Peptides / Immune and antimicrobial

Natural peptide · 9 amino acids · 858.9 Da

Thymulin (serum thymic factor)

Not approved

Thymulin is a natural nine-amino-acid peptide from the thymus that needs zinc to work, different from thymalin. It is not approved, and most studies are in animals, on the immune system, with a few small studies in people. PepBank shows 18 results on thymulin from 4 studies in people, and 607 from animal and lab studies. The strongest evidence is a randomized trial in people. Data as of 2026-10-30.

Also known as FTS, Facteur thymique serique, Serum thymic factor, Thymulin, Zinc thymulin, Nonathymulin

9 amino acids, from first to lastQAKSQGGSN

Evidence level: Mostly animal studies607 of 625 results come from studies in animals and lab cells. 4 studies in people.

Results in people

3% of 625 results

Results in animals

376

60% of 625 results

Results in lab cells

231

37% of 625 results

From computer models

0% of 625 results

Overview

Thymulin (serum thymic factor) at a glance

What it is	Natural peptide, 9 amino acids
Approval	Not approved for any use
In sport	Status unknown
Studies	183 studies with results. 150 of them gave thymulin, with 625 results. 18 in people376 in animals231 in lab cells
Best study in people	Randomized controlled trial with 40 people (1989)
Clinical trials	None registered
Community use	Hair loss

The science

What is thymulin?

A natural nine-residue thymic peptide whose biological activity depends on zinc. It is distinct from thymalin and thymosin-alpha-1.

Amino acids in one chain

Thymulin (serum thymic factor) structure and chemistry

The key facts about the molecule. Long codes are in the closed section below.

Sequence, 9 amino acidsFrom the first amino acid to the last

Q1A+KSQ5GGSN

Darker means more water-repelling+ and − show charge in the bodyOutlined: changed amino acid

Structure

Thymulin (serum thymic factor) is a natural peptide of 9 amino acids, with no ring, 1 changed amino acid.

Formula

C₃₃H₅₄N₁₂O₁₅

Molecular weight

858.9 g/mol

CAS number

63958-90-7

Development

Highest phase: phase 2.

Identifiers

PubChem 3085284, ChEMBL CHEMBL2106455, UNII 9H198D04WL

Full sequence, SMILES and InChIKey

InChIKey
LIFNDDBLJFPEAN-BPSSIEEOSA-N

SMILES
C[C@@H](C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CO)C(=O)N[C@@H](CCC(=O)N)C(=O)NCC(=O)NCC(=O)N[C@@H](CO)C(=O)N[C@@H](CC(=O)N)C(=O)O)NC(=O)[C@@H]1CCC(=O)N1

See charge, composition and 3D structure on the Scientific page

The evidence

What thymulin studies show

Results grouped by what the studies measured. Each card shows where its results come from.

Mostly animal studies607 of 625 results come from studies in animals and lab cells. 4 studies in people.

Immune system and inflammation

341 results · 9 in people · 200 animal · 132 lab

In rheumatoid arthritis trials, nonathymulin's clinical effect showed no clear associated changes in immune measurements. Annals of the rheumatic diseases, 1987

Top results

In rheumatoid arthritis trials, nonathymulin's clinical effect showed no clear associated changes in immune measurements. (Annals of the rheumatic diseases, 1987)
In mice, thymulin prevented IL-1 beta accumulation in blood after LPS exposure. (Immunological investigations, 2008)
In mice, FTS reduced the increase in lung weight compared with bleomycin alone. (Clinical and experimental immunology, 2001)

Daily life and fitness

3 results · 3 in people

In patients with multiple sclerosis, Nonathymulin did not significantly change disability scores compared with placebo. Acta neurologica Scandinavica, 1989

Top results

In patients with multiple sclerosis, Nonathymulin did not significantly change disability scores compared with placebo. (Acta neurologica Scandinavica, 1989)
In patients with multiple sclerosis, Nonathymulin did not significantly change the walking index compared with placebo. (Acta neurologica Scandinavica, 1989)
In patients with multiple sclerosis, Nonathymulin did not significantly change the function scale compared with placebo. (Acta neurologica Scandinavica, 1989)

Infections

11 results · 2 in people · 7 animal · 2 lab

In immunodeficient children, infections became less frequent during FTS treatment. Lancet, 1982

Top results

In immunodeficient children, infections became less frequent during FTS treatment. (Lancet, 1982)
In virus-infected mice, pancreatic virus levels were similar after FTS pretreatment and no treatment. (Archives of virology, 1996)
In immunodeficient children, infections became less severe during FTS treatment. (Lancet, 1982)

Bones and joints

6 results · 2 in people · 4 animal

In rheumatoid arthritis trials, nonathymulin 5 mg was the most effective tested dose and improved clinical status more than placebo. Annals of the rheumatic diseases, 1987

Top results

In rheumatoid arthritis trials, nonathymulin 5 mg was the most effective tested dose and improved clinical status more than placebo. (Annals of the rheumatic diseases, 1987)
In rheumatoid arthritis trials, nonathymulin 5 mg significantly improved clinical status as measured by four objective measures. (Annals of the rheumatic diseases, 1987)
In rats with arthritis, thymulin reduced paw swelling compared with control rats. (The Journal of rheumatology, 1997)

Sex hormones and fertility

57 results · 22 animal · 35 lab

In mice with the thymus removed, thymulin advanced puberty onset. The Journal of endocrinology, 2000

Top results

In mice with the thymus removed, thymulin advanced puberty onset. (The Journal of endocrinology, 2000)
In rats, thymulin did not change blood luteinizing hormone levels. (Journal of neuroendocrinology, 1992)
In normal and hypothymic mice, daily thymulin beginning at the later age delayed vaginal opening. (The Journal of endocrinology, 1999)

Cancer

17 results · 17 animal

In non-vaccinated rats, sarcomas occurred in 63.3% with FTS versus 76.7% without FTS. Leukemia, 1997

Top results

In non-vaccinated rats, sarcomas occurred in 63.3% with FTS versus 76.7% without FTS. (Leukemia, 1997)
In infected chickens, thymulin did not prevent visible tumors. (Veterinary microbiology, 1989)
In mice with tumors, thymulin reduced lung tumor colonies compared with saline. (Clinical & experimental metastasis, 1988)

All 4 studies in people

In people

In patients with multiple sclerosis, Nonathymulin did not significantly change disability scores compared with placebo.

1989Acta neurologica Scandinavica40 people

In people

In rheumatoid arthritis trials, nonathymulin's clinical effect showed no clear associated changes in immune measurements.

1987Annals of the rheumatic diseases

In people

In immunodeficient children, cellular immunity tests improved during FTS treatment.

1982Lancet3 people

In people

In two cancer patients with low initial activity, FTS increased peripheral natural killer activity compared with pretreatment.

1983International journal of immunopharmacology2 people

All 183 thymulin studies by area Open the Scientific page

Key thymulin studies

Studies in people come first, then studies in animals and in the lab.

People
Nonathymulin treatment of multiple sclerosis: double-blind pilot study
Roullet et al. 1989 · Acta neurologica Scandinavica · 40 people · cited by 0
4 results
People
Nonathymulin in rheumatoid arthritis: two double blind, placebo controlled trials
Amor et al. 1987 · Annals of the rheumatic diseases · cited by 3
5 results
People
Improvement of cellular immunity and IgA production in immunodeficient children after treatment with synthetic serum thymic factor (FTS)
Bordigoni et al. 1982 · Lancet (London, England) · 3 people · cited by 40
7 results
People
Effect of a synthetic thymic factor (facteur thymique serique) on natural killer cell activity in humans
Dokhelar et al. 1983 · International journal of immunopharmacology · 2 people · cited by 9
5 results
Animals
Augmentation with serum thymic factor of suppressive effects on retroviral tumor development in hosts immune to v-onc product
Miyauchi et al. 1997 · Leukemia · 60 subjects · cited by 2
6 results

All 183 Thymulin (serum thymic factor) studies

Thymulin clinical trials

ClinicalTrials.gov lists no trial of thymulin. A trial under another name may exist.

Status and safety

Is thymulin approved?

FDA

United States

Not approved

No approved medicine contains it.

EMA

European Union

Not approved

No approved medicine contains it.

WADA

Sport

Not recorded

Status unknown.

No. Not approved for any use. Its most advanced trial is in phase 2. The FDA, the EMA and the other sources we use show no approval (as of 21 Oct 2026). Status unknown.

Laws and labels change, so check the regulator for the current status.

Thymulin side effects and safety

PepBank has 17 safety results from studies of thymulin. 2 of them come from studies in people.

Safety results from studies (17)

In patients with multiple sclerosis, the Nonathymulin trial recorded no significant side effects. (Acta neurologica Scandinavica, 1989)
In rheumatoid arthritis trials, nonathymulin's clinical effect occurred with minimal adverse effects. (Annals of the rheumatic diseases, 1987)
In rats, thymulin injections increased sensitivity to heat pain. (Journal of neuroimmunology, 1998)
In rats, thymulin increased local sensitivity to pressure pain at doses as low as 0.5 ng. (Brain, behavior, and immunity, 1997)
In rats, thymulin lowered the pressure needed to cause pain. (Journal of neuroimmunology, 1997)
In thymectomized AKR mice, FTS did not change the overall frequency of leukemia after irradiation. (International journal of cancer, 1981)
In mice, FTS doses higher than 300 micrograms/day/mouse were not toxic. (Radiation research, 1992)
In rats, thymulin injections increased sensitivity to mechanical pain. (Journal of neuroimmunology, 1998)
In rats, thymulin increased local sensitivity to heat pain. (Brain, behavior, and immunity, 1997)
In rats, the highest thymulin dose shortened the pain response time to pressure in the noninjected paw. (Brain, behavior, and immunity, 1997)
In rats, the highest thymulin dose shortened the pain response time during immersion of the noninjected paw. (Brain, behavior, and immunity, 1997)
In rats, thymulin lowered the heat needed to cause pain. (Journal of neuroimmunology, 1997)
In thymectomized AKR mice, FTS significantly increased early null leukemia after irradiation. (International journal of cancer, 1981)
In thymectomized AKR mice, FTS did not change late null leukemia frequency. (International journal of cancer, 1981)
In thymectomized AKR mice, FTS did not change the time to late null leukemia. (International journal of cancer, 1981)
In thymectomized AKR mice, FTS did not change B leukemia frequency. (International journal of cancer, 1981)
In thymectomized AKR mice, FTS did not change the time to B leukemia. (International journal of cancer, 1981)

See every safety result on the Scientific page

Doses studied (40 shown)

The doses that these studies used. They are not recommendations.

Dose as reported	Class	Species	Route	Duration	Design	Source
5 mg/day	Human	human	Not reported	Not reported	Randomized trial in people	Amor 1987
10 micrograms/kg every 3 days	Human	human	intravenous	Not reported	Reports of single patients · n = 2	Dokhelar 1983
100 ng/day	Animal	mouse	intraperitoneal	5 days	Study in live animals	Saha 1995
100 ng/kg daily	Animal	rat	subcutaneous	3 wk	Study in live animals	Henriques-Coelho 2008
15 microg/100 g body weight	Animal	mouse	injection	Not reported	Study in live animals	Lunin 2008
0.1, 0.5 and 1 microg in 5 microl saline	Animal	rat	intracerebroventricular	Not reported	Study in live animals	Safieh-Garabedian 2003
50 micrograms/administration	Animal	mouse	Not reported	day 2 and 1 before infection	Study in live animals	Mizutani 1996
10 micrograms	Animal	mouse	Not reported	Not reported	Study in live animals	Mizutani 1996
50 micrograms	Animal	mouse	Not reported	Not reported	Study in live animals	Mizutani 1996
15 μg per 100g of body weight	Animal	mouse	intraperitoneal	30 days	Study in live animals	Lunin 2013
12 ng/g body weight	Animal	mouse	Not reported	Not reported	Study in live animals	García 2000
50 micro g/head before LPS and 50 micro g/head immediately before LPS	Animal	mouse	intraperitoneal	Not reported	Study in live animals	Saitoh 2004
5 microg/100 microl	Animal	mouse	intraperitoneal	Not reported	Study in live animals	Talhouk 2000
5 ng intraplantar or 50 ng intraperitoneal	Animal	rat	intraplantar or intraperitoneal	Not reported	Study in live animals	Saadé 1998
0.1 and 10 μg/kg	Animal	rat	intraperitoneal	Not reported	Study in live animals	Buckingham 1992
5, 50, and 250 microg/kg/day	Animal	rat	subcutaneous	28 days	Study in live animals	Tada 2002
5cH	Animal	chicken	drinking water	1st to 42nd day of life	Study in live animals	Sato 2012
200 ng	Animal	mouse	Not reported	Not reported	Study in live animals	Hinojosa 1999
0.5 ng	Animal	rat	intraplantar	Not reported	Study in live animals	Safieh-Garabedian 1997
10 ng	Animal	rat	intraplantar	Not reported	Study in live animals	Safieh-Garabedian 1997
5 ng	Animal	rat	intraplantar	Not reported	Study in live animals	Safieh-Garabedian 1997
0.2 microgram/day	Animal	mouse	intramuscular	4 weeks	Study in live animals	Barbul 1989
up to 5 micrograms/kg body wt.	Animal	rat	injection	Not reported	Study in live animals	Goya 1987
20-150 ng	Animal	rat	intraperitoneal	Not reported	Study in live animals	Safieh-Garabedian 1997
0.15mg/kg e.o.d	Animal	mouse	intraperitoneal	Not reported	Study in live animals	Lunin 2015
0.05 and 5.0 ng/100 g body weight daily	Animal	chicken	Not reported	from hatching until 4 weeks of age	Study in live animals	Chandratilleke 2000
1 and 10 microg	Animal	rat	intravenous	Not reported	Study in live animals	Wise 1998
30 micrograms/100 g body weight	Animal	Hartley guinea pig and Lewis rat	subcutaneous	days -1, 4, 9 and 15	Study in live animals	Kato 1988
1-6600 micrograms/kg	Animal	rat	intravenous	Not reported	Study in live animals	Yamanouchi 1994
40-50 micrograms/kg	Animal	rat	intravenous	1 min before alloxan injection	Study in live animals	Yamanouchi 1994
5cH	Animal	mouse	oral	60 days	Study in live animals	Rodrigues 2014
5CH, 1.6 × 10(-17) M	Animal	mouse	drinking water	Not reported	Study in live animals	Bonamin 2013
10 ng three times weekly	Animal	mouse	Not reported	until rejection	Study in live animals	Kaiserlian 1981
50 ng/100 g body weight	Animal	chicken	injection	Not reported	Study in live animals	Oliver 2003
1 mug/mouse/day	Animal	mouse	subcutaneous	Not reported	Study in live animals	Sun 2007
1, 100, and 1000 ng	Animal	mouse	intraperitoneal	Not reported	Study in live animals	Kanaan 2002
1 microg	Animal	mouse	intraperitoneal	Not reported	Study in live animals	Kanaan 2002
1 ng/kg	Animal	mouse	Not reported	3 days	Study in live animals	Okamoto 1993
1 ng-1 microgram/kg	Animal	mouse	Not reported	3 days	Study in live animals	Okamoto 1993
0.01 microgram per injection	Animal	mouse	subcutaneous	2 or 3 weeks	Study in live animals	Tomazic 1988

From the community

How people use it

What people report online. It comes from forums and guides, not from studies.

Community-reported. Not tested in trials.

A community guide describes topical zinc-thymulin use for hair loss. It states that reliable community dosing data are sparse.

Reported routines and cautions

What people use it for

Hair lossS1

Reported regimens

Regimens that community sources report for Thymulin. Community-reported, not tested in trials.
Context	Route	Amount	How often	How long	Agreement	Sources
Emerging topical zinc-thymulin reports	topical scalp application	Not stated	daily	Not stated	Single source. The source carries seller advertisements or affiliate links.	S1

Cautions

The guide states that concentrations across commercial products are not standardized and reliable community reports are limited.S1

Community sources

S1Thymulin and hair loss, Peptidingspeptidings.comcarries seller links, not linked

Gaps

No standardized community amount or concentration was established. The source also discusses trials, whose doses are not copied into this regimen.

Questions and more

Ask a question about thymulin

The answer links to every study it uses.

What does the evidence say about thymulin?Is thymulin tested in people?Compare with Thymosin alpha-1 Compare with Vasoactive intestinal peptide (VIP, aviptadil)

Sources

Database: PepBank data for thymulin (data version 308560)
Regulator: FDA status record
Regulator: EMA status record
Regulator: WADA status record
Community: community sources (forums and guides), as summarized in the PepBank community file

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

PepBank is a research reference. Talk to a doctor before you use any peptide.

Ask your AI about thymulin

Curo is a peptide shop. PepBank and Curo have the same owner. See the Curo catalog (opens in a new tab).

Thymulin (serum thymic factor)

Not approved

Also known as FTS, Facteur thymique serique, Serum thymic factor, Thymulin, Zinc thymulin, Nonathymulin

What it is

Natural peptide, 9 amino acids

Approval

Not approved for any use

In sport

Status unknown

Studies

183 studies with results. 150 of them gave thymulin, with 625 results.
18 in people376 in animals231 in lab cells

Best study in people

Randomized controlled trial with 40 people (1989)

Clinical trials

None registered

Community use

Hair loss

Dose as reported

Class

Species

Route

Duration

Design

Source

5 mg/day

Human

human

Not reported

Randomized trial in people

Amor 1987

10 micrograms/kg every 3 days

Human

human

intravenous

Not reported

Reports of single patients · n = 2

Dokhelar 1983

100 ng/day

Animal

mouse

intraperitoneal

5 days

Study in live animals

Saha 1995

100 ng/kg daily

Animal

rat

subcutaneous

3 wk

Study in live animals

Henriques-Coelho 2008

15 microg/100 g body weight

Animal

mouse

injection

Not reported

Study in live animals

Lunin 2008

0.1, 0.5 and 1 microg in 5 microl saline

Animal

rat

intracerebroventricular

Not reported

Study in live animals

Safieh-Garabedian 2003

50 micrograms/administration

Animal

mouse

Not reported

day 2 and 1 before infection

Study in live animals

Mizutani 1996

10 micrograms

Animal

mouse

Not reported

Study in live animals

Mizutani 1996

50 micrograms

Animal

mouse

Not reported

Study in live animals

Mizutani 1996

15 μg per 100g of body weight

Animal

mouse

intraperitoneal

30 days

Study in live animals

Lunin 2013

12 ng/g body weight

Animal

mouse

Not reported

Study in live animals

García 2000

50 micro g/head before LPS and 50 micro g/head immediately before LPS

Animal

mouse

intraperitoneal

Not reported

Study in live animals

Saitoh 2004

5 microg/100 microl

Animal

mouse

intraperitoneal

Not reported

Study in live animals

Talhouk 2000

5 ng intraplantar or 50 ng intraperitoneal

Animal

rat

intraplantar or intraperitoneal

Not reported

Study in live animals

Saadé 1998

0.1 and 10 μg/kg

Animal

rat

intraperitoneal

Not reported

Study in live animals

Buckingham 1992

5, 50, and 250 microg/kg/day

Animal

rat

subcutaneous

28 days

Study in live animals

Tada 2002

5cH

Animal

chicken

drinking water

1st to 42nd day of life

Study in live animals

Sato 2012

200 ng

Animal

mouse

Not reported

Study in live animals

Hinojosa 1999

0.5 ng

Animal

rat

intraplantar

Not reported

Study in live animals

Safieh-Garabedian 1997

10 ng

Animal

rat

intraplantar

Not reported

Study in live animals

Safieh-Garabedian 1997

5 ng

Animal

rat

intraplantar

Not reported

Study in live animals

Safieh-Garabedian 1997

0.2 microgram/day

Animal

mouse

intramuscular

4 weeks

Study in live animals

Barbul 1989

up to 5 micrograms/kg body wt.

Animal

rat

injection

Not reported

Study in live animals

Goya 1987

20-150 ng

Animal

rat

intraperitoneal

Not reported

Study in live animals

Safieh-Garabedian 1997

0.15mg/kg e.o.d

Animal

mouse

intraperitoneal

Not reported

Study in live animals

Lunin 2015

0.05 and 5.0 ng/100 g body weight daily

Animal

chicken

Not reported

from hatching until 4 weeks of age

Study in live animals

Chandratilleke 2000

1 and 10 microg

Animal

rat

intravenous

Not reported

Study in live animals

Wise 1998

30 micrograms/100 g body weight

Animal

Hartley guinea pig and Lewis rat

subcutaneous

days -1, 4, 9 and 15

Study in live animals

Kato 1988

1-6600 micrograms/kg

Animal

rat

intravenous

Not reported

Study in live animals

Yamanouchi 1994

40-50 micrograms/kg

Animal

rat

intravenous

1 min before alloxan injection

Study in live animals

Yamanouchi 1994

5cH

Animal

mouse

oral

60 days

Study in live animals

Rodrigues 2014

5CH, 1.6 × 10(-17) M

Animal

mouse

drinking water

Not reported

Study in live animals

Bonamin 2013

10 ng three times weekly

Animal

mouse

Not reported

until rejection

Study in live animals

Kaiserlian 1981

50 ng/100 g body weight

Animal

chicken

injection

Not reported

Study in live animals

Oliver 2003

1 mug/mouse/day

Animal

mouse

subcutaneous

Not reported

Study in live animals

Sun 2007

1, 100, and 1000 ng

Animal

mouse

intraperitoneal

Not reported

Study in live animals

Kanaan 2002

1 microg

Animal

mouse

intraperitoneal

Not reported

Study in live animals

Kanaan 2002

1 ng/kg

Animal

mouse

Not reported

3 days

Study in live animals

Okamoto 1993

1 ng-1 microgram/kg

Animal

mouse

Not reported

3 days

Study in live animals

Okamoto 1993

0.01 microgram per injection

Animal

mouse

subcutaneous

2 or 3 weeks

Study in live animals

Tomazic 1988

Context

Route

Amount

How often

How long

Agreement

Sources

Emerging topical zinc-thymulin reports

topical scalp application

Not stated

daily

Not stated

Single source. The source carries seller advertisements or affiliate links.

Thymulin (serum thymic factor)

Thymulin (serum thymic factor) at a glance

What is thymulin?

Thymulin (serum thymic factor) structure and chemistry

What thymulin studies show

Immune system and inflammation

Daily life and fitness

Infections

Bones and joints

Sex hormones and fertility

Cancer

All 4 studies in people

Key thymulin studies

Thymulin clinical trials

Is thymulin approved?

Thymulin side effects and safety

How people use it

What people use it for

Reported regimens

Cautions

Community sources

Ask a question about thymulin

Related peptides

Sources

Thymulin (serum thymic factor)

Thymulin (serum thymic factor) at a glance

What is thymulin?

Thymulin (serum thymic factor) structure and chemistry

What thymulin studies show

Immune system and inflammation

Daily life and fitness

Infections

Bones and joints

Sex hormones and fertility

Cancer

All 4 studies in people

Key thymulin studies

Thymulin clinical trials

Is thymulin approved?

Thymulin side effects and safety

How people use it

What people use it for

Reported regimens

Cautions

Community sources

Ask a question about thymulin

Related peptides

Sources