Reference · Study doses only
Thymulin Dosage in the Research Literature
There is no established human dose. What follows is study-context only — what was administered, to which species, by which route — reported as findings, never as guidance to follow.
Before the details
Thymulin dosage is a research topic here, not a how-to. There is no established human dose, and this page does not provide one. What exists is a scattered record of what researchers gave to animals and cells — usually tiny amounts, measured in nanograms or micrograms, given by injection routes that only make sense in a lab. Much of the recent work delivers thymulin through gene therapy (a vector that makes the body produce the peptide) rather than as a dose of the peptide itself. Read every number below as "administered at X in [species]," never as a protocol. Thymulin is a research peptide, not an FDA-approved drug or a supplement.
Thymulin Dosage in the Research Literature
Reported thymulin peptide dosage figures are study findings, not recommendations. In rodent anti-inflammatory and analgesia models, doses fell in the nanogram-to-low-microgram range per animal — on the order of 0.1–1 microgram intracerebroventricular, or roughly 1–1000 ng intraperitoneal [4]. In mouse systemic-inflammation models, research doses were given intraperitoneally, often daily or every other day; the LPS-pretreatment study dosed thymulin daily for two weeks before challenge [6]. A rat pulmonary-hypertension model used a subcutaneous regimen on the order of 100 ng/kg/day, per its source.
Gene-therapy studies do not report a peptide dose at all; they report a vector dose. A single intramuscular injection of the adenoviral analog RAd-metFTS used 10^7 PFU in mice and 10^8 PFU in rats to restore circulating thymulin [8]. The asthma study used a single intratracheal dose of thymulin-expressing plasmid in nanoparticles [7]. These are not peptide doses and do not translate into one.
How thymulin is administered in research
Across the literature, thymulin and the vectors expressing it were delivered by a range of routes, each chosen for the model. Reported routes include intraperitoneal and subcutaneous injection in systemic models [6], intracerebroventricular delivery in CNS and analgesia work [4], intratracheal delivery for inhaled gene therapy in the asthma model [7], and intramuscular injection for the adenoviral gene-therapy vector [8]. In-vitro studies applied thymulin directly to cells — for example, to rat pituitary cells for the ACTH-release assay [11] and to patient lymphocytes for the T-cell subset work [13]. A small pilot studied a topical zinc-thymulin formulation. Each route is a research method, not a consumer administration plan.
Thymulin Half-Life and Pharmacokinetics
Native thymulin has a short circulating half-life, as expected for a nine-residue peptide, but a precise human pharmacokinetic half-life is not well established in the public literature. This gap is part of why gene-therapy approaches were developed in the first place — to sustain circulating thymulin levels rather than to chase a short-lived peptide bolus [5][8].
A structural caveat shapes any pharmacokinetic reading: thymulin's activity requires its bound zinc ion. Zinc chelation abolishes activity, and the apopeptide is inactive until zinc is restored [1]. Any account of thymulin exposure is therefore inseparable from zinc availability, which complicates clean half-life and dose-response interpretation [2]. The in-vitro potency anchor that does exist is the pituitary ACTH result, maximal near 10 pM [11].
Is There a Thymulin Supplement?
There is no marketed thymulin supplement. Thymulin is a research peptide, not a dietary supplement, and it is not FDA-approved for any use. Because its activity depends on zinc, much of the human-facing research focuses on zinc status rather than on administering thymulin: in mildly zinc-deficient adults, serum thymulin activity was restored by zinc repletion [3]. That is a finding about zinc and an endogenous peptide, not an endorsement of any product.
Consumer writing sometimes lists thymulin supplement products that are in fact other thymic peptides — thymosin alpha-1, thymosin beta-4, or the bovine complex thymalin — which are chemically distinct from thymulin [9]. This site does not source, price, or recommend any product, and treats thymulin strictly as a subject of study.
Thymulin Side Effects: What the Literature Reports
Because thymulin has not been characterized in large modern human trials, there is no established human side-effect profile, and thymulin peptide side effects cannot be stated as clinical fact. The human record is limited to dated work — an open rheumatoid-arthritis trial of FTS-Zn [12] and in-vitro patient-lymphocyte studies [13] — plus historical studies that used the synthetic analog nonathymulin rather than native thymulin.
The literature's main cautions are interpretive rather than toxicological: thymulin is not FDA-approved and is handled as a research peptide; most evidence is preclinical; human data are sparse and dated; and because activity is strictly zinc-dependent, reported effects are entangled with zinc status [2]. No safety claim — favorable or unfavorable — can be drawn for human use from this record.
What doses of thymulin were used in animal studies?
Reported animal doses span nanogram-to-low-microgram amounts per animal — for example, roughly 0.1–1 microgram intracerebroventricular or 1–1000 ng intraperitoneal in rodent models [4] — with subcutaneous regimens in some models. Gene-therapy work instead reports vector doses, such as 10^7 PFU (mice) and 10^8 PFU (rats) of RAd-metFTS [8]. These are study-specific findings, not recommendations.
Is thymulin taken as an injection?
In studies, thymulin or vectors expressing it were given by injection routes including intraperitoneal, subcutaneous, intramuscular, and intracerebroventricular [4][6][8], and by intratracheal delivery for inhaled gene therapy [7]. This describes research administration in animal and cell models, not a consumer protocol — and the gene-therapy injections deliver a vector, not a peptide dose.