Livagen
A synthetic tetrapeptide (Lys-Glu-Asp-Ala) from the Khavinson bioregulator programme, studied almost entirely as a chromatin-activating agent in lymphocytes taken from very old donors. Its sequence is widely printed online as KEDD; the primary literature and the PubChem record both say KEDA, and that discrepancy is the most useful thing this entry records.
Lys-Glu-Asp-Ala · 4 residues · 461.47 Da (computed)
Lysine at position 1 (terminal).
Bioregulator context
Target tissue: not established — the located work uses human lymphocytes, serum and rat gut; no source names a source tissue (unknown)
That short synthetic peptides of this family act as tissue-specific regulators of gene activity, and that Livagen in particular reverses the chromatin condensation of ageing — activating ribosomal genes, decondensing pericentromeric heterochromatin, and releasing genes that age-related packing had silenced in cells from people in their eighties.
Proposed to reach the nucleus and act on chromatin and DNA directly, de-heterochromatinising densely packed regions and reactivating repressed genes. What has actually been shown is a set of cytogenetic changes in cultured lymphocytes after peptide exposure; the step from that observation to sequence-specific gene regulation in a living body is asserted rather than demonstrated.
Mechanism
Claimed
Reactivates genes silenced by age-related chromatin condensation, restoring cellular function in the elderly.
Actually established
Cultured lymphocytes from donors in their seventies and eighties showed ribosomal-gene activation and decondensation of structural heterochromatin after exposure. That is a real, repeatedly reported cytogenetic observation. It has no established clinical meaning, was produced entirely inside one collaboration, and has never been tested in a living person.
How good is the evidence
PubMed indexed 19 records mentioning Livagen when checked on 2026-08-06, and not one is a human trial. The recurring finding is cytogenetic: lymphocytes from donors aged 72-88, exposed to the peptide in culture, show ribosomal-gene activation and heterochromatin decondensation. It is reported more than once, but by the same St Petersburg / Tbilisi collaboration each time, so repetition here is not replication. A separate in-vitro paper reports inhibition of enkephalin-degrading enzymes in human serum while finding no interaction with opioid receptors — the clearest instance on this page of a source pointing two ways at once. One rat study of digestive-enzyme activity exists (PMID 16075683); only its citation metadata was retrieved, so no claim on this page rests on it.
Khavinson or his collaborator V.V. Malinin is an author on four of the five studies listed here. The Tbilisi cytogenetics group (Lezhava, Dzhokhadze) that produced the later chromatin work co-authored the original 2002 paper with Khavinson, so the apparent second look at the finding comes from inside the same collaboration.
Claims, one at a time
Each claim carries its own evidence tier. A compound is never simply "well studied" — some of its claims may be, others not at all.
| Claim | Verdict | Evidence | Basis |
|---|---|---|---|
| Livagen's sequence is Lys-Glu-Asp-Asp (KEDD) | contradicted | Anecdote | KEDD circulates widely in secondary and social-media sources. PMID 12942748 states Lys-Glu-Asp-Ala, and the molecular formula computed from KEDA (C18H31N5O9) matches PubChem CID 87919683 exactly, while KEDD does not. The commonly repeated sequence is wrong. |
| Reverses age-related chromatin condensation and reactivates silenced genes in cells from elderly people | supported | In vitro | Two papers report ribosomal-gene activation and decondensation of pericentromeric structural heterochromatin in lymphocytes from donors aged 75-88 after exposure to the peptide. Supported at tier E means supported in a dish: the material is cultured leukocytes, the endpoints are cytogenetic measures with no established clinical correlate, the compound's developer is an author on both, and no group outside that collaboration has looked. Nothing about how an elderly person would function follows from it. |
| Acts on the endogenous opioid system | mixed | In vitro | One paper reports that Livagen inhibits enkephalin-degrading enzymes in human serum in vitro, with an IC50 of 20 microM — more potent in that assay than puromycin or leupeptin. The same paper found no interaction at all between the peptide and mu- or delta-opioid receptors in a rat brain membrane fraction. A single source therefore supports half the claim and contradicts the mechanism usually attached to it, and 20 microM in a serum assay has no established in-vivo equivalent. |
| Corrects the radiation-induced adaptive response in cells from old people | supported | In vitro | In lymphocytes from individuals aged 72-86 exposed to low-dose gamma irradiation and then to copper chloride, 'corrective activity of Livagen was observed'. That sentence is the entire result as the abstract states it: no effect size, no statistics, no dose, and no comparison quantity. It is recorded here as supported at tier E only in the sense that a source reports it; a reader should treat it as an observation, not a measurement. |
| Is a geroprotector that slows ageing in people | untested | Anecdote | No human study of any design was found in the indexed literature — not a trial, not a cohort, not a case series. The 19 PubMed records are cell, tissue and rodent work. The claim circulates through the compound's membership in the bioregulator catalogue rather than through any source that tested it. |
The studies themselves
| Study | Design | Subjects | Quality |
|---|---|---|---|
Effects of Livagen peptide on chromatin activation in lymphocytes from old people
Khavinson VKh, Lezhava TA, Monaselidze JG, Dzhokhadze TA, Dvalishvili NA, Bablishvili NK, Ryadnova IY · Bulletin of experimental biology and medicine · 2002
PMID 12533768
|
in_vitro / cell_culture | — Lymphocytes from elderly donors; group size not stated in the abstract | In vitro
risk of bias: high
authored by the developer |
Effects of short peptides on lymphocyte chromatin in senile subjects
Khavinson VKh, Lezhava TA, Malinin VV · Bulletin of experimental biology and medicine · 2004
PMID 15085253
|
in_vitro / cell_culture | — Leukocytes from subjects aged 75-88; five peptides compared, Livagen among them | In vitro
risk of bias: high
authored by the developer |
[Effect of new peptide bioregulators livagen and epitalon on enkephalin-degrading enzymes in human serum]
Kost NV, Sokolov OIu, Gabaeva MV, Zolotarev IuA, Malinin VV, Khavinson VKh · Izvestiia Akademii nauk. Seriia biologicheskaia · 2003
PMID 12942748
ru |
in_vitro / mixed | — Human serum enzyme assays and rat brain membrane fractions, in vitro | In vitro
risk of bias: high
authored by the developer |
[Effect of peptide Livagen on activity of digestive enzymes in gastrointestinal tract and non-digestive organs in rats of different ages]
Timofeeva NM, Khavinson VKh, Malinin VV, Nikitina AA, Egorova VV · Advances in gerontology = Uspekhi gerontologii · 2005
PMID 16075683
ru |
animal_uncontrolled / rat | — Rats of different ages | Animal
risk of bias: unclear
authored by the developer |
[Variability of radiation-induced adaptive response in old age individuals and their correction by Peptide bioregulator -Livagen]
Dzhokhadze TA, Buadze TZh, Dvalishvili NA, Lezhava TA · Georgian medical news · 2007
PMID 17921545
ru |
in_vitro / cell_culture | — PHA-stimulated lymphocytes from individuals aged 72-86, with 30-40-year-old donors as controls | In vitro
risk of bias: high
|
- The sequence rests on one paper plus a formula match; no second independent source has been read to confirm it.
- Whether material sold as Livagen is in fact Lys-Glu-Asp-Ala cannot be checked by a buyer — no vendor publishes an identity assay.
- Whether PubChem CID 87919683 is in fact the substance sold as Livagen has not been confirmed against a primary source. A name match is not an identity check — the same lookup for Thymalin returned an entirely different molecule.
- No human study of any design exists in the indexed literature: no trial, no cohort, no case series, no pharmacokinetics.
- No source located here names the tissue this peptide is derived from or claimed to act on, which is unusual for a compound in this family and is why targetTissue and targetOrganSystem are left unresolved.
- The one whole-animal study (PMID 16075683) has not been read beyond its citation, so what it found is not known here.
- No safety data of any kind was located — no adverse-event report, no toxicology, no exposure duration.
- No dose is recorded on any study on this page, because no full text has been read.
What people actually report
- requests for personal experiences
- discussion in post-finasteride syndrome and anhedonia communities
- claims about DNA-related mechanisms
- questions about combining Livagen with other peptides
What people keep asking
- What experiences have people had with Livagen?
- Why are people discussing Livagen for post-finasteride symptoms or anhedonia?
- What evidence is cited for Livagen affecting DNA?
- How does Livagen fit alongside other peptides?