TB-500 / Thymosin Beta-4_
Also known as TB4, thymosin beta 4
A recovery peptide for healing muscle and tendon, often paired with BPC-157.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is TB-500 / Thymosin Beta-4?
Plain language first. The technical label stays, but it never stands alone.Overview
TB-500 is a synthetic fragment of thymosin beta-4, a natural protein involved in cell repair and movement. In plain terms: it is used to help muscles, tendons, and other tissue heal and to improve flexibility, though most evidence is from animals and most products are the fragment, not the full protein.
What it's used for
A recovery peptide used to heal muscles, tendons, and other injuries faster and move more freely. It is often paired with BPC-157.
How does TB-500 / Thymosin Beta-4 work?
What it does in the body, and where.TB-500 is a fragment of thymosin beta-4, a protein your body already uses when tissue needs repairing. Its main job is helping cells move.
- 01It binds actin, the protein cells use to moveRepair depends on the right cells physically reaching the damaged area, and that movement runs on actin.
- 02Repair cells migrate to the injuryMore cells arriving means faster closure of a wound and, in animals, better-organised tissue afterward.
- 03The figures usually quoted are for a different moleculeMost published healing numbers are for full thymosin beta-4, not the TB-500 fragment sold for injection, and are from animals.
Where this compound is thought to act.
What else is it used for?
Each group carries its own evidence level.Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.
Wound healing
Research only- Animal studyIn rats, new skin growth over a wound increased 42% by day four and up to 61% by day seven against saline.
- Animal studyWound contraction was about 11% greater by day seven.
- Lab studyIn lab dishes it stimulated skin-cell migration two to three fold, still active at 10 picograms.
Heart and eye
Research only- Animal studyIt was cardioprotective after a simulated heart attack in animals.
- Human trialTwo mid-stage human trials of the full-length protein applied to skin ulcers found it safe and reported faster healing.
- Human trialHuman eye-drop trials of the full-length protein reported improvement in dry eye and corneal damage.
Almost all the healing data, including the widely quoted 42% and 61% figures, comes from full-length Thymosin Beta-4, not the shorter TB-500 fragment sold online. They are different molecules and the results do not transfer directly.
How much, and do you cycle it?
The range, and whether you take breaks.2 up to 5 mg per week (start low, increase slowly), 1-2x per week. Commonly a loading period of 4 to 6 weeks, then less often, then stoppedCommunity practice
The loading-then-maintenance shape comes from community practice. No human study has tested a duration or a break.
How do I dose and price it?
Enter your vial and your dose. Pick a mix. We show the draw and the cost.The vial holds a fixed amount of drug. Adding more water does not make more drug, it just spreads it thinner, so you draw a bigger number on the syringe for the same dose.
Choose your mix
Measuring the water1 mL = one full 100-unit syringe.
Your draw
40 / 100 unitsHow do you store it?
Before mixing, and after.Dry powder in the freezer or fridge. Once mixed, fridge, and use within about a month.
Unmixed lyophilized TB-500 / Thymosin Beta-4 keeps for a long time cold. Once you add water the clock starts: most reconstituted vials hold up for roughly 28 to 30 days at fridge temperature. Keep it out of light, and do not freeze it after mixing.
What are the side effects and cautions?
Known cautions and warnings for this compound.22 July 2026Human trials of full-length thymosin beta-4 were run for wound and eye conditions and were generally well tolerated, but TB-500 as sold is a fragment, not the same molecule, and has no trial record of its own.
Who should avoid it
- Active cancer, as a precaution given the tissue-growth mechanism
- Pregnancy
- Banned in drug-tested sport
Stop and get help
- Signs of an allergic reaction
- New lumps or masses
Common effects
- Head rush or lightheadedness shortly after injecting
- Tiredness
- Injection-site reactions
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is TB-500 / Thymosin Beta-4 approved?
And where the numbers on this page come from.No. Not FDA-approved.
Human trials of full-length thymosin beta-4 were run for wound and eye conditions and were generally well tolerated, but TB-500 as sold is a fragment, not the same molecule, and has no trial record of its own.
- DoseFrom research and community reports. No regulator has reviewed this dose.
- Vial sizeFrom what vendors typically list; not a recommendation.
- Sources
- Reviewed22 July 2026
What else is like TB-500 / Thymosin Beta-4?
Others in Muscle building, side by side.If you're weighing TB-500 / Thymosin Beta-4, it's worth reading Bimagrumab, Ipamorelin + CJC-1295 blend, and IGF-1 LR3 in the same class.
A recovery peptide for healing muscle and tendon, often paired with BPC-157.
- Dose
- 2 up to 5 mg per week (start low, increase slowly)
- How often
- 1-2x per week
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- Dose
- 10 up to 30 mg/kg per month (trial doses)
- How often
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- Dose
- ~100 mcg CJC + 200-300 mcg ipa
- How often
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- Dose
- 0.02 up to 0.05 mg per day (start low, increase slowly)
- How often
- Daily, cycled
10What these words mean
Show glossary +
What these words mean
- Titrate
- Starting at a low dose and increasing it slowly over time so your body adjusts and side effects stay mild.
- Subcutaneous
- An injection just under the skin, into the fat layer, usually with a short, thin insulin needle.
- Intramuscular (IM)
- An injection into a muscle, using a longer needle.
- Reconstitution
- Mixing a powdered peptide with liquid (bacteriostatic water) so it can be drawn into a syringe.
- Bacteriostatic water
- Sterile water with a tiny amount of preservative, used to mix powdered peptides.
- Concentration
- How strong the mixed peptide is, in milligrams per milliliter (mg/mL). More water makes it weaker; less water makes it stronger.
- Units (on the syringe)
- The marks on an insulin syringe. 100 units equals 1 mL. They measure how much liquid you draw, not the dose in milligrams.
- mcg and mg
- Units of dose. 1 milligram (mg) equals 1,000 micrograms (mcg).
- GLP-1
- A natural gut hormone that lowers appetite and blood sugar. Drugs that copy it, like semaglutide, are used for weight loss.
- Growth hormone secretagogue
- A compound that nudges your body to release more of its own growth hormone, rather than injecting the hormone itself.
- Half-life
- How long a compound stays active in your body. A longer half-life means you inject less often.
- Peptide vs small molecule
- A peptide is a short chain of amino acids. A few items here (like MK-677 or methylene blue) are small molecules, not true peptides, but people use them the same way.
- Research only
- No approved dose or use in people. Sold for research and not reviewed by the FDA for safety or quality.
- Investigational
- Still being tested in clinical trials and not yet approved or legally sold for general use.
- Banned in drug-tested sport
- Prohibited by the World Anti-Doping Agency (WADA); using it can disqualify a competing athlete.
Sources
Last reviewed 22 July 2026