Thymulin

Areas of active research — not promised effects

Each tag links to other compounds with research into that goal. Research use only: these are areas of study, not human-use claims.

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Thymulin is not FDA-approved for any human therapeutic indication and is not listed on the FDA 503A or 503B bulk drug substances lists. It has no established lawful compounding pathway under federal law. Sale and possession for human use is not authorised; it may be sold and held only for legitimate in vitro or animal research purposes.

Transparent blend · bci-1.0 · never paid-placement

Primary name

Thymulin

Origin

Naturally produced and secreted by thymic epithelial cells; first isolated from serum and originally designated Facteur Thymique Serique (FTS, serum thymic factor) by Bach et al. in 1977. Requires equimolar zinc for biological activity.

Registry IDs

PubChem CID

71300623

CAS

78922-62-0

InChIKey

LIFNDDBLJFPEAN-YTAPOSPOSA-N

Molecular formula

C33H54N12O15

Molar mass

858.9 g/mol

Monoisotopic

858.38315906 Da

InChIKey

LIFNDDBLJFPEAN-YTAPOSPOSA-N

Appearance

White to off-white lyophilised powder

Solubility

Soluble in water and dilute aqueous buffers; solubility enhanced in the presence…

Sequence not available in current seed.

Stability: Short circulating half-life (~10 min, indicative) due to serum peptidase activity. Zinc-free form is biologically inactive; loss of zinc cofactor under chelatin

Vial sizes

2 mg · 5 mg

Purity grades

≥98% (HPLC)

Salt forms

Free base (primary)

• GHS hazard class on file
• PPE & spill response
• Disposal guidance
• Not-for-human-consumption posture

How much research exists, and of what maturity — never a verdict on whether it works.

Mechanism of action

• Thymulin binds zinc in a 1:1 ratio; the resulting metallopeptide complex adopts the three-dimensional conformation recognised by receptors on immature thymocytes and peripheral T-cell subsets
• Receptor engagement promotes expression of T-cell surface markers (CD2, CD3, CD4, CD8) and drives differentiation of immature thymocytes into functionally competent cytotoxic and helper T cells
• Separately, thymulin suppresses pro-inflammatory cytokine production (TNF-α, IL-1β, IL-6) via inhibition of NF-κB nuclear translocation and p38 MAPK signalling in peripheral immune and epithelial cells, contributing to analgesic and anti-inflammatory effects observed in rodent models

Pharmacokinetics (ADME)

Half-life

Approximately 10 minutes (exogenous peptide, serum; rapid degradation by serum peptidases reported in vendor-cited literature — no peer-reviewed PK study identified in gathered PMIDs)

PK–PD note: No formal peer-reviewed PK/PD study was identified among the gathered PMIDs. The ~10-minute half-life figure circulates widely in vendor literature and is consistent with the known susceptibility of s…

Reading the evidence

• Evidence quality and gaps vary by application — see the cited grades above.
• Indexed-article counts span all evidence tiers, not only completed human trials.
• No first-party human-dosing, efficacy, or benefit claims are made here.

Key reviews & evidence-gap sources

• Wolf E, Milazzo S, Boehm K, Zwahlen M, Horneber M. Thymic peptides for treatment of cancer patients. Cochrane Database Syst Rev. 2011;(2):CD003993. — Cochrane systematic review of thymic peptides (thymostimulin, thymosin fraction 5, thymopentin, thymosin α1) in cancer; does not isolate thymulin specifically. Found no OS/DFS/TR benefit for purified thymus extracts; trend for thymosin α1.
• Reggiani PC, et al. The thymus-neuroendocrine axis: physiology, molecular biology, and therapeutic potential of the thymic peptide thymulin. Ann N Y Acad Sci. 2009;1153:98-106. — Thymulin-specific narrative review covering neuroendocrine axis and therapeutic potential.
• Review of Thymic Peptides and Hormones: From Their Properties to Clinical Application. Int J Pept Res Ther. 2024. — Comprehensive review of thymic peptides including thymulin structure, properties, mechanism, and clinical applications.
• Dardenne M, et al. Thymulin, a zinc-dependent hormone. Med Oncol. 1989. — Foundational review establishing thymulin as a zinc-dependent metallopeptide inducing T-cell differentiation.

No registered human trials found for this compound.

Status

No registered trials found

Summary (literature)

No controlled human safety studies were identified in the gathered literature. Thymulin is an endogenous peptide, but exogenous administration could theoretically perturb T-cell subset balance or cytokine homeostasis in individuals with pre-existing immune dysregulation, autoimmu…

WADA status

Not specifically listed on the 2026 WADA Prohibited List. Thymulin does not appear by name in the 2026 List of Prohibited Substances and Methods. However, WADA'…

Dominant research route: SC

Research protocols (immune modulation); cited as typical research-administration route for the peptide

Bioavailability: Direct systemic absorption intended; thymulin has a very short serum half-life (on the order of minutes) and is rapidly inactivated in serum, motivating nanoparticle/gene-therapy delivery strategies

Peptide reference databases state thymulin is typically administered via subcutaneous or intraperitoneal injection in research settings; no located human PK trial of direct SC thymulin peptide

Animal research settings (rodent immune/diabetes models)

Bioavailability: Used as a parenteral research route alongside SC; no human PK data located

Listed as a standard research-administration route for thymulin in animal studies; no specific bioavailability values sourced

Animal models (CNS/neuroprotection; nanoparticle thymulin gene therapy for allergic asthma in mice)

Bioavailability: Intranasal zinc-thymulin complex reported to bypass the blood-brain barrier and achieve CNS exposure; nanoparticle-based thymulin gene therapy (not free peptide) delivered intranasally reversed asthma pathology in mice

Intranasal route studied primarily for CNS-targeting and via gene-therapy/nanoparticle formulations rather than free peptide; no human intranasal thymulin PK data located

Animal & human figures are kept visibly separate so studied animal doses are never misread as human guidance.

Sorted A–Z by vendor — never by price

Weekly median $/mg from the live vendor crawl.

Researched storefront prices, bucketed

p25 $4.56 · median $5.52 · p75 $6.50 · 7 researched vendors

Legit, COA-backed band: $3.50–$7.50/mg.

Value rule: don't just buy the cheapest — a price under $3/mg is a red flag. Pair price with COA and independent-test grade.

Estimated cost of research (10 mg)

Vial (best researched price)

$38

Bacteriostatic water (generic estimate)

$6

Syringes / supplies (generic estimate)

$12

What each test proves — general guidance, plus this compound's researched purity data

Purity on the current market (researched)

~98–99% (vendor-reported; Janoshik HPLC/LCMS analysis offered for Thymalin/Thymulin; aggregate vendor COAs cite ≥98–99%)

Independent labs cited for this compound

No FDA recalls, market withdrawals, or safety alerts naming Thymulin/Thymalin were found in the FDA enforcement databases reviewed. The only compound-specific regulatory action identified is the 2024 warning letter to US Chem Labs.

Buyer red-flag checklist

• Thymulin/Thymalin is not FDA-approved as a drug; products sold with disease-treatment claims (immune, endocrine, cardiovascular) are classified as unapproved new drugs (FDA Warning Letter 669074, 2024).
• 'Research use only' / 'not for human consumption' labeling has been explicitly rejected by FDA as a shield when human-use claims are present on the same website.
• Thymulin is frequently conflated with Thymalin and Thymosin alpha-1 in the grey market; identity mislabeling risk is elevated for low-volume thymic peptides.
• No compound-specific FDA import alert was found, but peptide bulk powders of Chinese origin are commonly detained under general unapproved-new-drug and misbranding authorities.
• Public third-party purity data for Thymulin is sparse compared to GLP-1 agonists; vendor self-reported '99% purity' claims are not independently corroborated at scale.

GMP vs research-grade: the chemistry (SPPS + HPLC + MS) is identical — the difference is the quality system.

Underdosing / mislabeling: No independent third-party lab test results (Janoshik/MZ Biolabs/Finnrick) specific to Thymulin/Thymalin underdosing were located in the public databases reviewed. Thymulin is a low-volume peptide relative to GLP-1 agonists and is not among the most-tested compounds in the Janoshik public-tests mirror (which is dominated by retatrutide, tirzepatide, GHK-Cu).

• An RUO label is not an import exemption — CBP judges actual intended use.
• Lyophilized powder is ambient-stable in transit; temperature control needed for > 7-day transit.
• US-warehouse vendors dodge import scrutiny — they cost more but ship more reliably.

Every item dated & sourced

Not specifically named on the WADA Prohibited List; thymulin is not listed as a prohibited substance. (Note: WADA Prohibited List page could not be directly retrieved due to JavaScript; status based on secondary aggregator reporting and absence from list search.)

No granted patents identified in current seed. Composition-of-matter coverage is limited given the peptide's synthetic origin.

• IACUC / IRB research context
• RUO buyer responsibilities & documentation
• Veterinary / alternative-use where lawful
• Jurisdiction-aware "who may lawfully obtain"

What people discuss

Reported concerns — discussion, not established effects

Reading caveats

• small sample size; Thymulin is a low-volume niche peptide relative to BPC-157/TA-1
• Thymalin/TA-1 conflation contaminates the Thymulin-specific signal across multiple threads
• vendor-affiliated clinic content present in aggregator results (e.g., med-spa/longevity clinics selling therapy)

Manually researched from reddit, youtube— theme weights are research estimates, not live counts; aggregated & de-identified. No individual posts, quotes, or usernames are ever shown.

Relative research / market volume — populated once the activity stream is wired

Inline tooltips for lyophilized, RUO, EU/mg, SPPS, 503A and more.

Toggle plain-language ↔ scientific in the header.

• How to read a COA
• Free base vs acetate
• Understanding evidence grades

Zinc-dependent nonapeptide thymic hormone that promotes T-cell maturation and modulates immune balance; studied in aging and inflammatory disease models. Approximately 373 articles are indexed (literature last scanned 2026-05-29). US regulatory status: Research Use Only; not FDA-approved. Research use only.

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