Peptide education
Thymulin
Serum thymic factor · Facteur thymique serique · FTS · Nonathymulin
Thymulin is a nine-amino-acid thymic peptide associated with zinc-dependent biological activity. A synthetic serum thymic factor has also been studied under the name nonathymulin.
Older disease-specific trials reported a signal in rheumatoid arthritis and no significant benefit in a multiple sclerosis pilot. Neither establishes a general immune-support treatment or long-term product safety.
Overview
Quick answer
Studies that measured the body's own thymulin after zinc supplementation did not necessarily give thymulin to participants. Older trials did administer synthetic serum thymic factor, so it would be incorrect to say no human intervention has been studied.
Is thymulin the same as thymalin?
Do not assume so. Thymulin is a defined nonapeptide, while the named Thymalin product in the manufacturer's information is a thymus extract. The identity of any separate product needs its own verification.
Has synthetic serum thymic factor been studied in people?
Yes. Older placebo-controlled trials studied nonathymulin in rheumatoid arthritis and multiple sclerosis. Their results were not the same and do not prove a broad immune-support effect.
Does a zinc study prove thymulin treatment works?
No. In the cited zinc-deficiency study, researchers gave zinc and measured endogenous serum thymulin activity. That is different from testing administered thymulin.
Evidence
Evidence snapshot
In the first trial, the authors reported more global improvement with the 5 mg schedule than with placebo.
A 40-patient pilot did not find significant differences on the reported disability and function scales.
The human intervention in the cited study was zinc, not thymulin.
Claims
Common claims vs evidence
| Claim | Human evidence | Mechanistic evidence | Verdict |
|---|---|---|---|
| No human study has administered synthetic serum thymic factor. | Older controlled studies administered nonathymulin to patients with rheumatoid arthritis or multiple sclerosis. | The claim is incorrect for the studies cited here; their results are disease-specific and limited. | |
| Restoring thymulin activity with zinc proves injected thymulin improves immunity. | The cited study supplemented zinc and measured endogenous thymulin activity in small groups. | The peptide binds zinc and zinc affects activity in laboratory assays. | A zinc intervention and a thymulin intervention answer different questions. |
Bottom line
Main takeaway
Thymulin is a defined peptide, but broad immune-support claims are not established by these studies.
A peptide component, its zinc complex, and a thymus extract are not interchangeable specifications.
Separate administered nonathymulin trials from zinc interventions measuring endogenous activity.
Identity
What it is
Thymulin is a nonapeptide associated with the thymus; synthetic serum thymic factor was studied as nonathymulin.
Research
Research evidence
The cited older rheumatoid arthritis trials reported a clinical signal at one studied amount, while a multiple sclerosis pilot did not show significant improvement. Separately, a small zinc-deficiency study measured endogenous thymulin rather than administering it.
| Study / evidence area | Population | Design | Product context | Main outcome | Limitations | Weight |
|---|---|---|---|---|---|---|
| Rheumatoid arthritis trials | 49 patients in the first trial and 30 in the second, all with rheumatoid arthritis | Two randomized, double-blind, placebo-controlled trials | Synthetic thymic peptide called nonathymulin | The abstract reported global improvement in 56% of the 5 mg group versus 17% with placebo. The full report described patient-assessed moderate or major improvement in 10 of 16 versus 3 of 17 in the first trial, without clear changes in measured immunological parameters. | The abstract and full report give different improvement percentages; the small, disease-specific trials need confirmation. | Older disease-specific controlled evidence |
| Multiple sclerosis pilot | 40 matched patients with multiple sclerosis and moderate disability; the authors described the disease as evolving over time | Randomized, double-blind, placebo-controlled pilot | Subcutaneous nonathymulin for 6 months | Disability, ambulation, and functional scales did not differ significantly between groups. | Small pilot; the available abstract does not state the amount administered. | Older controlled pilot with no significant benefit |
| Human zinc-deficiency study | 14 participants across three small groups | Physiological study with zinc supplementation and laboratory assays | Zinc was the intervention; serum thymulin activity was measured. | Activity decreased with zinc deficiency and was restored with zinc in vivo or added to samples in vitro. | It did not test administered thymulin or establish a therapeutic regimen. | Human physiology, not a thymulin treatment trial |
Use context
Reported use context
The amounts below are historical study methods, not dosing recommendations.
Study and label context
The 1 mg and 5 mg groups received injections daily for 2 weeks, then 3 times a week, in a 6-month trial.
The 5 mg group showed a clinical signal; these results do not establish a wellness regimen.The 10 mg group received injections daily for 6 months.
Patient-assessed improvement was reported in 8 of 15 at 10 mg versus 5 of 15 with placebo; the difference was not significant.Patients received nonathymulin or placebo for 6 months, followed by 6 months of observation.
The available abstract does not specify an amount, and the measured outcomes did not significantly differ.Cautions
Safety and unknowns
- In the first rheumatoid arthritis trial, two of 16 patients assigned 5 mg withdrew after thrombocytopenia or vasculitis; the report does not establish that nonathymulin caused these events.
- In the second trial, one of 15 patients assigned 10 mg withdrew after low blood pressure and swelling of the larynx shortly after the first injection; another withdrew because of injection pain. The report does not establish causation.
- The older trials cannot establish long-term safety or detect all uncommon adverse effects.
- Safety and identity of a modern product cannot be inferred from an older study preparation.
- The peptide component and a zinc-containing complex have different product specifications.
Product quality
Product identity and quality
Thymulin, its zinc complex, and thymus extracts should not be assumed to be the same preparation.
Peptide identity
Similar thymus-related names can refer to different substances.
Zinc and formulation
The peptide and its metal complex are different specifications.
Product quality
A study citation does not verify a separate product's contents or sterility.
Mechanism
How it is proposed to work
Thymulin binds zinc and has been studied in assays related to immune-cell activity.
Laboratory binding experiments found one zinc ion associated with the nonapeptide under the reported conditions.
Details
Technical details
Sources
References
- 1.
PubChem. Thymulin chemical record
Chemical record for the nonapeptide; peptide identity and zinc complex are distinct product specifications.
- 2.
Other. Thymalin product information
Manufacturer information identifies its Thymalin product as a thymus extract, not a defined thymulin preparation.
- 3.
PubMed. Zinc binding to serum thymic factor
doi:10.1016/0304-4165(84)90116-8 PMID:6538097
Laboratory study of zinc binding and activity in an in vitro assay.
- 4.
PubMed. Nonathymulin in rheumatoid arthritis: two placebo-controlled trials
doi:10.1136/ard.46.7.549 PMID:3310925
Two older randomized trials of synthetic thymic peptide; the full report describes different schedules and a global assessment.
- 5.
PubMed. Nonathymulin in multiple sclerosis: double-blind pilot study
doi:10.1111/j.1600-0404.1989.tb03929.x PMID:2618585
Randomized placebo-controlled pilot in 40 patients; nonathymulin is described as synthetic serum thymic factor.
- 6.
PubMed. Serum thymulin in human zinc deficiency
doi:10.1172/JCI113717 PMID:3262625
Small human zinc-deficiency study; zinc was supplemented and endogenous thymulin activity measured.
- 7.
FDA. FDA Drugs@FDA database scope and nonathymulin search
An editorial search of the openFDA Drugs@FDA active-ingredient field for the full name nonathymulin returned no match. The FDA overview links to the search but is not a saved result; alternative names and indexing limit the finding.
- 8.
FDA. FDA Drugs@FDA database scope and thymulin search
An editorial search of the openFDA Drugs@FDA active-ingredient field for the full name thymulin returned no match. The FDA overview links to the search but is not a saved result; a name query is not an exhaustive legal determination.