TB-500 / TB4
TB-500 (thymosin beta-4 fragment) is a 17-amino-acid synthetic peptide derived from the active region of thymosin beta-4. Studied in cellular-repair and angiogenesis research models.
We have not published an audit on TB-500 / TB4. Everything below is reference material, not our own reading of the literature, treat it as a starting point for questions, not as a grade.
How it is thought to work
Actin regulation; potential cell migration and repair signaling.
TB-500 is a small synthetic piece of a naturally occurring protein called thymosin beta-4; it keeps the part of that protein that binds to actin and may support tissue repair and new blood vessel formation, but most of the supporting research was done on the full-length protein, not this fragment.
Reported side effects
The most commonly reported effects in the research-use community are mild injection-site discomfort, redness, and brief fatigue or head-pressure in the first few days, while theoretical concerns include unwanted angiogenesis and immune modulation that have not been studied in humans.
Who should avoid it
People who are drug-tested athletes, pregnant or breastfeeding, have active or prior cancer, are allergic to peptide preparations or benzyl alcohol, have an infected injection site, or are seeking actual medical treatment for an injury or condition should avoid TB-500.
What gets monitored
Monitor injection site condition, sleep quality, cycle adherence, and any new or unusual symptoms. Baseline and end-of-cycle resting heart rate and blood pressure are suggested. [Source: Peptide Dosing Protocols]
What sources report
These are figures published elsewhere, reproduced with their source. Peppersite does not recommend an amount for TB-500 / TB4 or for anything else, and nothing below has been checked against the study it came from.
| Amount | Frequency | Route | Reported by |
|---|---|---|---|
| Standard: 2-2.5 mg subcutaneous twice weekly · Low: 2 mg twice weekly · High: 2.5 mg subcutaneous once weekly | twice weekly for loading, once weekly for maintenanceWeeks 1-6 for loading, Weeks 7-12 for maintenance · 4-12 weeks | subcutaneous injection | Peptide Dosing ProtocolsWhat it saysHide(secondary reference; provider confirmation required). TB-500 is commonly dosed at 2-2.5 mg subcutaneously twice weekly during the loading phase. |
| 2-2.5 mg SC twice weekly (loading 4-6 weeks), then 2 mg weekly maintenance | twice weekly (loading), then weekly4-6 week loading, then maintenance · Loading phase then maintenance phase | subcutaneous | Commonly published practitioner dosing range - provider confirmation required. |
| 2-2.5 mg per injection (loading); 750 mcg-2 mg (maintenance) | not stated | subcutaneous or oral or topical | Peptide Protocol WikiWhat it saysHide(secondary reference; provider confirmation required). |
| Referenced with a loading phase of 5-10 mg weekly for 4-6 weeks, then maintenance at 2-5 mg weekly split into smaller doses. Results typically noticed within 2-4 weeks. Caution flag: angiogenesis-promoting, so cancer or tumor history warrants medical consultation first. | Weekly total (2-10 mg) split into smaller doses · Post-workout or before bedOn-cycle 4-6 weeks, off-cycle 1-2 months | subcutaneous or intramuscular | Peptide Therapy Reference Text, internal KB v4What it saysHide(Aug 2026), secondary reference; provider confirmation required. |
- twice weekly for loading, once weekly for maintenanceWeeks 1-6 for loading, Weeks 7-12 for maintenance · 4-12 weeks
- subcutaneous injection
- Peptide Dosing Protocols
What it saysHide
(secondary reference; provider confirmation required). TB-500 is commonly dosed at 2-2.5 mg subcutaneously twice weekly during the loading phase.
- twice weekly (loading), then weekly4-6 week loading, then maintenance · Loading phase then maintenance phase
- subcutaneous
- Commonly published practitioner dosing range - provider confirmation required.
- not stated
- subcutaneous or oral or topical
- Peptide Protocol Wiki
What it saysHide
(secondary reference; provider confirmation required).
- Weekly total (2-10 mg) split into smaller doses · Post-workout or before bedOn-cycle 4-6 weeks, off-cycle 1-2 months
- subcutaneous or intramuscular
- Peptide Therapy Reference Text, internal KB v4
What it saysHide
(Aug 2026), secondary reference; provider confirmation required.
- 2.0 mL bacteriostatic water for 10 mg vial
- Commonly 5 mg or 10 mg vials · Reconstitute with bacteriostatic water
- Bacteriostatic water
Common questions
What is TB-500?
TB-500 is a synthetic 7-amino-acid fragment of thymosin beta-4, a larger peptide found throughout the body.
Is TB-500 the same as thymosin beta-4?
No, TB-500 is a 7-amino-acid synthetic fragment of the 43-amino-acid full-length thymosin beta-4.
What is TB-500 commonly researched for?
TB-500 is most often referenced in research-use contexts focused on actin-mediated cell migration and tissue repair signaling.
What is a typical TB-500 dosing pattern in research planning?
Community-referenced research planning frequently uses about 2 to 2.5 mg subcutaneous twice weekly during a 4-6 week loading phase.
How is TB-500 reconstituted?
Most planners reconstitute a 10 mg vial with 2.0 mL of bacteriostatic water, which gives 5 mg/mL.
Check 10 mg in 2 mL in the calculator →How long is a typical TB-500 cycle?
Common research-use cycles run 4-12 weeks, typically with a 4-6 week loading phase followed by maintenance.
Can BPC-157 and TB-500 be used together?
Yes, the BPC-157 + TB-500 combination is commonly paired in the research-use community.
Is TB-500 FDA-approved?
No, TB-500 is not approved by the FDA for any human use.
Sources
The reference sections above are imported from our compound knowledge base, which classes the evidence for TB-500 / TB4 as emerging. That classification is the knowledge base’s, not ours, our own grade appears only where an audit is linked above. Research use only; nothing here is medical advice or a protocol.
BPC-157 is a synthetic pentadecapeptide derived from a protective protein found in gastric juice. Studied in tissue-repair and regeneration research models.
Peptide blend of GHK-Cu, BPC-157, and TB-500, studied for skin quality, tissue repair, and recovery.
5-Amino-1MQ is a small molecule studied for its potential to help the body shrink fat cells and raise NAD+ levels without cutting appetite.
Peptide bioregulator referenced for connective tissue support.
Peptide bioregulator referenced for nervous system support.
Combination research blend of CJC-1295 (no DAC) and Ipamorelin. Studied as a GHRH/GHRP combination in growth-hormone-axis research.