claim in thirty seconds
Four questions strip most of the noise out:
- Which substance was actually tested? An extract (Thymalin, Epithalamin) is not a synthetic peptide (Vilon, Epitalon).
- Who is on the author list? If the inventor's institute appears on every paper, you have one lineage, not a consensus.
- What was the design? Cell culture and open-label cohorts are not randomised controlled trials, and non-blinded is not blinded.
- Does the identifier check out? See below. It often does not.
A small detail that tells you how careless this corner of the market is
While verifying the sequences, we checked the CAS registry numbers that vendors publish for each compound.
The CAS number widely listed for Livagen across peptide shops and reference sites is 195875-84-4.
That CAS number does not belong to Livagen. It belongs to Tesofensine, an experimental anti-obesity compound with no relationship to this peptide family whatsoever. PubChem's actual record for the Lys-Glu-Asp-Ala sequence carries no CAS number at all.
Nobody checked. One site published a wrong identifier, and the rest of the industry copied it.
We are pointing this out because it is a clean illustration of the underlying problem. If a chemical identifier, the single most checkable fact about a compound, can propagate through an entire market unverified, then a paraphrased claim about a twenty-year-old Russian mortality study can too. And it has.
Testagen is a similar story. Search PubMed for it and you get essentially nothing on the compound itself. Its "targets the testes" positioning is an extrapolation from the sequence pattern, not a demonstrated finding.
The two Khavinson-lineage compounds we do stock, and what we will not claim
We carry Epitalon and Thymalin. We do not carry Vilon, Vesugen, Livagen or Testagen, and this article is a large part of the reason why. Here is the honest evidence position on the two we do sell.
Tetrapeptide (Ala-Glu-Asp-Gly) that activates telomerase, the enzyme responsible for maintaining telomere length. One of the most studied peptides in longevity research, developed by Prof. Khavinson at the St. Petersburg Institute of Bioregulation.
Thymus-derived immune peptide developed by Prof. Khavinson. Restores T-cell function and thymic activity that naturally decline with age. Over 40 years of clinical use in Russia for immune support and anti-aging research.
Epitalon (Ala-Glu-Asp-Gly)
The headline telomerase claim originates in a single in vitro study by the compound's own inventor (Bulletin of Experimental Biology and Medicine 2003, PMID 12937682), in which telomerase-negative human fetal fibroblasts kept dividing past the Hayflick limit.
It does now have one genuinely independent in vitro result. A 2025 study from Brunel University London (Biogerontology 2025) found dose-dependent telomere lengthening and hTERT upregulation in cultured normal human cells, with no Khavinson affiliation. This is cell culture, not a human trial, but it is the first piece of this programme replicated outside the founding institute, and we are glad it exists.
The part of the independent study that vendors leave out
The same Brunel study also tested cancer cell lines. There, telomerase activity was not significantly increased despite hTERT going up, and the peptide instead activated the ALT pathway, an alternative telomere-maintenance mechanism associated with cancer biology.
That is not a footnote. An independent replication that partially supports the mechanism while raising a cancer-adjacent question is a mixed result, and anyone selling this compound owes you both halves of it.
Beyond that: the human mortality data routinely attributed to Epitalon is, as covered above, actually Epithalamin extract data. Rodent work from the Khavinson and Anisimov collaboration reported reduced spontaneous tumour incidence in mice, but the results are strain-dependent and heterogeneous, with at least one rat study showing reduced tumour incidence and no lifespan gain (PMID 11227856). The melatonin claims are internally contradicted, with an independent study on perifused rat pineal glands finding no effect on melatonin secretion.
So the honest one-line summary for Epitalon is: cell-culture evidence with one independent in vitro replication that cuts both ways, animal data from a single research lineage, and no randomised controlled human trial.
Thymalin
Two things must be said plainly.
First, Thymalin is not a defined peptide at all. It is a polypeptide complex extracted from calf thymus, registered as a pharmaceutical in the USSR in 1982. It is the substance that actually appears in the 2003 mortality paper, which makes its human evidence base thicker than Vilon's, but that evidence is still non-blinded, non-placebo-controlled, single-lineage cohort work.
And because Thymalin is a mixture rather than a single defined molecule, any given preparation is not automatically identical to the one used in that study. We supply research material. We make no efficacy claim from that paper, and neither should anybody else.
Second, and this trips up a lot of people:
Thymalin is not Thymosin Alpha-1
Thymalin (a Soviet-era polypeptide complex from calf thymus, chemically undefined) and Thymosin Alpha-1 (a chemically defined 28-amino-acid peptide, marketed as the licensed medicine Zadaxin) are different substances that get confused because both are thymus-derived immunomodulators with similar names.
The substantial randomised controlled trial evidence base belongs to Thymosin Alpha-1, and it was generated with a licensed pharmaceutical product in clinical settings. It must not be cited as evidence for Thymalin, and we do not present it as evidence for any material we supply.
Thymosin Alpha-1 is a separate, chemically defined compound, and we list it separately.
Synthetic 28-amino-acid immunomodulatory peptide. Approved as Zadaxin in 35+ countries for chronic hepatitis B and C. Studied in 30+ trials across 11,000+ subjects for immune modulation via TLR2/9 dendritic cell signaling.
We have written the direct comparisons up separately: Epitalon vs Thymalin and Thymalin vs Thymosin Alpha-1.
Where these compounds stand with regulators
Epitalon is on the agenda of the FDA Pharmacy Compounding Advisory Committee meeting scheduled for 23 and 24 July 2026 (docket FDA-2025-N-6895), as a candidate for the 503A bulks list under the nominated use "healthy aging". A PCAC recommendation is advisory. The FDA still has to complete rulemaking before anything is actually added, so Epitalon is not on the adopted 503A list, and will not be on it simply because the committee meets.
The FDA's own safety narrative on it is worth quoting, because it is the kind of thing marketing copy skips: compounded drugs containing epitalon may pose a risk of immunogenicity for certain routes of administration, due to the potential for aggregation and peptide-related impurities.
Vilon, by contrast, has no FDA regulatory footprint at all. No nomination, no safety notice, nothing. It is simply not on the map.
We have written up the upcoming July 2026 hearing and what it means from an EU perspective here: FDA PCAC July 2026.
Mitochondrial function, NAD+ metabolism, telomere maintenance
Khavinson-lineage compounds we stock
Tetrapeptide (Ala-Glu-Asp-Gly) that activates telomerase, the enzyme responsible for maintaining telomere length. One of the most studied peptides in longevity research, developed by Prof. Khavinson at the St. Petersburg Institute of Bioregulation.
Thymus-derived immune peptide developed by Prof. Khavinson. Restores T-cell function and thymic activity that naturally decline with age. Over 40 years of clinical use in Russia for immune support and anti-aging research.
Other longevity compounds we stock
Synthetic 28-amino-acid immunomodulatory peptide. Approved as Zadaxin in 35+ countries for chronic hepatitis B and C. Studied in 30+ trials across 11,000+ subjects for immune modulation via TLR2/9 dendritic cell signaling.
Mitochondria-targeted tetrapeptide (Elamipretide) that stabilizes cardiolipin and prevents ROS formation at the source.
Mitochondrial-derived signaling peptide (16 amino acids) that mimics the effects of exercise at the cellular level. Activates AMPK, improves glucose uptake, and enhances fat metabolism - a key tool in metabolic and longevity research.
So is any of this real?
We want to end honestly rather than tidily, because a clean verdict here would be its own kind of dishonesty.
The Khavinson programme is not a scam. The papers exist, they are peer-reviewed, and some of the findings are specific and interesting. Chromatin decondensation in lymphocytes from very old donors is a real result. The 2003 mortality cohort is a real study with real numbers, even if it was neither blinded nor placebo-controlled and even if it tested extracts rather than peptides. A short peptide interacting with DNA is a legitimate, testable idea, and one independent Western lab has now partially replicated a piece of it in cells.
But the marketing has run several hundred metres ahead of the science, and it has done so by blurring exactly the distinctions that matter: extract versus synthetic peptide, cell culture versus living organism, open-label cohort versus randomised trial, one institute publishing on itself versus independent confirmation.
Our position, stated without flattering ourselves: Epitalon and Thymalin are the only two compounds discussed here that we stock, and neither has a randomised controlled human trial behind it. What separates them from Vilon, Vesugen, Livagen and Testagen is not a better sequence. It is that they have been tested at all, Thymalin in a human cohort and Epitalon now once outside its founding institute. That is a low bar. We would rather tell you exactly where that bar sits than sell you a story about a dipeptide with a postcode.
Questions about these research compounds
Our support team answers questions on sourcing, batch testing and Certificates of Analysis. Every batch ships with the third-party Certificate of Analysis supplied by its manufacturer. Live chat on peptidesdirect.io or email support.
FAQ
Sources
- Khavinson VK, Morozov VG. Peptides of pineal gland and thymus prolong human life. Neuroendocrinology Letters 2003;24(3-4):233-240. PMID 14523363
- Khavinson VK, Bondarev IE, Butyugov AA. Bulletin of Experimental Biology and Medicine 2003;135(6):590-592. PMID 12937682 (Epitalon, telomerase, in vitro)
- Lezhava T, Khavinson V, et al. Biogerontology 2004. PMID 15105581 (Vilon, chromatin, ex vivo)
- Khavinson VK, et al. Bulletin of Experimental Biology and Medicine 2001. PMID 11427924 (Vilon, irradiated rats)
- Fedoreyeva LI, Khavinson VKh, Vanyushin BF, et al. Biochemistry (Moscow) 2011. PMID 22117547 (fluorescence-quenching binding assay, short repeat motifs)
- Avolio F, Khavinson VK, et al. International Journal of Molecular Sciences 2022. PMID 35408963 (THP-1 monocyte cell line, in vitro)
- Khavinson V, et al. Molecules 2021. PMID 34834147 (systematic review, authored by the founding institute)
- Anisimov VN, et al. PMID 11227856 (rodent lifespan and tumour incidence)
- Al-Dulaimi S, et al. Biogerontology 2025. DOI 10.1007/s10522-025-10315-x (Brunel University London, independent in vitro replication)
- Araj SK, et al. International Journal of Molecular Sciences 2025;26(6):2691 (independent review, including the perifused pineal finding of no melatonin effect)
- FDA, Pharmacy Compounding Advisory Committee, Notice of Meeting, Docket FDA-2025-N-6895, Federal Register, 16 April 2026
- PubChem compound records for Lys-Glu, Lys-Glu-Asp, Lys-Glu-Asp-Ala, Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly
Research use only. The compounds discussed in this article are supplied for laboratory research purposes and are not medicines. They are not approved by the FDA or the EMA for any indication and are not intended for administration to humans or animals. Nothing here is medical advice.
Research context for English-speaking buyers
Most of our English-speaking customers ship to the UK, Ireland, Malta or other English-as-second-language EU territories. The regulatory picture differs per country.
- Relevant authorities
- MHRA (UK, post-Brexit), HPRA (Ireland, EU-aligned), FDA Section 503A bulks list (US, restricted Cat 2 status of several peptides as of 2026)
- Customs and VAT
- EU shipments include 19% VAT; UK shipments after Brexit are now extra-EU and may attract UK VAT plus a handling fee at import
- Typical shipping window
- EU 2-4 working days, UK 4-7 working days, other international 7-14 working days, depending on customs
Research-grade peptides shipped from our EU warehouse are sold for laboratory use only and are not authorised for human or veterinary therapeutic application in any of the destination jurisdictions. US customers should be aware that the FDA Section 503A bulks list classification (and the April 2026 reclassification of twelve compounds) only governs compounding pharmacies, not direct-to-researcher imports for non-clinical work. UK buyers should declare the consignment on import and may be asked for a research justification by HMRC. We provide a CoA per batch identified by colour code rather than serial number; customs sometimes asks for this document when clearing the parcel.