Search ↗

Classes

Thymic & immune

Thymus-derived peptides that modulate T-cell function and immune signalling.

3 compounds in this class. 0 approved by the FDA for at least one indication. 0 have no published human trial data.

Guides in this class

All 3 thymic & immune compared

CompoundEvidenceReported rangeHalf-lifeStatus
Thymalin
A polypeptide fraction extracted from calf thymus, used clinically in Russia and studied in long-term geriatric cohorts.
 Preliminary human 10-20 mg Not established Research only
Thymosin Alpha-1
A thymic immunomodulatory peptide approved in more than 30 countries for hepatitis B and C, though not in the United States.
 Clinical trials 1.6-3.2 mg ~2 hours Research only
Zn-Thymulin
A zinc-dependent thymic nonapeptide, of interest for immune signalling and marketed as a topical hair-loss product, though a hair benefit is not established in humans.
 Preliminary human 100-200 mcg ~30 minutes Research only

Head-to-head comparisons

Thymalin vs Thymosin Alpha-1Thymalin vs ThymogenThymalin vs Zn-ThymulinThymogen vs Thymosin Alpha-1Thymosin Alpha-1 vs Zn-ThymulinLL-37 vs Thymosin Alpha-1GHK-Cu vs Zn-Thymulin

Thymic & immune: common questions

What are thymic & immune?

Thymus-derived peptides that modulate T-cell function and immune signalling. This class has 3 compounds in our directory.

Which thymic & immune are FDA approved?

None of the 3 compounds in this class is FDA approved for any indication.

Which thymic & immune have the strongest evidence?

By evidence level and number of human studies: Thymosin Alpha-1 (clinical trials, ~40 human studies); Thymalin (preliminary human, ~5 human studies); Zn-Thymulin (preliminary human, ~2 human studies).

Can compounding pharmacies make these?

Thymalin, Thymosin Alpha-1, Zn-Thymulin are not FDA approved and not on the 503A bulks list, so there is no routine legal path to compound them. Material sold online is labelled for research use only. Status checked against FDA lists in October 2026.

References

Regulatory and primary sources

  1. FDA: Bulk drug substances that may present significant safety risks (Category 2 and withdrawn nominations) ↗ · content current as of April 22, 2026; checked October 18, 2026
  2. FDA: Bulk drug substances used in compounding under section 503A ↗ · how the 503A categories work
  3. FDA: Unapproved drugs ↗ · status of products sold "for research use only"
  4. WADA Prohibited List ↗ · peptide hormones and growth factors, class S2
  5. PubMed (National Library of Medicine) ↗ · source of every literature reference on this site

Published literature

  1. Khavinson VKh. Peptides and Ageing.Neuro Endocrinol Lett 2002.PubMed 12374906
  2. Khavinson VKh, Morozov VG. [Geroprotective effect of thymalin and epithalamin].Adv Gerontol 2002.PubMed 12577695
  3. Litvinenko GI, Shurlygina AV, Dergacheva TI, et al.. Chrono- and Immunocorrection of Inflammatory Disorders of Internal Reproductive Organs in Women of Reproductive Age.Bull Exp Biol Med 2015.PubMed 26033592 · doi:10.1007/s10517-015-2890-0
  4. Khavinson VKh, Morozov VG. Peptides of pineal gland and thymus prolong human life.Neuro Endocrinol Lett 2003.PubMed 14523363
  5. Lin'kova NS, Poliakova VO, Kvetnoĭ IM, et al.. [Characteristics of the pineal gland and thymus relationship in aging].Adv Gerontol 2011.PubMed 21809618
  6. Lin'kova NS, Poliakova VO, Trofimov AV, et al.. [Influence of peptides from pineal gland on thymus function at aging].Adv Gerontol 2010.PubMed 21510076
  7. Musienko GV. [Thymalin in the combined treatment of parkinsonism patients].Lik Sprava 1999.PubMed 10424021
  8. Domina EA. Chornobyl catastrophe: cytogenetic effects of low dose ionizing radiation and their modification.Exp Oncol 2016.PubMed 28230819
  9. Hannappel E. beta-Thymosins.Ann N Y Acad Sci 2007.PubMed 17468232 · doi:10.1196/annals.1415.018
  10. Ancell CD, Phipps J, Young L. Thymosin alpha-1.Am J Health Syst Pharm 2001.PubMed 11381492 · doi:10.1093/ajhp/58.10.886
  11. Hadden JW. T-cell adjuvants.Int J Immunopharmacol 1994.PubMed 7806429 · doi:10.1016/0192-0561(94)90090-6
  12. Hadden JW. Thymic endocrinology.Ann N Y Acad Sci 1998.PubMed 9629262 · doi:10.1111/j.1749-6632.1998.tb09574.x
  13. Rubin BK. Unmet needs in cystic fibrosis.Expert Opin Biol Ther 2018.PubMed 30063865 · doi:10.1080/14712598.2018.1484101
  14. Hoch K, Volk DE. Structures of Thymosin Proteins.Vitam Horm 2016.PubMed 27450728 · doi:10.1016/bs.vh.2016.04.009

Literature retrieved from PubMed on October 16, 2026, favouring human studies and reviews. Numbered markers in the text show which paper supports which statement; uncited entries are background reading.