TB-500 Peptide: What the Research Shows

Quick facts

What is in it

One lab-made peptide sold as a short fragment of a natural protein called thymosin beta-4. It is not a blend.

One molecule, not a blend. TB-500 is one of the peptides sold together in blends such as KLOW and GLOW. The studies below are about the fragment or the full protein tested on its own, not about any blend, and the difference between the two forms matters, see the gaps below.

Studied for

Wound and tissue repair. Human trials tested the full-length thymosin beta-4 protein for leg ulcers, for dry eye discomfort as eye drops, and after a heart attack. Animal studies looked at skin wound healing and protection after heart injury. No human trial found tested the actual short fragment sold as TB-500.

Human evidence, part by part

TB-500 (thymosin beta-4 fragment)Limited2 human studies found

Approved by the FDA?

Not an FDA-approved drug. The fragment sold as TB-500 appears on FDA's list of bulk drug substances that were nominated for compounding use and then withdrawn. See where it stands.

Benefits

Evidence Eased discomfort and surface damage in severe dry eye, in a 9-person trial of eye drops. PMID 25826322
Evidence Was about as safe as placebo, and a minority of patients healed fully, in a 73-person leg-ulcer trial. PMID 20536470
Evidence Showed less heart damage after injury in mouse studies of the full parent protein. PMID 27450736
Evidence Animal studies suggested faster skin wound healing and less inflammation with the full parent protein. PMID 27450738
Suggested Discussed for wound and tissue repair, based mainly on the full-length protein rather than the sold fragment.
Suggested Promoted as BPC-157's healing partner in the 'Wolverine' stack, a pairing never tested together.
Suggested Discussed by online clinician commentary as aiding cell migration, complementing BPC-157's blood-vessel effects.

Evidence items link to the study behind them. Suggested items are claims in circulation, not results.

Reported side effects

No human trial has tested the actual short fragment sold as TB-500; all human studies used the full protein.
Was about as safe as placebo in a 73-person leg-ulcer trial of the full protein. PMID 20536470
Eye drops made from the full protein were safe and well tolerated over 56 days in a 9-person trial. PMID 25826322
FDA states it has found no human exposure data for the TB-500 fragment given by any route.
Is on FDA's list of bulk substances nominated for compounding, then withdrawn over safety concerns.

Safety, before anything else

No human trial has tested the actual fragment sold as TB-500. Every human study behind this page used the full-length thymosin beta-4 protein, a different and larger molecule. TB-500 is not an FDA-approved drug and is on FDA's list of bulk substances nominated for compounding and then withdrawn, listed there as Thymosin Beta-4, Fragment.

TB-500 (thymosin beta-4 fragment)

Safety comparable to placebo in a 73-person trial of the full protein. PMID 20536470
We found no human study of the shorter TB-500 fragment that is actually sold.
Eye drops safe and well tolerated over 56 days in a 9-person trial. PMID 25826322

We do not publish amounts or schedules of our own, on any page. The clinician commentary lower on this page quotes amounts that named clinicians state on camera, labeled and linked to the source video. Those are their words, not our guidance. Why we draw that line.

How to read the grades

Each study gets a tag. Cells in a dish means it never touched a living animal. Animals means mice or rats, usually. Small human study means a handful of people with no comparison group. Human trial means people were randomly split into treated and untreated groups, which is the only kind that can show an effect is real. Review and Systematic review sum up other studies. The full rule is on How we check.

TB-500 (thymosin beta-4 fragment)

Thymosin beta-4 is a natural protein in almost every cell that helps cells move and rebuild. TB-500 is the name used for a lab-made piece of it. Most studies used the full protein, not the fragment.

Human evidence: Limited. 2 human studies found in our search.

What has been studied

Who or what was studied	What was found, and the catch	Source
Human trial n = 73 people	In people with leg ulcers, thymosin beta-4 was as safe as placebo and a minority of treated patients healed fully. Limit: One mid-stage trial; benefit over placebo was modest.	Guarnera 2010 PMID 20536470
Review	Summarizes thymosin beta-4's role in cell movement and tissue repair and lists trials then under way. Limit: Author helped develop the compound.	Goldstein 2012 PMID 22074294
Review	Animal studies suggest faster skin wound healing and less inflammation. Limit: Large controlled human trials for skin wounds are missing.	Kleinman 2016 PMID 27450738
Review	Animal studies suggest less heart damage after injury. Limit: No human heart outcome trials cited.	Pipes 2016 PMID 27450736
Review	Explains how thymosin beta-4 binds actin, the cell's scaffolding protein. Limit: Structure only, not a treatment study.	Bubb 2003 PMID 12852258
Human trial n = 9 people	Thymosin beta-4 eye drops eased discomfort and surface damage in severe dry eye versus placebo. Limit: Nine people, eye drops, many comparisons.	Sosne 2015 PMID 25826322
Human trial n = 96 people	In a 96-patient heart-attack trial, the main result was not statistically significant; a timing subgroup showed smaller infarcts. Mice showed less heart damage. Limit: Used the full recombinant protein, not the TB-500 fragment sold.	Zhang 2025 PMID 41229390
Review	How thymosin beta-4 was found as the cell's main actin-binding peptide. Limit: Basic science, not treatment.	Hannappel 2007 PMID 17468232

Safety signals in the studies

Safety comparable to placebo in a 73-person trial of the full protein. PMID 20536470
We found no human study of the shorter TB-500 fragment that is actually sold.
Eye drops safe and well tolerated over 56 days in a 9-person trial. PMID 25826322

Where it stands with regulators

The TB-500 fragment appears on FDA's list of bulk drug substances nominated for compounding and then withdrawn, listed there under the name Thymosin Beta-4, Fragment (LKKTETQ), under the heading Bulk drug substances nominated but withdrawn. FDA's stated concern: possible immune reactions from aggregation and peptide related impurities, and FDA states it has not identified any human exposure data for products containing this fragment. Page content current as of 04/22/2026, checked 08-26-2026. Source

What is missing

No human study has tested the fragment actually sold as TB-500. Every human trial used the full-length thymosin beta-4 protein instead, in leg ulcers, dry eye drops, and one heart attack trial whose main result did not reach statistical significance. Whether results from the full protein say anything about the smaller fragment sold to consumers has not been tested.

Clinician commentary (YouTube)

This is commentary, not evidence. 3 clinicians with large audiences discuss this on camera. Each video below is summarized in our words and linked so you can watch the source yourself. Any amounts mentioned are what the named clinician says on camera, not PeptideGauge guidance. The graded studies above remain the record of what is known. How this layer works.

Dr. Alex Tatem

In “BPC-157 & TB-500: The Truth About the Wolverine Stack”, Dr. Alex Tatem discusses TB-500. What he says, in short:

He describes TB-500 as a synthetic 7 amino acid fragment of thymosin beta 4, a 43 amino acid protein discovered in the 1960s, that works mainly by regulating actin to help cells migrate to injury sites.
He states plainly there are zero published human clinical trials for TB-500 itself.
He says the parent protein thymosin beta 4 has better data: a 0.1% eye drop version showed a 35% reduction in ocular discomfort and 59% reduction in corneal staining in a phase 2 trial for severe dry eye, and a trial in 96 heart attack patients showed reduced infarct size in a subgroup at 90 days though the overall group result was not statistically significant.
He cites a 2024 study suggesting TB-500's wound healing activity may actually come from its breakdown product AC-LK rather than TB-500 itself.
He says anecdotal side effects include headaches, injection site swelling, nausea with oral use, and hot flashes from vasodilation, and that rat metabolism data showed no cytotoxicity.

Link checked 08-26-2026. The summary is our paraphrase; the claims are Dr. Alex Tatem’s, not ours.

In “It’s Official: 7 Life-Changing Peptides are BACK.”, Dr. Alex Tatem discusses TB-500. What he says, in short:

He calls TB-500 the other half of the Wolverine stack alongside BPC-157, grouping it with the tissue repair and regeneration peptides.
He explains TB-500 is a synthetic fragment of thymosin beta-4, a peptide the body already produces, which under the Myriad Genetics precedent means it cannot be patented as a new composition of matter, removing the economic case for a formal drug trial.
He says TB-500 was among the 19 peptides swept from category 1 into prohibited category 2 by the FDA's September 2023 website update, done without public notice.
He notes TB-500 is one of seven peptides going before the Pharmacy Compounding Advisory Committee, scheduled for day one of the July 23 to 24, 2026 hearing alongside BPC-157, KPV and MOTS-c.
He reiterates that a favorable PCAC recommendation would restore compounding eligibility under enforcement discretion, not FDA approval, and that the formal rulemaking process afterward could take roughly 12 to 24 months.

Link checked 08-26-2026. The summary is our paraphrase; the claims are Dr. Alex Tatem’s, not ours.

1 more video where Dr. Alex Tatem covers TB-500

In “Every Popular Peptide Ranked | GLP-1, Growth Hormone, HCG, NAD+, IGF-1, Peptide Tier List”, Dr. Alex Tatem discusses TB-500. What he says, in short:

He describes TB-500 as derived from thymosin beta 4, working through actin and cytoskeleton mechanisms to drive cell migration, a different mechanism from BPC-157's effect on fibroblasts, which is why the two are combined as the Wolverine stack.
He says there is no human data on TB-500 itself, though the precursor thymosin beta 4 shows benefit as a topical eye drop for corneal abrasions and dry eye, a very different application.
He says reports are split about half positive and half 'did nothing,' gray market sourcing means purity is unknown, and no adverse safety signals have shown up so far, giving it a C tier ranking alongside BPC-157.

Link checked 08-26-2026. The summary is our paraphrase; the claims are Dr. Alex Tatem’s, not ours.

Dr. Ashley Froese

In “Dr Admits - I Was WRONG About The Wolverine Stack”, Dr. Ashley Froese discusses TB-500. What she says, in short:

She says TB 500 comes from a natural protein, thymosin beta 4, discovered in the 1980s when researchers noticed it showing up at every site of tissue injury.
She explains its main mechanism as binding to actin, the cell's internal skeleton, which helps repair cells physically migrate to the site of injury, likening it to improving the roads to the construction site.
She says TB 500 is larger and more fragile than BPC 157, about 5,000 daltons versus 1,400 daltons, so oral delivery likely does not reach meaningful systemic levels, and she personally questions any delivery method for it besides injection.
She says it circulates systemically in response to inflammatory signals rather than needing to be delivered at the injury site.

Link checked 08-26-2026. The summary is our paraphrase; the claims are Dr. Ashley Froese’s, not ours.

In “KLOW - Dr Explains The Peptide Stack For Healing, Inflammation and Regeneration”, Dr. Ashley Froese discusses TB-500. What she says, in short:

She describes TB-500 as a thymosin beta fragment that acts like a cellular foreman by controlling actin sequestering.
She says actin works like scaffolding for cell repair, and TB-500 stockpiles and releases it to help healing cells migrate faster and to stimulate new blood vessel formation.
She pairs it with BPC-157 in the Wolverine stack, saying it drives new blood vessel growth from a different entry point than BPC-157 does.

Link checked 08-26-2026. The summary is our paraphrase; the claims are Dr. Ashley Froese’s, not ours.

1 more video where Dr. Ashley Froese covers TB-500

In “The FDA Is About to Decide the Future of Peptides: BPC-157, TB-500, KPV, & MOTS-C”, Dr. Ashley Froese discusses TB-500. What she says, in short:

She says the FDA is reviewing it specifically for wound healing.
She describes it as regulating actin, calling it a cellular construction foreman that directs cells to migrate to an injury site to rebuild tissue.
She says people use it for healing injuries, joint pain, strains, and sprains, the same as BPC-157.
She says once you understand the science of both, it is hard to argue against using the combination.

Link checked 08-26-2026. The summary is our paraphrase; the claims are Dr. Ashley Froese’s, not ours.

Dr. Jones, DC

In “What Science ACTUALLY Says About BPC-157 Benefits, Dosing & Side Effects (Doctor Reveals Truth)”, Dr. Jones, DC discusses TB-500. What he says, in short:

He describes TB-500 as doing a completely different job from BPC-157, moving repair cells to the injury rather than building the blood supply.
He says the two are used together because they act on different pathways, while admitting there are no studies comparing one against the other.
He describes a clinic range working up to 2,000 micrograms daily for acute injuries, and says chronic cases over six months start with TB-500 alone at 2,000 micrograms for two weeks before BPC-157 is added.
He describes a post-surgical sequence in which TB-500 is added at 1,000 micrograms daily from week three onward and increased as tolerated.
He says Achilles injuries in particular must have high dose TB-500 in his experience.
He recounts a marathoner with bilateral Achilles tendinopathy who saw minimal improvement on BPC-157 alone and improved after TB-500 was added at 2,000 micrograms daily, which he presents as a clinic anecdote rather than published evidence.
He says reconstituted vials last 30 to 45 days kept cold and out of light, and that a cloudy bottle should be thrown out rather than injected.

TB500 helps your repair cells get there faster.

Link checked 08-26-2026. The summary is our paraphrase; the claims are Dr. Jones, DC’s, not ours. Quoted lines are taken from the automatic captions on the video, so the wording can differ slightly from the audio.

In “Doctor Reacts to Most Powerful Peptide Stacks (GLOW, KLOW & Wolverine)”, Dr. Jones, DC discusses TB-500. What he says, in short:

He describes TB-500 as a fragment of thymosin beta 4 with anti-inflammatory properties that promotes tissue regeneration.
He says it helps the body rebuild tissue after a tendon tear, ligament sprain, or muscle damage.
He says it also improves flexibility and reduces scar tissue formation.
He describes about 500 micrograms daily inside the GLOW protocol and 2 milligrams daily in the aggressive Wolverine protocol he says he ran on himself.
He presents duration as the variable people get wrong, saying he ran it daily for three full months rather than two weeks or a month.

Now, TB500 is actually a fragment of thyos and beta 4.

4 more videos where Dr. Jones, DC covers TB-500

In “This Peptide Stack Prevents or Fixes Ozempic Face Fast! (Doctor Explains)”, Dr. Jones, DC discusses TB-500. What he says, in short:

He says TB-500 works more broadly across the body than BPC-157 does.
He says research shows it helping cells migrate to where repair is needed and supporting tissue remodeling across a wider area.
He describes the division of labor as BPC-157 prepping the site and TB-500 moving the repair machinery in.
He says the mechanisms are real and consistent and that this is exactly why the two get stacked together.
He says nothing in the stack, TB-500 included, puts muscle back on the frame or slows how fast muscle is lost during rapid weight loss.

TB-500 works more broadly.

In “Doctor Explains GHK-Cu the Glow & Grow Peptide”, Dr. Jones, DC discusses TB-500. What he says, in short:

He describes TB-500 as the flexibility and range of motion player and a booster to BPC-157's healing.
He says it helps tissue glide and travels widely through the body to sites of injury.
He says it is not doing the skin collagen or hair work in the GLOW stack.
He says stacking all three means coming at a problem from three different angles.

Think of TB500 as the flexibility and range of motion player and a booster to BBC's healing.

In “Doctor Explains How the FDA Vote Changes BPC-157, TB-500, KPV & MOTS-c”, Dr. Jones, DC discusses TB-500. What he says, in short:

He says TB-500 was one of four compounds heard and voted on in a single day for placement on the 503A bulk list.
He says a speaker asking the committee to approve it told the room TB-500 is seven amino acids, while a late submission from a 503A compounding pharmacy prepared by a licensed pharmacist said it typically refers to a 17 amino acid fragment.
He points out that neither number came from the FDA and that both came from the side asking the agency to say yes.
He says that submission also stated the exact sequence can vary between vendors.
He says the FDA presenter read the discrepancy aloud and told the room it was their own side telling them this.
He frames this as a characterization and documentation problem rather than a safety finding against the compound.
He discloses that he runs BPC-157 and TB-500 on his own body and that his clinic prescribes several of these compounds, so he has a stake in how the ruling lands.

That document said TB-500 typically refers to a 17 amino acid fragment, and that the exact sequence can vary between vendors.

Seven or 17, and the FDA presenter reading it out loud said it plainly to the room, this is you telling me this.

In “Doctor Reveals The 10 Most POWERFUL Peptide Stacks (Science Backed Peptides)”, Dr. Jones, DC discusses TB-500. What he says, in short:

He describes TB-500 as a fragment of thymosin beta 4 that appears to promote cell migration to injury sites.
He says it moves cells where they need to go and brings blood supply with them, while BPC-157 is the heavy hitter for the blood supply and the healing itself.
He describes a range starting at 1 milligram and going up to 2 milligrams, which he restates as 2,000 micrograms, for heavy healing needs.
He says the duration again runs from 1 to 6 months with a break.
He criticizes companies that put BPC-157 and TB-500 into one vial at the same dose, saying that is not the best way to approach it.

TB500 1 milligram SL 10000 micrograms all the way up to 2 milligrams 2,000 micrograms for heavy healing needed.

Common questions

Is TB-500 approved by the FDA?

No. It is not an FDA-approved drug. The fragment is on FDA's list of bulk drug substances nominated for compounding use and then withdrawn, listed there as Thymosin Beta-4, Fragment.

Has the actual TB-500 fragment been tested in people?

No human study of the short fragment sold as TB-500 was found. Every human trial in the record used the full-length thymosin beta-4 protein, which is a different, larger molecule.

What was the full protein tested for in humans?

A 73-person trial tested it for leg ulcers and found it about as safe as placebo, with a minority of treated patients healing fully. A 9-person trial tested it as eye drops for severe dry eye and reported less discomfort and surface damage than placebo. A 96-person heart attack trial found no statistically significant main result, though a smaller subgroup showed smaller areas of heart damage.

Why does the fragment versus full protein difference matter?

Because the product sold to consumers as TB-500 is a smaller piece of the full protein, and no one has tested whether that piece behaves the same way in people. Results from the full protein cannot be assumed to apply to the fragment.

Is there human safety data for the TB-500 fragment specifically?

No. The eye drop and leg ulcer safety data all cover the full-length protein. No human safety study of the fragment was found.

What is thymosin beta-4?

A natural protein found in almost every human cell that helps cells move and rebuild. It is not itself the product marketed as TB-500.

Will this page tell me how much TB-500 to use?

No. We do not publish amounts or schedules for any peptide. That decision belongs with a licensed doctor.

Sources

Bubb (2003). PMID 12852258
Goldstein (2012). PMID 22074294
Guarnera (2010). PMID 20536470
Hannappel (2007). PMID 17468232
Kleinman (2016). PMID 27450738
Pipes (2016). PMID 27450736
Sosne (2015). PMID 25826322
Zhang (2025). PMID 41229390

The fragment sold as TB-500 appears on the FDA list of bulk drug substances nominated for compounding and then withdrawn, listed there as Thymosin Beta-4, Fragment (LKKTETQ), under the heading Bulk drug substances nominated but withdrawn, over concerns about immune reactions and peptide related impurities, and FDA states it has found no human exposure data for it. It is not an FDA-approved drug. Checked 08-26-2026.

Want these studies next to every other one on the site?

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TB-500: what it is and what the research actually shows

Quick facts

Benefits

Reported side effects

Safety, before anything else

TB-500 (thymosin beta-4 fragment)

How to read the grades

TB-500 (thymosin beta-4 fragment)

What has been studied

Safety signals in the studies

Where it stands with regulators

What is missing

Clinician commentary (YouTube)

Dr. Alex Tatem

Dr. Ashley Froese

Dr. Jones, DC

Common questions

Is TB-500 approved by the FDA?

Has the actual TB-500 fragment been tested in people?

What was the full protein tested for in humans?

Why does the fragment versus full protein difference matter?

Is there human safety data for the TB-500 fragment specifically?

What is thymosin beta-4?

Will this page tell me how much TB-500 to use?

Sources