Not FDA approved and sold as a research chemical. This page is educational information only. It is not medical advice and not a recommendation to use anything.

IndexedBuilt automatically from public databases on 2026-09-30. Not yet hand-reviewed by PLOBT.How this works →

Thymulin

Not FDA approved

Thymic nonapeptide hormone

Also known as: serum thymic factor, FTS, THYMIC FACTOR, CIRCULATING, Facteur thymique serique, Thymuline, Circulating Thymic Factor, Thymic Circulating Factor, Serique, Facteur Thymique, Thymique Serique, Facteur

Evidence score

21/ 100

Thin evidence

Very thin human evidence

Regulatory standing. Sold as a research chemical, not approved
Animal / preclinical only. Evidence is largely animal or in-vitro
No registered human trials. Nothing registered on ClinicalTrials.gov
1 cited source. Includes primary / regulatory sources

Computed with the same four public criteria as every profile. The human-evidence grade on an indexed profile is set automatically and may change when it is hand-reviewed. It is not a safety score, not a purity rating, and not medical advice, and not a claim that this compound treats, cures, or prevents any condition.

What it is

Thymulin, also called serum thymic factor (FTS), is a nine amino acid peptide produced by epithelial cells of the thymus. It requires zinc to be biologically active and is thought to help regulate T cell maturation and immune signaling, with some research also exploring effects on inflammation and the nervous system.

What the evidence shows

Automatic summaryAnimal / preclinical

Most of the roughly 400 published papers are laboratory and animal studies, with only small, older human investigations and no registered human clinical trials. It is not FDA-approved, and no benefit in humans has been established.