Thymulin_Dosage, benefits & legal status
Also known as serum thymic factor, FTS, facteur thymique serique, zinc thymulin
A thymus peptide studied for immune balance and calming inflammation.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is Thymulin?
Plain language first. The technical label stays, but it never stands alone.Overview
It is studied for balancing immune function and calming inflammation and pain. Human data is limited.
Thymulin is a zinc-dependent thymus peptide involved in immune-cell maturation.
What it's used for
A thymus peptide studied for balancing immune function and calming inflammation and pain.
How does Thymulin work?
What it does in the body, and where.Thymulin only works when bound to zinc. Without it the molecule is inactive, which makes it unusual and makes zinc status directly relevant.
- 01It requires zinc to become activeThe peptide and the mineral together form the working molecule.
- 02It helps immune cells matureParticularly T cells, in the thymus.
- 03It has shown pain and inflammation effects in animalsSeparate from its immune role, and the reason for some of the current interest.
- 04Human data is limitedMostly observational work on declining levels with age.
A schematic of the compound's mechanism, not a diagnostic image.
What else is it used for?
Each use below carries its own evidence level. Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.
- Immune balance and calming inflammationResearch only
- Pain reductionResearch only
The published record
581
Records indexed for Thymulin401 papers and 0 trials indexed in detail.
152 in humans, 104 of them original studies.
FDA: Category 3.
Counted from Europe PMC indexing, not read by a person. Human means indexed under humans, which includes reviews and work on human cells. Original studies exclude reviews and lab work on human cells.Last updated 12 September 2026.
At a glance
Four things to know about Thymulin
Evidence
Research only
Category
Immune support
Common vial
10 mg
Half-life
Nothing published
How much, and do you cycle it?
The range, and whether you take breaks.1 mg per dose, daily/weekly. No established scheduleNo range
No published study has established how long to take this or whether a break is needed. Schedules quoted online come from vendors and forums, and different sources disagree.
How long does it stay in the body?
The half-life, and where the figure comes from.Nothing publishedNo figure
No half-life has ever been published for any of the Russian bioregulator peptides, in people or in animals. The research behind them, mostly from one group in St Petersburg, measures effects on tissue, gene activity and lifespan. None of it measures how long the peptide stays in the body.
You can compare this against the whole library to see where it sits.
How do I dose and price it?
Enter your vial and your dose. Pick a mix. We show the draw and the cost.The vial holds a fixed amount of drug. Adding more water does not make more drug, it just spreads it thinner, so you draw a bigger number on the syringe for the same dose.
Choose your mix
Measuring the water1 mL = one full 100-unit syringe.
Your draw
20 / 100 unitsThymulin starts at $45.00 across 7 vendors, typically $4.20 – $9.00 per mg.
10 listings, last read Sep 5, 2026. Shipping and card fees are not included.
How do you store it?
Before mixing, and after.Dry powder in the freezer or fridge. Once mixed, fridge, and use within about a month.
Unmixed lyophilized Thymulin keeps for a long time cold. Once you add water the clock starts: most reconstituted vials hold up for roughly 28 to 30 days at fridge temperature. Keep it out of light, and do not freeze it after mixing.
What are the side effects and cautions?
Known cautions and warnings for this compound.Who should avoid it
- No controlled human safety trials exist
- Pregnancy
Stop and get help
- Signs of an allergic reaction
- Anything unusual, given the absence of human data
Common effects
- Unknown in humans. Studied mainly in laboratory and animal settings
What regulators say
- FDA: Bulk Drug Substances Nominated for Use in Compounding Under Section 503A (interim categories 1, 2, 3), updated May 14, 2026Category 3
Listed as Thymulin acetate
Checked 11 September 2026
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is Thymulin approved?
And where the numbers on this page come from.No. Thymulin is not approved for any use, anywhere. It is sold labelled for laboratory research only, and there is no legal route to buy it for human use.
- Approval statusResearch only
- RouteUnder the skin (subcutaneous)
- CheckedAugust 2026
What has happened recently
We have not yet written a full regulatory note for this compound. The status above is current as of the date shown.
You can compare this against the whole library, or read how to check a seller.
- DoseFrom research and community reports. No regulator has reviewed this dose.
- Vial sizeFrom what vendors typically list; not a recommendation.
- Sources
- Reviewed14 August 2026
What else is like Thymulin?
Others in Immune support, side by side.If you're weighing Thymulin, it's worth reading Thymogen, Thymopentin (TP-5), and Imunofan in the same class.
A thymus peptide studied for immune balance and calming inflammation.
- Dose
- 1 mg per dose
- How often
- Daily/weekly
A short immune bioregulator taken in courses, with thin evidence.
- Dose
- Varies (course-based)
- How often
- Courses
Five amino acids that carry the whole activity of a thymus hormone.
- Dose
- 50 mg per dose
- How often
- 3x per week
A Russian rework of thymopentin, with one amino acid added at each end.
- Dose
- 50 mcg per dose
- How often
- Every other day, in courses
Guides for this compound
- How to Reconstitute a Peptide
Mix peptide powder with bacteriostatic water, step by step.
- How to Read an Insulin Syringe
Read the units, convert to millilitres, and draw the exact dose.
- mcg vs mg: The Peptide Dosing Mistake to Avoid
Your vial says mg and your protocol says mcg. Here is the conversion and how to check it.
- How to Read a Peptide COA
What the purity number does and does not tell you, and how to spot an edited report.
- How to Vet a Peptide Vendor
Independent COAs, HPLC purity, and the red flags that mean walk away.
Sources
- Prasad et al., Serum thymulin in human zinc deficiency (Journal of Clinical Investigation)(1988)Thymulin is a real molecule with real human data, and this is the paper that establishes it, with Bach and Dardenne, who discovered the peptide, as co-authors. Read what was actually measured. Serum thymulin activity was assayed in three small groups: two volunteers made mildly zinc-deficient by diet, six adults with sickle cell anaemia, and six adults without it. Activity fell with mild zinc deficiency and was restored by adding zinc, both in the subjects and in the test tube, which is what makes serum thymulin a sensitive marker of zinc status. Nobody in this study was given thymulin. The substance administered was zinc, and the peptide being measured was the subject's own. That distinction matters when the compound is sold as an injection, because the human literature here describes a body's existing thymulin responding to a mineral, not an injected peptide doing anything.
- FDA, Bulk drug substances nominated for use in compounding under section 503A, updated 14 May 2026(2026)Thymulin acetate appears on this list, in category 3, which FDA titles bulk drug substances nominated without adequate support. Somebody asked for thymulin to be permitted in compounded medicines and the agency's position is that the nomination came without enough information to evaluate it. That sits comfortably alongside the human evidence on this page, which measures the body's own thymulin as a marker of zinc status rather than testing an injection. Note the ingredient named is the acetate salt, and note also that category 3 is not a safety finding; category 2 is where FDA places substances raising significant safety risks, and thymulin is not there.
Last reviewed 14 August 2026
Beyond these, 401 records are indexed. Browse the records