Peptide Guide + Calculator
TB-500 Reconstitution Calculator & Guide
Thymosin Beta-4 Fragment
TB-500 is a synthetic peptide fragment derived from the actin-binding region of thymosin beta-4 and is widely discussed in injury-recovery, mobility, and performance communities. Human evidence for TB-500 itself is extremely limited, and FDA has stated that it has not identified human exposure data or clinical studies using TB-500. This page explains the difference between TB-500 and full-length thymosin beta-4, current evidence and safety limitations, anti-doping status, comparisons with BPC-157, and educational reconstitution math.
Evidence Snapshot
TB-500 research at a glance
Standardized regulatory and evidence context so research compounds, investigational drugs, and approved medications are not treated as if they have the same level of human evidence.
Regulatory status
Not FDA-approvedDevelopment / evidence stage
Preclinical / no established human program
No established development program
Human evidence level
No meaningful direct human therapeutic evidencePrimary mechanism
Synthetic Ac-LKKTETQ fragment associated with the actin-binding region of thymosin beta-4.
WADA context
Explicitly prohibited — S2Primary targets
Human intervention evidence
FDA reported that it had not identified human exposure data or clinical studies using TB-500 itself. Human studies of full-length thymosin beta-4 should not be treated as TB-500 evidence.
Human biology evidence
Many mechanistic claims are extrapolated from full-length thymosin beta-4 biology rather than TB-500 itself.
Key takeaway
TB-500 should not inherit the evidence base of full-length thymosin beta-4; direct human evidence for the fragment is exceptionally thin.
Evidence labels describe the research base and regulatory context; they are not treatment, dosing, or use recommendations. Review dates describe the last BACToBasics source check for this evidence summary. Anti-doping rules can change and should be verified with the applicable authority.
TB-500 Reconstitution Calculator
Enter the vial amount, liquid volume, and amount you want to calculate. BACToBasics will automatically calculate concentration, liquid volume, and U-100 syringe-unit equivalents.
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Calculator values are educational math inputs only. They are not recommended preparation amounts, doses, or use protocols.
TB-500 Reconstitution Math
Reconstitution math starts with the amount contained in the vial and the liquid volume used in the calculation. Dividing the vial amount by the liquid volume gives the resulting concentration.
Example vial amount
5 mg
| Liquid Volume | Calculation | Concentration |
|---|---|---|
| 1 mL | 5 mg ÷ 1 mL | 5 mg/mL |
| 2 mL | 5 mg ÷ 2 mL | 2.5 mg/mL |
| 3 mL | 5 mg ÷ 3 mL | 1.6667 mg/mL |
This table demonstrates concentration math only. The liquid volumes shown are examples for comparison and are not preparation recommendations.
More Reconstitution Tools
Need to compare different liquid volumes or convert between mg, mcg, mL, and U-100 units? Use the dedicated BACToBasics calculator tools.
What is TB-500?
TB-500 is commonly used as the name for the N-acetylated heptapeptide N-acetyl-LKKTETQ, a fragment associated with the actin-binding region of the naturally occurring peptide thymosin beta-4. It is marketed online for recovery and tissue-repair purposes, but it is not an FDA-approved medication and should not be assumed to have the same evidence base as full-length thymosin beta-4.
TB-500 vs thymosin beta-4
TB-500 and thymosin beta-4 are related but are not the same substance. Full-length thymosin beta-4 is a naturally occurring 43-amino-acid peptide with research involving cell migration, inflammation, angiogenesis, and wound repair. TB-500 is a much smaller synthetic fragment derived from a region of thymosin beta-4. Findings from full-length thymosin beta-4 studies cannot automatically be attributed to TB-500.
What does the research on TB-500 actually show?
The evidence specifically for TB-500 is far thinner than online discussions often suggest. In its 2026 review, FDA reported that it had not identified clinical studies or human exposure data using TB-500 by any route. FDA also reported that it did not identify published nonclinical in-vivo studies evaluating TB-500 for wound-related effects. This means many recovery claims are extrapolated from thymosin beta-4 research, laboratory work, animal-related literature, or anecdotal use rather than direct human TB-500 trials.
What has been studied with full-length thymosin beta-4?
Full-length thymosin beta-4 has a separate research history that includes preclinical tissue-repair studies and human trials using topical formulations for chronic wounds. For example, a randomized Phase 2 study in people with venous stasis ulcers evaluated topical thymosin beta-4 and reported an acceptable safety profile with signals suggesting faster wound healing at one studied concentration. These findings involve full-length thymosin beta-4 applied topically and should not be treated as clinical evidence for injected TB-500.
TB-500 for tendon, ligament, and muscle recovery
Tendon, ligament, muscle, and soft-tissue recovery are among the most common reasons TB-500 is discussed online. However, FDA's 2026 review did not identify human clinical studies establishing that TB-500 improves these outcomes. Claims about injury recovery therefore remain unproven in humans and should be distinguished from mechanistic or preclinical research involving full-length thymosin beta-4.
TB-500 and wound-healing claims
TB-500 is frequently marketed around wound healing because it is derived from a region of thymosin beta-4 associated with actin binding. That biological relationship does not establish that the fragment reproduces the clinical effects of full-length thymosin beta-4. FDA's 2026 review noted a lack of published in-vivo wound studies for TB-500 itself and no identified human exposure data.
TB-500 vs BPC-157
TB-500 and BPC-157 are often discussed together in recovery communities, but neither has an established FDA-approved injury-recovery indication. BPC-157 has a larger preclinical literature involving several tissue types, while the evidence specifically for TB-500 is especially sparse. FDA has raised safety and evidence concerns about compounded products containing both substances, and online stack discussions should not be interpreted as proof that combining them is safe or effective.
What is known about TB-500 safety?
The human safety profile of TB-500 is not established. FDA has stated that it has not identified human exposure data for TB-500 and therefore lacks important information needed to determine whether it would cause harm when administered to humans. FDA has also identified potential concerns involving immunogenicity, aggregation, peptide-related impurities, and active-ingredient characterization.
Is TB-500 FDA-approved?
No. TB-500 is not an FDA-approved drug. FDA lists thymosin beta-4 fragment (LKKTETQ), also known as TB-500, among bulk drug substances that may present significant safety risks when used in compounding because important human safety information is lacking.
Is TB-500 banned in competitive sports?
Yes. The World Anti-Doping Agency's 2026 Prohibited List includes thymosin beta-4 and its derivatives, including TB-500, under the growth-factor and growth-factor-modulator section. It is prohibited at all times for athletes subject to WADA rules.
Research TB-500 vs an approved medication
Products sold online as research TB-500 are not FDA-approved pharmaceutical products. Their identity, purity, concentration, sterility, storage conditions, and manufacturing quality should not be assumed from a label alone. There is also no FDA-approved TB-500 product with an established clinical dosing regimen for injury recovery or performance purposes.
TB-500 reconstitution math
Reconstitution calculations depend on the labeled amount in a vial and the liquid volume used. As a mathematical example, a 5mg vial combined with 2mL of liquid produces a concentration of 2.5mg per mL, or 2,500mcg per mL. BACToBasics uses examples like this only to demonstrate concentration, liquid-volume, and U-100 syringe-unit calculations rather than to recommend a preparation or dosing protocol.
Explore more about TB-500
15 linksComparisons, research records, development tracking, blends, and related guides are available here when you want to go deeper.
Explore more about TB-500
15 linksComparisons, research records, development tracking, blends, and related guides are available here when you want to go deeper.
Compare TB-500
Direct comparison pages are selected from the indexable BACToBasics comparison catalog and update automatically as that catalog grows.
Research, updates & development
Jump from the guide into the public update timeline, compound-specific research records, and clinical-development tracker without searching again.
TB-500 research & development updates
Open the public timeline of sourced research records and material development changes tracked by BACToBasics.
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ResearchTB-500 research sources
Open 1 curated research record for TB-500.
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DevelopmentTB-500 clinical development
Preclinical / no established human program · No established development program. No established direct human therapeutic development milestone for TB-500 itself.
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Blend guides containing TB-500
These pages are derived from blend component metadata, so a new blend automatically becomes discoverable from each linked component guide.
Related peptide guides
Related guides are ranked from shared comparison pages, shared blend pages, and peptide category rather than a hand-maintained link list.
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Relevant glossary concepts
Definitions are matched against the guide's structured title, subtitle, description, and educational sections.
FDA-Approved
A status indicating that the FDA has approved a specific drug product for one or more labeled uses after reviewing the required evidence and manufacturing information.
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GlossaryMilliliter (mL)
A metric unit of liquid volume equal to one-thousandth of a liter.
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GlossaryConcentration
The amount of a substance contained in a given volume of liquid, such as mg/mL or mcg/mL.
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TB-500 FAQ
Tap a question to expand only the answer you want to read.
Is TB-500 FDA-approved?
No. TB-500 is not an FDA-approved medication. FDA has specifically identified the thymosin beta-4 fragment known as TB-500 as a substance for which important human safety information is lacking.
Is TB-500 the same as thymosin beta-4?
No. TB-500 is a synthetic fragment derived from a region of thymosin beta-4. Full-length thymosin beta-4 contains 43 amino acids and has a different research history. Results from full-length thymosin beta-4 studies cannot automatically be applied to TB-500.
Are there human clinical trials of TB-500?
FDA reported in its 2026 review that it had not identified clinical studies or human exposure data using TB-500 by any route. Human evidence for TB-500 itself therefore remains extremely limited.
Does TB-500 heal tendons or ligaments?
TB-500 is widely discussed for tendon and ligament recovery, but controlled human clinical evidence establishing that TB-500 heals these injuries is lacking. Claims are often extrapolated from thymosin beta-4 biology rather than direct TB-500 trials.
Does TB-500 help muscle recovery?
Muscle and soft-tissue recovery are common online claims, but FDA has not identified human clinical studies demonstrating that TB-500 improves muscle recovery or injury healing.
What are the side effects of TB-500?
There is not enough human evidence to define a reliable TB-500 side-effect profile or estimate how frequently adverse effects occur. FDA has highlighted the absence of human exposure data and potential concerns involving immune reactions, aggregation, peptide impurities, and product characterization.
Why do people combine TB-500 with BPC-157?
Both substances are commonly discussed in online recovery communities, which is why they are often marketed or described together. There is not high-quality human evidence establishing that combining TB-500 and BPC-157 is safe or more effective than either substance alone.
Is TB-500 banned by WADA?
Yes. WADA's 2026 Prohibited List includes thymosin beta-4 and its derivatives, including TB-500, among prohibited growth factors and growth-factor modulators. It is prohibited at all times for athletes covered by WADA rules.
Is TB-500 measured in mg or mcg?
Products labeled as TB-500 are commonly described in milligrams at the vial level, while smaller mathematical quantities may be expressed in micrograms. One milligram equals 1,000 micrograms.
How do you calculate TB-500 reconstitution concentration?
Divide the labeled vial amount by the liquid volume. For example, 5mg divided by 2mL equals 2.5mg per mL, which is also 2,500mcg per mL. This is concentration math rather than a recommendation for how a product should be prepared.
Can the BACToBasics calculator handle TB-500 math?
Yes. Enter a labeled vial amount and liquid volume to calculate concentration, equivalent liquid volume, U-100 syringe units, and approximate amounts per vial. BACToBasics provides educational math rather than dosing advice.
Sources & References
5 sourcesOpen the references when you want to inspect the research and regulatory sources behind this guide.
Sources & References
5 sourcesOpen the references when you want to inspect the research and regulatory sources behind this guide.
FDA states that compounded products containing the thymosin beta-4 fragment known as TB-500 may pose immunogenicity and impurity-related risks and that FDA has not identified human exposure data for TB-500.
FDA's 2026 review reports no identified clinical studies or human exposure data using TB-500 and no identified published nonclinical in-vivo wound studies for TB-500 itself.
The 2026 list includes thymosin beta-4 and its derivatives, including TB-500, under prohibited growth factors and growth-factor modulators.
WADA research describing TB-500 as the N-terminal acetylated 17-23 fragment of thymosin beta-4 (Ac-LKKTETQ) and examining anti-doping detection methods.
Human Phase 2 study of topical full-length thymosin beta-4 in venous stasis ulcers. This study is included to distinguish the clinical evidence for full-length thymosin beta-4 from the much thinner evidence for TB-500. PMID: 20536470.
BACToBasics provides educational information and math tools only. This content is not medical advice, dosing advice, injection instruction, or a recommendation to use any peptide or medication.