Thymus Extract
Also called thymomodulin, calf thymus extract, bovine thymus, thymus glandular, Leucotrofina.
Best grade D across 6 graded outcomes Other Last checked
The short answer
From 10 sourcesThymus extract comes from calf thymus. Most human data are small 1980s and 1990s trials of one Italian product, thymomodulin, reporting fewer respiratory infections and allergy flares (grade D). A 1998 placebo-controlled trial of an over-the-counter thymic extract found no effect in hepatitis C. Most abstracts omit key details, and no long-term safety data exist.
Every graded outcome on this page
6 rows · line = participants- DGrade DNumber and duration of respiratory infections in adultsRespiratory infectionsn 85
- DGrade DImmune markers during intensive trainingExercisen 60
- DGrade DLiver enzymes and HBsAg clearance in acute hepatitis BHepatitisn 50
- DGrade DHepatitis C virus levelsHepatitisn 32
- DGrade DAtopic dermatitis flare on food challenge after an elimination dietAllergyn 19
- DGrade DAirway hyperresponsiveness to methacholine in asthmaAsthman 16
- 3 more graded outcomes, in the evidence chapter
Key facts
- What it is
- A calf thymus derivative; thymomodulin is an acid lysate made of peptides of 1 to 10 kD1
- Respiratory infections
- Small 1980s trials reported fewer infections in children (versus placebo) and in adults (120 mg/day, versus other regimens)23
- Allergy and asthma
- Two trials of 16 and 19 people reported less airway reactivity and fewer eczema flares on food challenge45
- Hepatitis C
- A 1998 placebo-controlled trial of an over-the-counter oral thymic extract in 38 people with hepatitis C found no change in virus levels10
- Class evidence in COPD
- A 2022 Cochrane review pooled 36 immunostimulant trials, thymomodulin among them, and found a modest drop in flare-ups for the class as a whole8
- Modern products
- No trial in our sources tested today's raw or freeze-dried thymus glandulars1
What it is
Thymus extract is made from calf thymus gland. The studied form, thymomodulin, is an acid lysate of thymus peptides taken by mouth.
How it works
ProposedThymomodulin is a mix of thymus peptides. Animal and cell studies reported that it affects the maturation and function of T lymphocytes and, possibly indirectly, B cells and white-cell production. In human trials, marker changes included higher salivary IgA, a higher T-helper to suppressor ratio and lower IgE.1246
Forms, side by side
2 forms named in our sources. The rest show what our data holds, and say plainly where it holds nothing yet.
Thymus Extract forms compared
2 forms| 2 forms | Thymomodulin (calf thymus acid lysate) | Bovine thymus glandular (raw or freeze-dried tissue) |
|---|---|---|
| Absorption in people | No human absorption data in our sources; its maker described it as prepared to stay active when taken by mouth.1 | No human data in our sources. |
| GI tolerance | Animal studies showed little or no toxicity at high doses; the cited trial abstracts do not report adverse effects.1 | No trial in our sources tested whole-tissue thymus glandulars.1 |
| Studied for | Recurrent respiratory infections, food allergy, asthma, hepatitis B and athletes (80 to 120 mg/day) | No human trials in our sources |
- Thymomodulin (calf thymus acid lysate)
- Absorption in people
- No human absorption data in our sources; its maker described it as prepared to stay active when taken by mouth.1
- GI tolerance
- Animal studies showed little or no toxicity at high doses; the cited trial abstracts do not report adverse effects.1
- Studied for
- Recurrent respiratory infections, food allergy, asthma, hepatitis B and athletes (80 to 120 mg/day)
- Bovine thymus glandular (raw or freeze-dried tissue)
- Absorption in people
- No human data in our sources.
- GI tolerance
- No trial in our sources tested whole-tissue thymus glandulars.1
- Studied for
- No human trials in our sources
What the human research says
Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.
Trial map
6 graded outcomes, largest study first6 graded outcomes: 3 improved, 2 mixed, 1 no effect. The largest, a 1987 open-label trial of 85 people on number and duration of respiratory infections in adults, found an improvement.
1Number and duration of respiratory infections in adults
Improved · Grade D · Open-label trial, 85 people, 1987
Adults with recurrent respiratory infections (Italian-language report)
Dose, result and source| Outcome | Found | People | Study | Who was studied |
|---|---|---|---|---|
| Number and duration of respiratory infections in adults | Improved | 85 | Grade D · Open-label trial, 1987 | Adults with recurrent respiratory infections (Italian-language report) |
| Immune markers during intensive training | Mixed | 60 | Grade D · RCT, 1995 | Athletes in regular intensive training |
| Liver enzymes and HBsAg clearance in acute hepatitis B | Mixed | 50 | Grade D · RCT, 1985 | Inpatients with acute hepatitis B |
| Hepatitis C virus levels | No effect | 32 | Grade D · RCT, 1998 | Adults with chronic hepatitis C who had not responded to or could not tolerate interferon (US tertiary centre) |
| Atopic dermatitis flare on food challenge after an elimination diet | Improved | 19 | Grade D · RCT, 1989 | Children with food allergy and atopic dermatitis |
| Airway hyperresponsiveness to methacholine in asthma | Improved | 16 | Grade D · RCT, 1989 | Atopic adults with asthma |
Every graded row
6 rowsShowing 6 of 6 outcomes. Human trials only.
DGrade DNumber and duration of respiratory infections in adultsRespiratory infectionsImprovedOpen-label trial
n 85 · 1987
Improved Thymomodulin alone or with a vaccine cut the number and length of infections and antibiotic use more than antibiotic or vaccine regimens. Lung function and lab values did not change.
- Design
- Open-label trial, n = 85, 1987
- Population
- Adults with recurrent respiratory infections (Italian-language report)
- Form
- Thymomodulin, alone or with a bacterial vaccine
- Dose
- 120 mg/day for 20 days a month
- Duration
- 4 months
- Source
- Reference 3 · PubMed 3670682 (opens PubMed)
DGrade DImmune markers during intensive trainingExerciseMixedRCT
n 60 · 1995
Mixed Training lowered immunoglobulins in all athletes; with thymomodulin, IgG2 did not fall and T-helper cells rose. No infection or performance outcome is reported in the abstract.
- Design
- RCT, n = 60, 1995
- Population
- Athletes in regular intensive training
- Form
- Thymomodulin
- Dose
- Not stated in the abstract
- Duration
- 3 months
- Source
- Reference 7 · PubMed 7601298 (opens PubMed)
DGrade DLiver enzymes and HBsAg clearance in acute hepatitis BHepatitisMixedRCT
n 50 · 1985
Mixed AST, ALT and HBsAg clearance trended faster, but only the ALT decrease differed significantly from placebo.
- Design
- RCT, n = 50, 1985
- Population
- Inpatients with acute hepatitis B
- Form
- Thymomodulin oral ampoules
- Dose
- 1 ampoule twice daily vs placebo
- Duration
- 30 days
- Source
- Reference 6 · PubMed 3916838 (opens PubMed)
DGrade DHepatitis C virus levelsHepatitisNo effectRCT
n 32 · 1998
No effect Viral RNA levels at 3 months did not differ from placebo (3.48 vs 4.06 million copies/mL, P>0.2). All 19 people who completed 6 months stayed virus-positive, with levels similar to baseline.
- Design
- RCT, n = 32, 1998
- Population
- Adults with chronic hepatitis C who had not responded to or could not tolerate interferon (US tertiary centre)
- Form
- Complete Thymic Formula, an over-the-counter oral thymic extract product
- Dose
- Label dose of the commercial product (not stated in the abstract)
- Duration
- 3 months vs placebo, then up to 6 months
- Source
- Reference 10 · PubMed 9841585 (opens PubMed)
DGrade DAtopic dermatitis flare on food challenge after an elimination dietAllergyImprovedRCT
n 19 · 1989
Improved Skin improved in both groups on the diet. On food challenge, lesions stayed stable with thymomodulin but worsened with placebo, and IgE fell only with thymomodulin.
- Design
- RCT, n = 19, 1989
- Population
- Children with food allergy and atopic dermatitis
- Form
- Thymomodulin
- Dose
- 120 mg/day vs placebo, with an elimination diet
- Duration
- 90 days, then a 2-week food challenge
- Source
- Reference 4 · PubMed 2668397 (opens PubMed)
DGrade DAirway hyperresponsiveness to methacholine in asthmaAsthmaImprovedRCT
n 16 · 1989
Improved Airway responsiveness to methacholine was significantly reduced at 90 days with thymomodulin and stayed lower, though not significantly, 60 days after stopping.
- Design
- RCT, n = 16, 1989
- Population
- Atopic adults with asthma
- Form
- Thymomodulin
- Dose
- 80 mg/day vs placebo
- Duration
- 90 days
- Source
- Reference 5 · PubMed 2566293 (opens PubMed)
What the numbers add up to
Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.
Old, small and from one product
Class results are not product results
The Cochrane review's modest benefit in COPD covers 11 different immunostimulants pooled together, mostly bacterial extracts; it does not show that thymus extract alone works.8
Studied doses
Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.
Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.
Doses studied in human trials
Interactions and safety
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Interactions
0 agentsNone found in our sources.
Check with what you take
Kept on this device onlyAdd what you take. We list every interaction our evidence profiles cite between Thymus Extract and your picks, and between your picks.
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Add a supplement or medicine you take to check it against Thymus Extract.
Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.
Who should be careful
4 groups- Autoimmune conditions and immune-suppressing drugs
- Thymomodulin is described as an immune modulator acting on T cells, and none of the cited trials enrolled people with autoimmune disease or on immune-suppressing drugs, so there are no data for them.1
- Beef allergy or avoidance
- Thymus extracts are made from calf thymus tissue.1
- Animal-tissue sourcing (BSE)
- Thymus products are made from cattle tissue. To limit the risk of bovine spongiform encephalopathy (mad cow disease), FDA bars brain, spinal cord and other specified risk materials, and material from disabled or uninspected cattle, from dietary supplements; FDA describes the remaining risk from regulated foods as negligible.9
Reading the label, and the cost per dose
Compare any product you already have by the amount it delivers, not by capsule count or front-of-pack weight.
How to read the label
2 checksThymomodulin vs glandulars
Check the cattle source
Because glandulars are animal tissue, a label or maker statement on where the cattle came from and that they were inspected is worth looking for; FDA rules bar material from uninspected or disabled cattle.9
Have the bottle? Photograph its Supplement Facts panel and see each line, thymus extract included, beside the doses and forms the trials used in Label X-Ray.
Cost per studied dose, without the sales pitch
Your numbers, no product dataEnter the price, servings and the amount per serving from your label.
Frequently asked questions
Short answers to common questions; the numbers link to the sources below.
Common questions
6 answersDoes thymus extract boost immunity?
Does thymus extract help hepatitis?
Does thymus extract help allergies or asthma?
Is thymus extract safe?
Animal studies found little toxicity, but the trial abstracts do not report adverse effects in detail, and there are no long-term human safety data. No drug-interaction studies were found, so data on use with medicines are lacking.1
Is thymomodulin the same as a thymus glandular?
No. Thymomodulin is a standardized acid lysate of calf thymus peptides. Raw or freeze-dried glandulars are unstandardized and were not tested in the trials in our sources.1
Sources
10 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.
Sources cited on this page
10 sources- 1Update and future perspectives of a thymic biological response modifier (Thymomodulin).Review Immunopharmacol Immunotoxicol, 1987 · PMID 3325544
- 2A double-blind clinical trial for the evaluation of the therapeutical effectiveness of a calf thymus derivative (Thymomodulin) in children with recurrent respiratory infections.RCT Thymus, 1986 · PMID 3544353
- 3[Prevention of recurrent respiratory infections in adults].Open-label trial Minerva Med, 1987 · PMID 3670682
- 4"Food allergy in children: an attempt to improve the effects of the elimination diet with an immunomodulating agent (thymomodulin). A double-blind clinical trial".RCT Immunopharmacol Immunotoxicol, 1989 · PMID 2668397
- 5Long-term treatment with thymomodulin reduces airway hyperresponsiveness to methacholine.RCT Ann Allergy, 1989 · PMID 2566293
- 6Attempt to treat acute type B hepatitis with an orally administered thymic extract (thymomodulin): preliminary results.RCT Drugs Exp Clin Res, 1985 · PMID 3916838
- 7Immunological patterns during regular intensive training in athletes: quantification and evaluation of a preventive pharmacological approach.RCT J Int Med Res, 1995 · PMID 7601298
- 8Immunostimulants versus placebo for preventing exacerbations in adults with chronic bronchitis or chronic obstructive pulmonary disease.Systematic review Cochrane Database Syst Rev, 2022 · PMID 36373977
- 9FDA Announces Final Rule on Bovine Spongiform EncephalopathySafety communication U.S. Food and Drug Administration, 2016 · fda.gov
- 10Oral thymic extract for chronic hepatitis C in patients previously treated with interferon. A randomized, double-blind, placebo-controlled trial.RCT Ann Intern Med, 1998 · PMID 9841585
What changed
Every dated change to this page: what changed, who made it and why.
Change log
4 entries| Date | Change | Who and why |
|---|---|---|
| evidence, key facts, FAQ, summary, related links | Added a 1998 placebo-controlled trial of an over-the-counter oral thymic extract in chronic hepatitis C (PMID 9841585, no effect, grade D). PubMed searched for thymus-extract and thymomodulin RCTs and meta-analyses through 2026: nothing newer qualifies. Interactions checked: no entry in LiverTox or LactMed and no published interaction study found, so the list stays empty and the safety FAQ now says interaction data are lacking. New hepatitis FAQ; related links to echinacea and the immune hub. Fact-checked against the sources; corrected: the 1998 hepatitis C product is described as an herbal dietary supplement, as in the abstract, not as a multi-ingredient product. | Writer: Kymata Health EditorialTrigger: A–Z page audit |
| safety | Independent review: added a BSE / animal-tissue sourcing safety note and label tip based on FDA's 2016 final rule on cattle materials. | Writer: Kymata Health EditorialTrigger: review |
| all | First draft. Every PMID checked against NCBI E-utilities esummary (title and year taken from the record) and abstracts read for every cited row. | Writer: Kymata Health EditorialTrigger: new page |
| all | Adversarial review pass: every evidence row's numbers machine-checked against its PubMed abstract, retraction and erratum flags checked for all PMIDs, unverified country and affiliation details removed, and claims not supported by the cited abstracts reworded or dropped. | Writer: Kymata Health EditorialTrigger: review |
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