TB-500 (Thymosin Beta-4 Fragment)

Synthetic Fragment (17-23) of Thymosin Beta-4

Weight: 4,963.44 Da
Half-life: ~2 hours
Chain: 43 amino acids
6 studies
2022 latest
3 recent
Well Studied
Dose 2-5mg per injection (higher doses for serious injuries)
Frequency 2-3x weekly (e.g., Monday, Wednesday, Friday)
Cycle 6-8 weeks for active healing
Storage Reconstituted: 2-8°C, use within 28 days
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A synthetic 7-amino acid fragment corresponding to the actin-binding region of thymosin beta-4, originally developed for equine use with retained tissue repair properties. TB-500 acts as principal actin-sequestering protein, regulating cell migration, promoting angiogenesis, reducing inflammation, and activating stem cell differentiation.

Mechanism of Action

Acts as principal actin-sequestering protein, regulating cell migration, promoting angiogenesis, reducing inflammation, and activating stem cell differentiation for comprehensive regenerative effects.

01 Superior systemic tissue repair
02 Accelerated muscle, tendon, and ligament healing
03 Enhanced cell migration and angiogenesis
04 Comprehensive regenerative effects
05 Neuroprotective properties

Molecular Data

Molecular Weight
4,963.44 Da
Chain Length
43 amino acids
Type
Thymosin fragment
Amino Acid Sequence
One-letter: ?SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES
H₂N
H
? 1
O ‖ C
N
S 2
O ‖ C
N
D 3
O ‖ C
N
K 4
O ‖ C
N
P 5
O ‖ C
N
D 6
O ‖ C
N
M 7
O ‖ C
N
A 8
O ‖ C
N
E 9
O ‖ C
N
I 10
O ‖ C
N
E 11
O ‖ C
N
K 12
O ‖ C
N
F 13
O ‖ C
N
D 14
O ‖ C
N
K 15
O ‖ C
N
S 16
O ‖ C
N
K 17
O ‖ C
N
L 18
O ‖ C
N
K 19
O ‖ C
N
K 20
O ‖ C
N
T 21
O ‖ C
N
E 22
O ‖ C
N
T 23
O ‖ C
N
Q 24
O ‖ C
N
E 25
O ‖ C
N
K 26
O ‖ C
N
N 27
O ‖ C
N
P 28
O ‖ C
N
L 29
O ‖ C
N
P 30
O ‖ C
N
S 31
O ‖ C
N
K 32
O ‖ C
N
E 33
O ‖ C
N
T 34
O ‖ C
N
I 35
O ‖ C
N
E 36
O ‖ C
N
Q 37
O ‖ C
N
E 38
O ‖ C
N
K 39
O ‖ C
N
Q 40
O ‖ C
N
A 41
O ‖ C
N
H
G 42
O ‖ C
N
E 43
O ‖ C
N
S 44
COOH
Ac
1

Ac

Position 1

Ser
2

Serine

Position 2

Asp
3

Aspartic Acid

Position 3

Lys
4

Lysine

Position 4

Pro
5

Proline

Position 5

Asp
6

Aspartic Acid

Position 6

Met
7

Methionine

Position 7

Ala
8

Alanine

Position 8

Glu
9

Glutamic Acid

Position 9

Ile
10

Isoleucine

Position 10

Glu
11

Glutamic Acid

Position 11

Lys
12

Lysine

Position 12

Phe
13

Phenylalanine

Position 13

Asp
14

Aspartic Acid

Position 14

Lys
15

Lysine

Position 15

Ser
16

Serine

Position 16

Lys
17

Lysine

Position 17

Leu
18

Leucine

Position 18

Lys
19

Lysine

Position 19

Lys
20

Lysine

Position 20

Thr
21

Threonine

Position 21

Glu
22

Glutamic Acid

Position 22

Thr
23

Threonine

Position 23

Gln
24

Glutamine

Position 24

Glu
25

Glutamic Acid

Position 25

Lys
26

Lysine

Position 26

Asn
27

Asparagine

Position 27

Pro
28

Proline

Position 28

Leu
29

Leucine

Position 29

Pro
30

Proline

Position 30

Ser
31

Serine

Position 31

Lys
32

Lysine

Position 32

Glu
33

Glutamic Acid

Position 33

Thr
34

Threonine

Position 34

Ile
35

Isoleucine

Position 35

Glu
36

Glutamic Acid

Position 36

Gln
37

Glutamine

Position 37

Glu
38

Glutamic Acid

Position 38

Lys
39

Lysine

Position 39

Gln
40

Glutamine

Position 40

Ala
41

Alanine

Position 41

Gly
42

Glycine

Position 42

Glu
43

Glutamic Acid

Position 43

Ser
44

Serine

Position 44

N-terminus C-terminus
Hydrophobic
Polar
Positive (+)
Negative (-)
Modified
Peak 0.0 mcg
Trough 0.0 mcg
SS Peak 0.0 mcg
SS Trough 0.0 mcg

Research Indications

Tissue Repair
Muscle Regeneration most effective

Accelerated healing of muscle fibers with reduced recovery time and enhanced repair via cell migration and differentiation.

Tendon & Ligament Healing most effective

Connective tissue repair with reduced scar formation and improved biomechanical properties of healing tissues.

Wound Healing most effective

Enhanced dermal closure, improved angiogenesis, and reduced inflammation in acute and chronic scenarios.

Athletic Recovery
Exercise Recovery effective

Faster recovery from intense training with reduced muscle soreness and improved tissue repair.

Injury Prevention effective

Strengthened tissues through enhanced repair mechanisms may reduce injury risk.

Performance Enhancement moderate

Improved muscle quality through enhanced regeneration and repair pathways.

Neurological
Neuroprotection moderate

Protective effects against neuronal damage in various models.

Spinal Cord Injury Support moderate

Preclinical evidence for improved outcomes in spinal injury models.

Brain Health emerging

Potential neuroprotective and regenerative effects on brain tissue.

Dosing Protocols

Subcutaneous or intramuscular injection. Flexible timing with no empty stomach requirement. Can be injected near injury site for localized effect.

GoalDoseFrequencyRoute
General tissue repair2-3mg2x weeklySubQ or IM
Serious injury recovery4-5mg3x weeklySubQ near injury site
Athletic enhancement2-3mg2x weeklySubQ
Chronic conditions3-4mg2-3x weeklySubQ or IM
Maintenance2mg1-2x weeklySubQ
Post-surgical recovery3-5mg3x weeklySubQ

Reconstitution Instructions

Materials Needed:
  • Bacteriostatic water (BAC)
  • Insulin syringes (1mL recommended)
  • Alcohol swabs
  • TB-500 vial (2mg or 5mg typical)
  • Sterile work surface
  1. 1 Clean work area and hands thoroughly with alcohol
  2. 2 Calculate required BAC water volume
  3. 3 Draw calculated BAC water slowly into syringe
  4. 4 Inject BAC water slowly down vial side (never directly on powder)
  5. 5 Gently swirl vial until powder completely dissolves
  6. 6 Store reconstituted solution refrigerated, use within 28 days

Interactions

++
BPC-157
Complementary healing mechanisms with enhanced tissue repair when combined (Wolverine Stack).
synergistic
+
Ipamorelin
May enhance tissue sensitivity to growth hormone effects.
compatible
++
CJC-1295
Combined tissue repair with GH-releasing effects for comprehensive recovery.
synergistic
++
IGF-1
Enhanced muscle and tissue regeneration through complementary growth pathways.
synergistic
+
GHRP-6
No negative interactions; potential enhanced recovery.
compatible
+
Melanotan II
Different receptor families with no pathway overlap.
compatible

What to Expect

Week 1-2
Reduced inflammation and improved tissue sensation
Week 2-4
Accelerated healing rate and improved tissue quality
Week 4-8
Maximum tissue repair and regenerative benefits
Week 6-12
Continued improvement in tissue strength and function

Side Effects & Safety

Common Side Effects

  • Generally minimal side effects
  • Possible mild injection site reactions
  • Temporary fatigue in some users

Stop Signs - Discontinue if:

  • Persistent or worsening injection site infections
  • Unusual swelling or prolonged redness
  • Severe allergic reactions
  • Unexpected systemic symptoms
  • Concerning health changes

Contraindications

  • Active cancer treatment (due to angiogenic effects)
  • Pregnancy or breastfeeding
  • Immunosuppressive medications (consult provider)
  • WADA prohibited for competitive athletes

Quality Checklist

Good Signs

  • White lyophilized powder - fine, evenly distributed with light fluffy texture
  • Clear, colorless solution after reconstitution with no particles
  • Proper vacuum seal intact with secure rubber stopper

Warning Signs

  • Slight powder clumping acceptable if completely dissolves with gentle swirling

Bad Signs

  • Colored or crystalline powder (yellow/brown indicates degradation)
  • Persistent cloudiness, floating particles, or precipitation
  • Damaged vial seal or contamination signs

References

  • The regenerative peptide thymosin beta-4 accelerates the rate of dermal healing in preclinical animal models and in patients
    Treadwell, T., Kleinman, H.K., Crockford, D., Hardy, M.A., Guarnera, G.T., Goldstein, A.L.
    Annals of the New York Academy of Sciences (2012)

    In two Phase 2 clinical trials, thymosin beta-4 accelerated healing of chronic pressure ulcers and venous stasis ulcers by almost a month compared to placebo, with confirmed safety and tolerability.

  • Development of thymosin beta4 for treatment of patients with ischemic heart disease
    Crockford, D.
    Annals of the New York Academy of Sciences (2007)

    Synthetic thymosin beta-4 given intravenously was well tolerated with no dose-limiting toxicity; promotes cardiomyocyte migration and survival, and stimulates coronary vasculogenesis for cardiac ischemia treatment.

  • Evaluation of skeletal and cardiac muscle function after chronic administration of thymosin beta-4 in the dystrophin deficient mouse
    Spurney, C.F., et al.
    PLoS One (2010)

    Chronic thymosin beta-4 administration increased the number of regenerating skeletal muscle fibers in exercised dystrophin-deficient (mdx) mice, showing potential for Duchenne muscular dystrophy treatment.

  • Thymosin beta-4 significantly improves signs and symptoms of severe dry eye in a phase 2 randomized trial
    Sosne, G., Dunn, S.P., Kim, C.
    Cornea (2015)

    Phase 2 randomized trial in 9 severe dry eye patients showed RGN-259 (0.1% thymosin beta-4) eye drops achieved statistically significant improvements in both signs and symptoms, with effects lasting 28 days post-treatment.

  • A first-in-human, randomized, double-blind, single- and multiple-dose, phase I study of recombinant human thymosin beta-4 in healthy Chinese volunteers
    Wang, X., et al.
    Journal of Cellular and Molecular Medicine (2021)

    Phase I study in 54 healthy subjects with ascending doses (0.05-25.0 mcg/kg) demonstrated mild to moderate adverse events with no dose-limiting toxicities or serious adverse events.

  • 0.1% RGN-259 (Thymosin beta-4) Ophthalmic Solution Promotes Healing and Improves Comfort in Neurotrophic Keratopathy Patients in a Randomized, Placebo-Controlled, Double-Masked Phase III Clinical Trial
    Sosne, G., Kleinman, H.K., Springs, C., Gross, R.H., Sung, J., Kang, S.
    International Journal of Molecular Sciences (2022)

    Phase III trial demonstrated thymosin beta-4 ophthalmic solution promotes corneal healing and improves comfort in neurotrophic keratopathy, advancing toward FDA approval.

Related Peptides

BPC-157 synergistic

Complementary healing mechanisms with enhanced tissue repair when combined (Wolverine Stack).

Ipamorelin compatible

May enhance tissue sensitivity to growth hormone effects.

GHRP-6 compatible

No negative interactions; potential enhanced recovery.

Melanotan II compatible

Different receptor families with no pathway overlap.

Disclaimer

This information is for educational and research purposes only. Consult a healthcare professional before use.