Healing & recovery
The body's natural healing peptide that accelerates tissue repair and reduces inflammation.
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Thymosin Beta-4 is a 43-amino-acid peptide found throughout your body, where it serves as a natural signal for tissue repair and immune function. It is studied for speeding wound healing, reducing inflammation and scar formation, and helping injured eyes heal; it can be given as eye drops for corneal conditions as well as by injection. It is a research compound, not FDA approved, with evidence from moderate (Phase 1-2) human trials.
Thymosin Beta-4 is a healing peptide that your body naturally produces in almost every cell. Think of it as a repair signal that tells cells to migrate to damaged areas, promote new blood vessel growth, reduce inflammation, and prevent cell death. It works like a master switch for your body's wound healing system. When you inject it, you're essentially amplifying your body's own healing response, making wounds close faster and scars less noticeable.
Thymosin Beta-4 is used in research for restoring immune function, speeding wound healing, repairing tissue after trauma, helping the heart recover after a heart attack, and anti-aging applications, drawing on both its immune and tissue-repair properties.
Thymosin Beta-4 works mainly by holding actin building blocks in reserve (actin sequestering). It binds actin monomers (G-actin, single building blocks of the cell's inner scaffold) and keeps them from joining into actin filaments (long strands). This controls cell motility (movement) and lets cells migrate, which is critical for closing wounds and remodeling tissue. Tβ4 also raises anti-apoptotic proteins (the Bcl-2 family, proteins that block programmed cell death), which protects cells from damage-induced death. It promotes angiogenesis (growth of new blood vessels) by switching on the VEGF pathway (a blood-vessel growth signal) and survival signals for endothelial cells (cells lining blood vessels). Its anti-inflammatory effects come from lowering pro-inflammatory cytokines (inflammation signals) TNF-alpha and IL-6 while keeping immune function. It also helps keratinocytes and epithelial (surface-lining tissue) cells (skin and surface cells) move, through integrin signaling (cell-surface grip proteins) and growth factor interactions (growth signals). These coordinated actions lead to faster tissue repair, less scarring through lower myofibroblast activity (scar-making cell activity), and better functional recovery of damaged tissue.
Evidence check
Some human studies
It has been tested in people, but only in small or early-stage studies. Promising, but not yet proven the way an approved medicine is.
Every numbered marker on this page links to one of the 6 sources at the bottom.
Wound Healing
Primary clinical focus with Phase 2 trials in pressure ulcers and venous stasis ulcers showing significant acceleration of healing and improved outcomes
Inflammation Reduction
Multiple mechanisms reduce pro-inflammatory cytokines while preserving beneficial immune function, with documented benefits in corneal inflammation and systemic inflammatory conditions
Tissue Regeneration
Multifaceted approach promoting cell survival, migration, and angiogenesis across multiple tissue types including skin, cornea, and muscle with strong mechanistic support
The most-asked question
The research-reported range is 2–5 mg, twice weekly. Studies used different doses for different situations — find yours:
Tissue repair, Recovery
2-5 mg (community injectable practice for 'TB-500')
Documented community/research-practice injectable dosing for tissue repair; thymosin beta-4 has ~100% bioavailability (how much actually gets absorbed and used) by the subcutaneous (under the skin) route 1. Not an FDA-approved use.
Neurotrophic keratopathy (a corneal disease from nerve damage), Dry eye
0.1% (1 mg/mL) RGN-259 solution, 1 drop
0.1% RGN-259 eye drops used in phase III trials for neurotrophic keratopathy (a corneal disease from nerve damage) and dry eye, applied several times daily for about 4 weeks 5.
Cardiac repair, Clinical research
450-1200 mg
Doses studied in the RGN-352 acute myocardial infarction clinical program, given IV after PCI 6.
The ceiling: 5 mg per injection; up to 1260 mg IV shown safe in Phase 1 trials
Reconstitution, in plain words
Peptides usually arrive as a freeze-dried powder in a small vial. “Reconstitution” just means adding sterile water back in so you can measure a dose. Here's how it works for Thymosin Beta-4:
For a 5 mg vial: Add 5 mL bacteriostatic water = 1 mg/mL solution. Each 0.1 mL = 0.1 mg (100 mcg)
Desired dose (mg) × mL per mg concentration = volume to inject. Example: 2 mg dose from 1 mg/mL solution = 2 mL
Three quick questions — your vial, your water, your dose — and it tells you the exact syringe mark. “Find dose amount” is preloaded with Thymosin Beta-4's recorded schedule.
Injection sites & technique
Injection just under the skin (subcutaneous (under the skin))
Timing
Morning or evening (flexible)
Not affected by food intake
Best administered on different days than other injectable peptides to minimize injection site stress
The honest list
These show up most often. They usually fade as your body adjusts.
Mild redness at the site of injection, usually resolves within hours to a few days
What to do Ice pack immediately after injection, rotate injection sites, use proper sterile technique
Mild swelling or puffiness at injection site, typically mild and temporary
What to do Ice compress for 10-15 minutes after injection, elevate area if applicable
Worth knowing about, but most people never see these.
Occasional mild headache within 24 hours of injection, usually self-limiting
What to do Stay hydrated, rest, over-the-counter analgesics if needed
Small bruises around injection area, more common with improper technique or thin skin
What to do Use proper injection technique, ensure needle is sharp, apply ice immediately after injection
Temporary tiredness or fatigue within 24-48 hours of injection
What to do Ensure adequate sleep, stay hydrated, usually resolves without intervention
Rare, but if any of these happen, stop and contact a medical professional.
Extremely rare; would present with itching, hives, difficulty breathing (not reported in clinical trials)
What to do Seek immediate medical attention, discontinue use, have epinephrine available if history of severe allergies
Week by week
Is it right for you?
This is general educational information. Always consult with a healthcare provider before starting, stopping, or modifying any peptide therapy. Do not self-diagnose or treat serious medical conditions.
Accelerates healing of surgical wounds and reduces post-operative inflammation and scarring
Helps pressure ulcers, venous stasis ulcers, and other slow-healing wounds progress faster
Supports repair of damaged tissues from injury, burns, or degenerative conditions
Thymosin Beta-4 is a naturally occurring peptide found in all cells and body fluids in the human body. Clinical trials have demonstrated excellent safety even at very high doses. IV studies showed doses up to 1260 mg were well tolerated with no serious adverse events.
Multiple Phase 1, Phase 2, and Phase 3 clinical trials are complete. The Phase 1 study showed that blood levels rose in proportion to the dose and that the half-life (how long it stays active in your body) got longer at higher doses, which points to predictable and safe dosing.
Keeping it good
Keep in original vial at 2-8°C. Protect from light and freezing. Stable for 36+ months when properly stored
Store at 2-8°C in refrigerator. Do not freeze reconstituted solution
Not our opinion — the published record
2012
This study investigated the properties and effects of Thymosin Beta-4, contributing to our understanding of its mechanism of action and potential therapeutic applications.
Goldstein AL, Hannappel E, Sosne G, et al.
2010
This study investigated the properties and effects of Thymosin Beta-4, contributing to our understanding of its mechanism of action and potential therapeutic applications.
Philp D, Kleinman HK
2010
This study investigated the properties and effects of Thymosin Beta-4, contributing to our understanding of its mechanism of action and potential therapeutic applications.
Shrivastava S, Srivastava D, Olson EN, et al.
2003
This study investigated the properties and effects of Thymosin Beta-4, contributing to our understanding of its mechanism of action and potential therapeutic applications.
Badamchian M, Fagarasan MO, Danner RL, et al.
2022
Sosne G, Ousler GW, et al.
2011
RegeneRx Biopharmaceuticals (NCT01311518)
If this isn't the right fit
Your questions
Yes. TB-500 is the common name used in research and bodybuilding communities, while Thymosin Beta-4 is the formal scientific name. They refer to the identical 43-amino acid peptide. The commercial development name being used in clinical trials is RGN-259 for ophthalmic (eye) applications.
Most people notice initial improvements in inflammation and pain within 2-3 weeks. Visible wound healing improvements typically appear around week 3-4. Maximum benefits usually develop over 8-12 weeks. Some effects continue improving even after completing a cycle due to ongoing tissue remodeling.
Not yet for systemic (affecting the whole body) use. Phase 3 clinical trials have been completed, but FDA approval for RGN-259 (the commercial ophthalmic formulation) is still pending. Research peptides are available from specialized suppliers, but regulations vary by location. Consult local regulations and healthcare providers.
Very safe. Phase 1 clinical trials demonstrated that IV doses up to 1260 mg were well tolerated with no serious adverse events in healthy volunteers. Multiple daily injections for 14 days were safe. Subcutaneous (under the skin) doses of 2-5 mg are well below these safety thresholds. The peptide is naturally occurring in your body, which contributes to its favorable safety profile.
No. Pregnancy is a contraindication because safety data in pregnant women is insufficient. While Thymosin Beta-4 is naturally present in the body, the effects of therapeutic dosing during pregnancy and lactation have not been adequately studied. Consult your healthcare provider if you become pregnant during or planning treatment.
Missing one dose in your weekly schedule won't significantly impact results. Simply take the next scheduled dose when you remember. Don't double-dose to make up. If you miss multiple doses, healing may be delayed, so consistency is important for optimal results.
Yes, it pairs well with complementary peptides like BPC-157 (synergistic tissue repair), Ipamorelin (growth hormone support), or collagen peptides (structural support). Stagger injection days to minimize site stress. Always consult with a healthcare provider before combining multiple therapies.
It's most effective for chronic wounds, surgical wounds, and tissue injuries. Phase 2 trials showed benefits for pressure ulcers and venous stasis ulcers. It's also studied for corneal healing and dry eye. However, if infection is present, antibiotics are necessary alongside treatment. Severely compromised circulation or severe underlying diseases may limit effectiveness.
6 sources
Every numbered marker on this page points to one of these. Same sources, same numbering as the Thymosin Beta-4 research profile on Peptide Initiative.
Want the deep science?
Every claim on this page traces back to the research database behind Peptide Initiative — studies, citations, clinical trial data, and the technical detail we deliberately left out here.
Open the research profileThis guide is education, not medical advice. Thymosin Beta-4 is a research compound that is not FDA-approved for human use. Talk to a clinician before taking anything.
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