Thymulin
Price and cost-per-mg comparison
Thymulin (facteur thymique serique; FTS; synthetic form nonathymulin) is an endogenous zinc-dependent nonapeptide (Glu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn, with an N-terminal pyroglutamate) produced exclusively by thymic epithelial cells, identified by Dardenne and Bach in the 1970s as the circulating thymic hormone responsible for promoting T-cell differentiation and maturation in the peripheral immune system. Its defining property is zinc dependence: in the 1982 study that named it, the zinc-free peptide was biologically inactive in a rosette assay, activity was restored by zinc salts with a 1:1 zinc-to-peptide ratio giving the best activation, and the name thymulin (FTS-Zn) was proposed for the active zinc-bound form. The zinc-thymulin complex binds to receptors on immature T-lymphocytes promoting their differentiation and modulates the neuroendocrine-immune axis through interactions with pituitary hormones; in mice, a marginally zinc-deficient diet lowered circulating thymulin within two months without thymic atrophy, and the loss was reversible by adding zinc in vitro. Thymulin is not the same substance as thymalin, the Russian thymus-extract preparation, despite the similar names. Circulating thymulin follows a defined age curve: in a series of 93 healthy people from birth to 80 years, it was already detectable at birth, rose to its highest level in children aged 5–10 years, fell from adolescence to its lowest value at 36 years and then stayed steady into old age. Its serum concentration also follows a 24-hour rhythm, rising at night in rats and in humans, with melatonin implicated in the nocturnal increase. Human trial evidence is sparse and old. Two small randomized, double-blind, placebo-controlled trials in rheumatoid arthritis (Ann Rheum Dis, 1987) compared three nonathymulin dose schedules (1, 5 and 10 mg/day); 5 mg/day proved the most efficient, with significant clinical improvement on global assessment (56% versus 17% on placebo) and on four objective parameters, and minimal adverse effects. A randomized, double-blind, placebo-controlled pilot in 40 patients with multiple sclerosis (Acta Neurol Scand, 1989) found no effect on disability scores. Those are the only thymulin-as-treatment trials indexed on PubMed as of August 2026, and none concerns age-related immune decline; the immune-senescence case rests on reviews from the Dardenne (Institut Pasteur) and Goya groups and on animal work, including a rat collagen-induced arthritis model in which thymulin reduced joint swelling and anti-collagen antibody. Thymulin has no FDA approval and no approved therapeutic indication in any major jurisdiction; it is a research compound with biological plausibility for immune-senescence applications, though the thin, dated human evidence and the zinc-dependency of its active form are important limitations for any discussion of exogenous supplementation.
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Filter by vial size and quantity — the figures and table follow.
| Vendor | Size | Price | Cost per mg▲ | COA | Source | Availability | Actions |
|---|---|---|---|---|---|---|---|
10 mgsingle vials3 listingsmedian $4.00 / mg | |||||||
US Thymulin (10mg) | 10 mg vial | $39.99 | $4.00Lowest | — | Vendor feed · 2 d ago | In stock | View ↗ |
US Finnrick A Thymulin 10mg | 10 mg vial | $40.00 | $4.00 | Vendor feed · 2 d ago | In stock | View ↗ | |
US Thymulin | 10 mg vial | $65.00 | $6.50 | — | Vendor feed · 2 d ago | In stock | View ↗ |
Other sizessingle vials, one listing each2 listingsmedian $5.50 / mg | |||||||
US Thymulin 20mg | 20 mg vial | $40.00 | $2.00 | Vendor feed · 2 d ago | In stock | View ↗ | |
US Thymulin | 5 mg vial | $45.00 | $9.00 | — | Vendor feed · 2 d ago | Out of stock | View ↗ |
Not comparableno resolvable mg — shown, not ranked3 listings | |||||||
US Thymulin | mass not stated | $84.00 | — | Vendor feed · 2 d ago | In stock | View ↗ | |
US Thymulin | mass not stated | $84.00 | — | Vendor feed · 2 d ago | In stock | View ↗ | |
CA Thymulin — 20mg | FTS Zinc-Binding Nonapeptide | mg not resolved | $72.00 | — | Vendor feed · 2 d ago | In stock | View ↗ | |
— in COA: no certificate on file for this vendor— in availability: stock not read at the last checkPrices as scraped; foreign prices converted to USD
When Thymulin prices moved
2 days in the last 120 on which a feed run read comparable Thymulin prices from 3 or more vendors. Each point is the median $/mg across every comparable listing read that day, sized by how many vendors were read. A log of run days, not a continuous series.
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| Date | Median $/mg | Vendors read |
|---|---|---|
| 28 Sept 2026 | $4.00 | 4 |
| 19 Sept 2026 | $4.00 | 3 |
How these prices are computed
The short version. The methodology page has the rest.
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$/mg
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