TB-500
A synthetic peptide related to thymosin beta-4, a natural protein involved in cell movement and wound repair. Human data on TB-500 itself is essentially absent.
- more wound re-covering in rats at day 4 vs saline (thymosin beta-4)
- +42%
- amino acids in natural thymosin beta-4
- 43
- no human exposure data identified by the FDA
- Not approved
more wound re-covering in rats at day 4 vs saline (thymosin beta-4)[1]
amino acids in natural thymosin beta-4
no human exposure data identified by the FDA[2]
3 sources, every claim linked. PepDose sells no peptides and takes no vendor money.
01 · What it is
What is TB-500?
Thymosin beta-4 is a small protein made naturally by many cell types, including platelets. TB-500 is the name used for synthetic versions sold as research products, usually a full or partial copy of thymosin beta-4.
It is not approved as a medicine. Most of the research is on thymosin beta-4, not on the specific products sold as TB-500.
Illustration.
Thymosin beta-4
- Natural protein, 43 amino acids
- Made by many cell types, including platelets
- What the research studied
TB-500
- Synthetic product name
- Full sequence or a short fragment: varies by seller
- Not itself studied in people
02 · How it works
How does TB-500 work?
Thymosin beta-4 binds actin, a protein cells use to move. After an injury it helps cells migrate into the damaged area, supports new blood vessel growth, and lowers inflammation and scarring in lab and animal studies.
03 · Research
What does the research on TB-500 show?
The research is on thymosin beta-4, the natural protein TB-500 is based on, and it is almost all in animals and cells. In rats with skin wounds, thymosin beta-4 increased wound re-covering by 42% at day 4 and up to 61% at day 7 compared with saline. Human data on TB-500 itself is essentially absent.
Wound healing in rats: saline vs thymosin beta-4
Measured: 42% more wound re-covering at day 4 and up to 61% more at day 7 than saline.[1]
The animation is an illustration of cells moving in from the edges, not the measured wound sizes. This was a rat study of thymosin beta-4, not of TB-500 products.
- In rats with full-thickness skin wounds, thymosin beta-4 increased wound re-covering by 42% at day 4 and up to 61% at day 7 compared with saline.[1]
- Reviews describe its studied roles in skin, eye, heart and brain repair, with clinical trials planned or running for skin wounds and corneal injuries.[3]
04 · Side effects
What are the side effects of TB-500?
The side effects of TB-500 in people are not known. The FDA says it identified no human exposure data for thymosin beta-4 or TB-500 in compounding, and it flagged a risk of immune reactions. Because products are unregulated, the purity and the actual amount in a vial are also unknown.
Commonly listed reasons to avoid it
- Pregnancy and breastfeeding
- Active cancer or a history of cancer
Not approved
05 · Legal and regulatory status
Is TB-500 FDA-approved?
No. TB-500 is not FDA-approved. Thymosin beta-4/TB-500 was on the FDA's list of compounding substances that may present significant safety risks; as of April 2026 that listing shows as withdrawn. An FDA advisory committee discussed TB-500 for compounding in July 2026.
- Not FDA-approved. Thymosin beta-4/TB-500 was on the FDA's list of compounding substances that may present significant safety risks; as of April 2026 that listing shows as withdrawn. An FDA advisory committee discussed TB-500 for compounding in July 2026.[2]
06 · Mixing and units
How do you mix TB-500 and read the units?
Units on a U-100 syringe = dose (mg) ÷ concentration (mg/mL) × 100. For example, a 5 mg vial mixed with 2 mL of bacteriostatic water is 2.5 mg/mL, so 10 units hold 0.25 mg. Pick your vial and water below; the maths is the same for any brand of TB-500.
- 1 Peptide vial
- 2 Bacteriostatic water
- 3 U-100 syringe
- 4 Alcohol swabs
Vial size
Water added
- TB-500 in the vial
- 5 mg
- Water added
- 2 mL
- Strength
- 2.5 mg/mL
- 1 unit holds
- 25 mcg
- Step 1
Clean
Wipe the vial stopper with an alcohol swab and let it dry.
- Step 2
Add water
Let the bacteriostatic water run slowly down the inside wall of the vial.
- Step 3
Swirl
Swirl or roll gently until clear. Don't shake.
- Step 4
Label and chill
Write the date and strength (mg/mL) on the vial and keep it in the fridge.
The full TB-500 protocol
- Week-by-week schedule and titration
- What to track and when
- Stacking notes and timing
- Dose tracker with injection-site rotation
- Every study explained in detail
- Step-by-step start guide
07 · Questions
Common questions about TB-500
How much BAC water for TB-500 10 mg?
With 2 mL the vial is 5 mg/mL, so 10 units holds 0.5 mg and 50 units holds 2.5 mg. With 1 mL it is twice as strong per unit.
Is TB-500 the same as thymosin beta-4?
Closely related. Thymosin beta-4 is the natural 43-amino-acid protein that the research is about. Products sold as TB-500 are synthetic and vary; some are the full sequence and some are a short fragment. Check what your label says.
BPC-157 vs TB-500?
Both are studied mainly in animals for healing. BPC-157 is a gastric-protein fragment; TB-500 is related to thymosin beta-4, which helps cells migrate. They are often sold together in blends.
What does TB-500 do?
TB-500 is related to thymosin beta-4, which binds actin, a protein cells use to move. In lab and animal studies thymosin beta-4 helped cells migrate into damaged tissue, supported new blood vessel growth, and lowered inflammation and scarring.
Is TB-500 FDA-approved?
No. It is not an approved medicine. Thymosin beta-4/TB-500 was on the FDA's compounding safety-risk list; as of April 2026 that listing shows as withdrawn, and an FDA advisory committee discussed it in July 2026.
What are the side effects of TB-500?
They are not known in people. The FDA identified no human exposure data for thymosin beta-4/TB-500 in compounding and flagged a risk of immune reactions. Purity and the real amount in an unregulated vial are also unknown.
Sources
- 1.Thymosin beta4 accelerates wound healing
Malinda KM et al. J Invest Dermatol 1999;113:364-368 · Animal study - 2.FDA compounding safety-risk list
FDA. Bulk drug substances for compounding that may present significant safety risks (as of Apr 22, 2026) · FDA - 3.Thymosin β4: a multi-functional regenerative peptide
Goldstein AL et al. Expert Opin Biol Ther 2012;12:37-51 · Review