Khavinson bioregulators: a critical guide

Two generations of one idea

The idea behind Vladimir Khavinson's program, developed at the St. Petersburg Institute of Bioregulation and Gerontology, is that each tissue has its own regulatory peptides, and that giving them back can restore function as the body ages. The first generation was extracts. Thymalin Low is a polypeptide mixture from calf thymus, not a single molecule ¹; cortexin, from brain tissue, and epithalamin, from the pineal gland, followed the same pattern ¹.

The second generation reduced each extract to a short synthetic peptide said to carry its activity. Epitalon Low (Ala-Glu-Asp-Gly) was designed from the composition of epithalamin, according to a 2025 review ². Others in the family, by the sequences in our records, include vilon (Lys-Glu), pinealon (Glu-Asp-Arg), cortagen (Ala-Glu-Asp-Pro), livagen (Lys-Glu-Asp-Ala), vesugen (Lys-Glu-Asp), chonluten (Glu-Asp-Gly) and bronchogen (Ala-Glu-Asp-Leu) ¹. Thymogen Low (Glu-Trp), a Soviet immunomodulator, is a cousin of the program rather than a product of it ¹. Most are only two to four amino acids long, which makes them among the shortest compounds anyone markets as peptide drugs.

What is registered, and where (as of October 2, 2026)

Registration differs sharply between the two generations. Thymalin is approved as a medicine in Russia, and cortexin is a prescription medicine in Russia and several other former Soviet states for neurological conditions ¹. Thymogen has been used in Russia as an immunomodulating drug ¹. The short synthetic peptides are, by our records, marketed in Russia as bioregulator supplements, and sold elsewhere through gray-market research-chemical catalogues ¹. None of them, extract or peptide, is approved by the FDA, and none appears in the EMA's register in our records ¹. Epitalon is the one the FDA has looked at closely, through its compounding committee in 2026, as our epitalon article describes.

Who wrote the evidence

We counted the PubMed record on October 2, 2026, searching titles and abstracts for each name and then for the same records with Khavinson as an author ³. Across eleven names there were 652 records, and Khavinson was an author on 185 of them. The share varies in a telling way. For the synthetic short peptides it is high: 62% of the 120 epitalon records, 63% of the 62 vilon records and 9 of the 13 cortagen records. For the older extracts it is much lower: 32% of the 234 thymalin records and 6% of the 202 cortexin records, because those were used and studied as medicines by many Russian clinicians ³.

The count understates the concentration, because it does not include papers by the program's long-standing collaborators without Khavinson's name. It also overstates how much there is to read: many records are in Russian-language journals with brief English abstracts. A literature that comes overwhelmingly from the developer's own group has not been tested the way science normally is, by independent groups trying to reproduce it.

What kind of evidence it is

The same search, restricted to records PubMed indexes as randomised controlled trials, found 20 across all eleven names, 2 of them with Khavinson as an author, and just 1 for the synthetic short peptides other than thymogen ³. Much of the human literature is case series and open studies. A thymalin report in Parkinson's disease described improvement in 15 patients assessed before and after treatment, with no control group ⁴; a thymogen report in 46 women with pelvic infections described a marked clinical effect with no comparison arm ⁵. There are exceptions, such as a randomised, placebo-controlled study of intranasal thymogen before tumour surgery in older patients ⁶, and a 2022 comparison in severe COVID-19 in which hospital mortality was 20.6% with thymalin, 28.4% with tocilizumab and 40.9% with standard care ⁷, though the summary we read does not describe how patients were allocated.

The most quoted human result for the family, 28% fewer deaths over 12 years, came from epithalamin, the extract, in elderly heart patients, not from the synthetic epitalon sold today ⁸. And the famous telomere finding was made in cultured fibroblasts ⁹.

What is actually sold

Outside Russia, bioregulators are sold mainly as capsules marketed under brand-like names and as lyophilised research-chemical vials. Neither route comes with the evidence or quality controls of a registered medicine, and a capsule of a two-amino-acid peptide raises a basic question no study we found has answered: how much of it survives digestion intact. The registered Russian extracts are not the same products as the synthetic peptides sold online under related names. Anyone considering them should treat the claims as unconfirmed by independent research and speak with a doctor first.

Frequently asked questions

What are bioregulator peptides?

Peptides from Vladimir Khavinson's Russian program, in two forms: extracts of animal glands, such as thymalin, and synthetic peptides of two to four amino acids designed from them, such as epitalon, vilon and pinealon.

Are Khavinson peptides approved?

Some extracts, such as thymalin and cortexin, are registered medicines in Russia. The short synthetic peptides are sold there mainly as supplements. None is FDA-approved.

What is vilon?

A two-amino-acid peptide, Lys-Glu, from the Khavinson program. Khavinson is an author on about 63% of its PubMed records.

Is there good evidence for bioregulators?

Thin. Across about 650 PubMed records for eleven names, 20 are indexed as randomised trials, and only one of those concerns the short synthetic peptides other than thymogen.

Related on Grey Peptides

• Epithalon (epitalon)
• Thymalin
• Epitalon and telomeres

Sources

1. Grey Peptides dataset records for thymalin, cortexin, thymogen, epithalon, vilon, pinealon, cortagen, livagen, vesugen, chonluten and bronchogen (sequences and registration status); read October 2, 2026.
2. Araj, S. K., et al. (2025). Overview of Epitalon-Highly Bioactive Pineal Tetrapeptide with Promising Properties. Int J Mol Sci, 26(6). PMID: 40141333
3. Grey Peptides analysis of PubMed via NCBI E-utilities, October 2, 2026: title/abstract searches for eleven names, with and without Khavinson V* as author and restricted to randomized controlled trial[pt]; queries and counts in _ops/phase2/research/khavinson_pubmed_counts.json. Cardiogen excluded from pooled figures as a non-specific term.
4. Musienko, G. V. (1999). [Thymalin in the combined treatment of parkinsonism patients]. Lik Sprava, (1), 119-22. PMID: 10424021
5. Tsvelev, I. u. V., et al. (1992). [Thymogen in the complex treatment of inflammatory diseases of the female genital system]. Akush Ginekol (Mosk), (2), 54-7. PMID: 1476231
6. Smirnov, V. S., et al. (2011). [Application thymogen for preoperative preparation of elderly patients with tumor processes in abdominal cavity]. Adv Gerontol, 24(2), 278-84. PMID: 21957588
7. Kuznik, B. I., et al. (2022). [Morphological compound and indicators of the blood clotting system in severe COVID-19 patients of middle aged and elderly during treatment of Tocilizumab and Thymalin.]. Adv Gerontol, 35(3), 368-374. PMID: 36169363
8. Korkushko, O. V., et al. (2006). Geroprotective effect of epithalamine (pineal gland peptide preparation) in elderly subjects with accelerated aging. Bull Exp Biol Med, 142(3), 356-9. PMID: 17426848
9. Khavinson, V. K. h., et al. (2003). Epithalon peptide induces telomerase activity and telomere elongation in human somatic cells. Bull Exp Biol Med, 135(6), 590-2. PMID: 12937682

Educational information, not medical advice. Each dose in this guide names its source, an approved label or a published study. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose.