Zinc Thymulin (10mg Vial) Dosage Protocol

Quickstart Highlights

Thymulin is a nine-amino-acid hormone made by thymic epithelial cells, sequence Pyr-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn, formerly called FTS (facteur thymique sérique). Its defining property is that it does not work without zinc: Dardenne and colleagues showed in PNAS that antibodies raised against the hormone recognise only the zinc-coupled molecule, and that the zinc-containing form has a unique structure^[1]. Bach and Dardenne put it plainly four years later — the peptide’s “biological activity and antigenicity depend upon the presence of the metal zinc in the molecule”^[2]. “Zinc thymulin” is therefore not a different peptide from thymulin. It is thymulin in the state in which thymulin actually works.

What brings people to this page is not immunology, though — it is hair. That interest traces to a single 2012 research Letter in the Journal of Investigative Dermatology, in which human scalp hair follicles in organ culture grew faster when 10 pg/mL of thymulin was added to the medium^[3]. Everything else written about zinc thymulin and hair descends from that Letter and from one uncontrolled case series published five years later in a journal that PubMed does not index^[6]. This page separates the two, and is explicit about what neither of them can tell you. Our Thymulin 5 mg protocol covers the injectable immune side of the same molecule.

Dosing & Application

This is the part of the page that most sources get wrong, and the reason is simple: there is no number to report. Zinc thymulin has one measured concentration in the literature, it comes from a dish, and it is roughly nine orders of magnitude below anything a person could weigh out. What follows explains the figure, explains why it cannot be carried across to a scalp, and gives the dilution arithmetic for a 10 mg vial so that anyone reading a product label can at least check whether the label is plausible.

Standard / Gradual Approach

The figure, and where it comes from. Meier and colleagues cultured human scalp hair follicles from three donors for seven days with 10 pg/mL of thymulin. Treated follicles showed an increased hair shaft growth rate against vehicle controls, stayed in anagen longer, and contained significantly more melanin granules^[3]. That is the entire peer-reviewed hair dataset for this peptide, and it was published as a Letter — the short format, not a full paper.

Why 10 pg/mL is not a recipe. In organ culture the follicle sits in the medium, so the concentration at the tissue is the concentration in the dish. On an intact scalp, a peptide has to survive the vehicle, cross or bypass the stratum corneum, and reach a follicle several millimetres down; what fraction arrives is unknown and unmeasured for this molecule. A topical formulation therefore has to be higher than the ex-vivo figure by some factor nobody has established — which is precisely why no concentration has ever been published, and why anyone quoting one is quoting themselves.

The scale of the gap, in plain arithmetic. Ten picograms per millilitre is 0.00000001 mg/mL. A 10 mg vial divided by that concentration gives 10⁹ mL — one million litres. Dissolve the same vial in a 30 mL dropper bottle instead and you get 333 µg/mL, which is about 33 million times the organ-culture concentration. Neither number is a recommendation. They are the two ends of a range that the literature simply does not cover.

What the human report says about application, and what it does not. The 2017 case series describes zinc thymulin synthesised by standard Fmoc chemistry and given as a water-based topical spray to the scalp, in 18 subjects aged 35 to 90 with Norwood 2–7 pattern loss, over individual trial durations of four to ten months and 3,300 treatment days in total, with no adverse or local side effects reported^[6]. It is an uncontrolled series in a journal PubMed does not index, and its full text could not be retrieved on 24 August 2026 — so no efficacy figure from it is quoted anywhere on this page, and no concentration either.

Supplies Needed

Verified on 24 August 2026: zinc thymulin is genuinely sold as a 10 mg lyophilizate. Two storefronts list it at €60 with the same specification — purity >97%, excipients zinc and mannitol, amino-acid sequence Pyr-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn-OH, molecular weight 858.85, formula C₃₃H₅₄N₁₂O₁₅, storage at or below +5 °C^[4][5] — and both name the same manufacturer, so that is two storefronts and one source, not two independent makers. What you need beyond the vial is a sterile diluent, an accurate small-volume pipette, an amber dropper bottle, and a certificate of analysis for the batch. There is nothing here to inject and no reconstitution calculator on this page.

Zinc Thymulin Vial

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Protocol Overview

The most common error made about this compound is treating “zinc thymulin” as a distinct, characterised molecule. Read the vendor sheets and the picture is different: the molecular weight they quote, 858.85, and the formula C₃₃H₅₄N₁₂O₁₅, belong to the free nonapeptide, and zinc appears in the excipient list next to mannitol^[4][5]. What is in the vial is thymulin powder formulated with zinc, not an isolated and characterised zinc-peptide complex.

That is not a scandal — it may well be the practical way to supply an active preparation, since the zinc-bound conformation forms in solution. But it does mean the product name promises more precision than the label delivers, and it means the ratio of zinc to peptide, which is the one thing that would make “zinc thymulin” a specification rather than a description, is not stated on either sheet.

It also matters biologically, because the zinc dependence is real and well documented. Dardenne’s PNAS work showed that monoclonal antibodies able to block the hormone’s activity recognise only the zinc-coupled molecule, consistent with NMR evidence that the zinc-containing form has a unique structure^[1]. Zinc-deficient people have measurably reduced serum thymulin activity^[8]. Without zinc, the peptide is present but inactive — which is exactly why the preparation exists at all.

Dosing Protocol

Reference arithmetic only — none of these rows is a recommendation, because no topical concentration for zinc thymulin has ever been published. Each row takes a concentration, gives the volume that one 10 mg vial would make at that strength, and states what a 30 mL dropper bottle would need. The first row is the only concentration with a measured effect behind it, and it is an organ-culture figure.

Storage Instructions

Both vendor sheets specify storage at or below +5 °C for the lyophilised powder^[4][5], which is stricter than the room-temperature shipping many peptide vendors quote. Follow the batch certificate rather than a generic rule, and treat a vial that has spent time warm as an unknown.

The powder is hygroscopic and the vial is the packaging. Mannitol is there as a bulking agent for the freeze-drying process; it also draws moisture. Keep the stopper intact, let a cold vial come to room temperature before opening so condensation forms outside rather than inside, and do not decant powder between containers.

A solution has a much shorter life than the powder, and no published stability data exist for this one. An aqueous peptide solution without a preservative is a growth medium, and a nonapeptide with serine and asparagine residues has deamidation and hydrolysis routes available to it. Anything made up needs a preservative system, refrigeration, an amber bottle and a date — and there is no study to tell you what that date should be.

Important Notes

These are the points that go missing every time this peptide is written up as a hair-growth breakthrough.

• ▪The peer-reviewed hair result is ex vivo, and it is a Letter. Meier et al. cultured follicles from three human donors for seven days^[3]. That is a real, published, independent result from a serious group in a serious journal — and it is also three scalps and a week in a dish. It establishes that thymulin does something to a follicle in culture. It establishes nothing about a head.
• ▪The only human report is uncontrolled and is not indexed in PubMed. Eighteen subjects, no control group, no randomisation, no blinding, individual durations ranging from four to ten months^[6]. A search of PubMed on 24 August 2026 does not return it. Without a control arm, a hair study cannot distinguish a treatment effect from seasonal shedding, regression to the mean, or the well-documented tendency of people who start a hair treatment to also start photographing their hair more carefully.
• ▪The publisher matters here, and it is a matter of public record. That report appeared in an OMICS Group / Longdom title. In April 2019 a US federal court entered a judgment of $50.1 million against OMICS Group and its founder on Federal Trade Commission charges of deceptive practices — including deceptively claiming rigorous peer review, and falsely claiming that its journals were listed in reputable databases such as PubMed^[7]. That does not prove any individual article is wrong. It does mean the usual quality signal a journal name carries is absent, and that the paper has to stand on its own design — which, being uncontrolled and n=18, it cannot.
• ▪No efficacy number from that report is repeated on this page, on purpose. Its full text could not be retrieved on 24 August 2026: the publisher’s PDF endpoints returned server errors on every mirror tried, and the repository copy refused access. Details given here — design, subject numbers, demographics, duration, route, absence of reported adverse effects — are those confirmable from the indexed abstract. Anything else would be repeating a figure we have not read.
• ▪“Zinc thymulin” and “thymulin” are the same peptide in different states. The zinc is what makes the molecule active^[1][2], so a product sold as plain thymulin is not a weaker version of a different compound — it is the same nonapeptide, and whether it is in the active conformation depends on zinc being available. Our Thymulin 5 mg page covers the injectable immune literature on the same molecule.
• ▪The immune framing on the vendor pages is not the hair evidence. Both listings sell the vial as an immunostimulant and describe effects on T-cell maturation, macrophage activation and the nervous system^[4][5]. Whatever the merits of that literature — and it is a real body of work going back to the 1980s — it comes from systemic administration in immunology models, not from anything applied to a scalp.
• ▪Thymic peptides are not interchangeable. The same 2012 study that found thymulin promoted follicle growth reported that thymic peptides differentially modulate hair follicle growth^[3] — the word is in the title. Results for thymosin beta-4, thymalin or thymosin alpha-1 do not transfer to thymulin, and vice versa.

How This Works

The mechanism proposed for hair is anagen prolongation rather than follicle creation. In the 2012 organ-culture experiments, thymulin-treated follicles grew faster over seven days, remained in anagen longer than vehicle-treated controls, and contained significantly more melanin granules^[3]. A follicle that stays in growth phase longer produces a longer, thicker shaft before it sheds — the same endpoint minoxidil is understood to act on, by a different route.

Why a thymic hormone would touch a hair follicle at all is less strange than it sounds. The hair follicle is an immune-privileged mini-organ, and its cycling is under substantial immune and neuroendocrine control — which is the framework the Paus group, senior authors on that Letter, have spent decades building. There is also an older clinical thread linking thymic function to hair: a 1995 study examined the role of the thymus gland in alopecia areata^[9]. None of that constitutes proof for topical zinc thymulin; it explains why the hypothesis was worth testing.

The zinc is not incidental to any of this. Thymulin’s activity requires the metal to be bound^[1][2], and the association runs the other way too: reduced serum thymulin activity is one of the documented markers of mild human zinc deficiency^[8]. In a topical preparation, zinc is doing chemistry, not marketing — without it the peptide in the vial is in the wrong conformation to do anything.

Lifestyle Factors

Judge it over a hair cycle, and against something. The uncontrolled report ran four to ten months per subject^[6], and that timescale is right — but the lesson of an uncontrolled study is that a timescale without a comparison arm tells you very little. If you are going to try it, photograph a fixed area under fixed lighting at fixed intervals and change nothing else, because that is the only control available outside a trial.

Do not stop something that works in order to try something that has not been shown to. Minoxidil and finasteride have randomised, controlled, placebo-compared evidence in androgenetic alopecia. Zinc thymulin has three donors in a dish and eighteen people without a control group. Those are not the same category of claim, and nothing on this page should be read as a reason to swap one for the other.

Keep the regulatory position straight. Zinc thymulin is not approved for any human use anywhere, is sold explicitly for research purposes only^[4][5], and has no established topical concentration. It is an experimental compound with an interesting preclinical signal and an evidence file too thin to support a recommendation of any kind.

Potential Benefits & Side Effects

What follows separates what has been measured from what is claimed. For this compound the gap between the two is unusually wide, and almost every claim in circulation rests on a single seven-day experiment on three donated scalps.

How to Apply

There is no protocol to give here, because none has been published. What follows is the sequence a careful person would work through: confirm what is in the vial, understand that any concentration chosen is unvalidated, and set up the observation so the result means something. Educational reference — not a formulation service, and not medical advice.

Skin Preparation

• ▪Confirm what the label actually says. The specification on both storefronts checked is: sequence Pyr-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn-OH, MW 858.85, formula C₃₃H₅₄N₁₂O₁₅, purity >97%, excipients zinc and mannitol^[4][5]. Note what that means: the molecular weight is the free peptide, so the zinc-to-peptide ratio is not specified. Ask for the batch certificate.
• ▪Understand that you are choosing a concentration nobody has validated. The table above is arithmetic. The only measured figure, 10 pg/mL^[3], is an organ-culture concentration and is not transferable. Anyone who tells you the “correct” topical strength is telling you their own guess.
• ▪Decide the vehicle before the concentration. An aqueous solution needs a preservative system or it becomes contaminated within days; an alcohol lotion is more stable and more irritating. The one human report used a water-based spray^[6], which is the only vehicle with any human exposure behind it at all.

Applying the Product

• ▪Work out whether the mass is weighable. A 30 mL bottle at 100 µg/mL needs 3 mg — below the resolution of an ordinary balance. The practical route is to dissolve the whole 10 mg vial in a measured volume and dilute from that, rather than trying to weigh a fraction of a vial.
• ▪Keep everything cold and clean. The powder is specified at or below +5 °C^[4][5]. Use a sterile diluent, work quickly, and refrigerate the made-up solution in an amber bottle with a date on it.
• ▪If the human report is your reference, match its route. That means a water-based spray applied to the scalp^[6] — not a serum, not micro-needled in, and not injected. A different route is a different experiment, and the (thin) human safety observation stops applying to it.
• ▪Do not treat the picogram figure as an instruction to go higher without limit. The gap between the organ-culture concentration and anything sprayable is real, but it is unquantified in both directions. “More must be better” is not what the study showed; it is what people assume when a study gives them a number they cannot use.

After Application

• ▪Give it four to ten months if you want to mirror the only human exposure on record^[6], and photograph a fixed area under fixed lighting throughout. Anything shorter measures shedding variation.
• ▪Change one variable at a time. If the routine also includes minoxidil, micro-needling, ketoconazole or a multi-active serum, the result will tell you nothing about zinc thymulin — which is exactly the flaw that makes the existing literature so hard to interpret.
• ▪Hold the conclusion loosely. The complete evidence file is one seven-day organ-culture Letter from three donors and one uncontrolled series of eighteen people in a journal PubMed does not index. That is a reason to find the compound interesting. It is not a reason to believe it works.

Recommended Source

For high-purity research peptides, we point researchers to Prime Lab Peptides for Zinc Thymulin (10 mg).

References

1. 1
   Proceedings of the National Academy of Sciences (1985) — A zinc-dependent epitope on the molecule of thymulin, a thymic hormone

   Dardenne M, Savino W, Berrih S, Bach JF. Proc Natl Acad Sci U S A 1985;82(20):7035–8 (PMID 2413455, PMC391304, DOI 10.1073/pnas.82.20.7035). Establishes the central fact about this molecule: thymulin is a nonapeptide from thymic epithelial cells whose “biological activity is strictly dependent on the presence of the metal zinc in the molecule”. Monoclonal antibodies able to inhibit that activity recognised exclusively the zinc-coupled form, consistent with NMR evidence that the zinc-containing hormone has a unique structure. Retrieved from PubMed, 24 August 2026.

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2. 2
   Medical Oncology and Tumor Pharmacotherapy (1989) — Thymulin, a zinc-dependent hormone

   Bach JF, Dardenne M. Med Oncol Tumor Pharmacother 1989;6(1):25–9 (PMID 2657247, DOI 10.1007/BF02985220). Review by the group that characterised the hormone, restating that its “biological activity and antigenicity depend upon the presence of the metal zinc in the molecule”, that it induces T-cell differentiation and enhances T-cell subset function, and that it is available in synthetic form. The source for the immunological framing that the vendor listings repeat — and note that all of it concerns systemic, not topical, administration. Retrieved from PubMed, 24 August 2026.

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3. 3
   Journal of Investigative Dermatology (2012) — Thymic peptides differentially modulate human hair follicle growth

   Meier N, Langan D, Hilbig H, Bodó E, Farjo NP, Farjo B, Armbruster FP, Paus R. J Invest Dermatol 2012;132(5):1516–9 (PMID 22402437, DOI 10.1038/jid.2012.2). The entire peer-reviewed basis for the hair interest in this peptide, and the source of the 10 pg/mL figure used throughout this page. Human scalp hair follicles from three donors were maintained in organ culture for seven days; follicles treated with 10 pg/mL thymulin showed an increased hair shaft growth rate compared with vehicle-treated controls, remained in anagen longer, and contained significantly more melanin granules. Published as a Letter. The title’s word “differentially” is doing real work: results for one thymic peptide do not transfer to another. Retrieved from PubMed, 24 August 2026.

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4. 4
   Peptide-Products.com — ZINC THYMULIN (10 mg) product listing (manufacturer: Russian Peptide)

   Vendor record verifying that the 10 mg size is genuinely sold. Lyophilizate, €60, purity over 97%, excipients zinc and mannitol, amino-acid sequence Pyr-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn-OH, molecular weight 858.85, formula C33H54N12O15, storage no warmer than +5 °C, sold for research and scientific purposes only. Note that the quoted molecular weight is that of the free nonapeptide and zinc is listed as an excipient, so the zinc-to-peptide ratio is unspecified. Retrieved 24 August 2026.

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5. 5
   Peptide-Shop.com — ZINC THYMULIN 10 mg product listing (manufacturer: Russian Peptide)

   Second storefront carrying the identical specification and price, checked the same day as a cross-check on the first. Because both list the same manufacturer, these are two resellers of one source rather than two independent manufacturers — which is the honest reading of the availability evidence, and the reason no purity or content claim on this page is treated as independently confirmed. Retrieved 24 August 2026.

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6. 6
   Hair Therapy & Transplantation (2017) — An Analysis of the Safety and Efficacy of Topical Zinc-Thymulin to treat Androgenetic Alopecia

   The only human report on topical zinc thymulin, and the reason this page is written the way it is. Design as indexed: 18 consecutive adult subjects (17 male, 1 female), age range 35–90, Norwood 2–7, hair-loss duration 3–40 years; test compound synthesised by standard Fmoc peptide protocols and given in a water-based topical spray to the scalp; individual trial durations 4–10 months, 3,300 treatment days in total, with no adverse effects or local side effects reported. It is uncontrolled — no randomisation, no placebo, no blinding — it is not indexed in PubMed (searched 24 August 2026), and it is published in an OMICS / Longdom title (see the next reference). Its full text could not be retrieved on 24 August 2026: the publisher’s PDF endpoints returned HTTP 520 and 404 on every mirror attempted and the repository copy returned 403. Only the details above, confirmable from the indexed abstract, are reported on this page; no efficacy figure from it is quoted anywhere.

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7. 7
   US Federal Trade Commission (April 2019) — Court Rules in FTC’s Favor Against Predatory Academic Publisher OMICS Group; Imposes $50.1 Million Judgment

   Public record of why the journal name above carries no quality signal. A US federal district court ordered OMICS Group, its founder and two affiliated companies to pay more than $50.1 million to resolve FTC charges of deceptive claims about their conferences and publications. Among the practices found: deceptively claiming that the journals provided rigorous peer review and had editorial boards of prominent academics, hiding substantial publication fees until after acceptance, and falsely claiming that the journals were listed in reputable databases such as PubMed. This does not establish that any particular article is wrong; it does remove the usual reason to give a published paper the benefit of the doubt. Retrieved 24 August 2026.

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8. 8
   Journal of the American College of Nutrition (1988) — Zinc in growth and development and spectrum of human zinc deficiency

   Prasad AS. J Am Coll Nutr 1988;7(5):377–84 (PMID 3053862, DOI 10.1080/07315724.1988.10720255). Cited for one specific point: among the manifestations of mild human zinc deficiency the author lists decreased serum thymulin activity, alongside decreased serum testosterone, reduced lean body mass and decreased IL-2 activity. Independent confirmation, from the clinical side, that the zinc-thymulin relationship is a real physiological dependency rather than a marketing construct. Retrieved from PubMed, 24 August 2026.

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9. 9
   Journal of Investigative Dermatology (1995) — Role of the thymus gland in alopecia areata

   Fenton DA, Tobin DJ, Kendall MD. J Invest Dermatol 1995;104(5 Suppl):25S–26S (PMID 7738381, DOI 10.1038/jid.1995.45). A case-control study indexed under both thymulin and alopecia areata, cited here only to show that the thymus-hair question predates the peptide products by decades. It concerns alopecia areata, an autoimmune form of hair loss, and does not test thymulin as a treatment for pattern hair loss. Retrieved from PubMed, 24 August 2026.

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