Thymosin Beta-4
The body's natural healing peptide that accelerates tissue repair and reduces inflammation
Written by Michael Carroll — Owner, Director of Research · Reviewed by the Peptide Initiative Research Team · Editorial standards
Suggested dose
2 – 5 mg
Compound profile
Scientific & efficacy data
Healing & Recovery
Peptide profile
Moderate human trials
Thymosin Beta-4
2-5 mg (community injectable practice for 'TB-500') · Twice weekly
Molecular formula
C212H350N56O78S
- Mol. weight
- 4963
- CAS number
- 77591-33-4
- PubChem
- 45382195
- Developed · 1966
- Allan Goldstein
Albert Einstein College of Medicine / George Washington University
Amino acid sequence
SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGESWound 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
Dosing
How much do I take?
2 – 5 mg · once or twice weekly · subcutaneous injection
2 – 5 mg
Once or twice weekly
Covers all 3 documented dose levels · 3 administration routes · timing · dose-adjustment guidance.
Suitability
Is this right for me?
Best for recovering from injuries or surgery & improving wound healing speed
Best for
Post-Surgery Recovery
Accelerates healing of surgical wounds and reduces post-operative inflammation and scarring
Chronic Wound Management
Helps pressure ulcers, venous stasis ulcers, and other slow-healing wounds progress faster
Tissue Regeneration
Supports repair of damaged tissues from injury, burns, or degenerative conditions
Consider alternatives if
Do not use if
Use with caution if
Not sure?
Compare Thymosin Beta-4 with similar peptides to find the best fit for your goals.
Administration
How do I use it?
Subcutaneous injection · Intravenous injection
Route
Subcutaneous
Best sites
Covers reconstitution · step-by-step technique · storage · a sample daily schedule.
Safety
Is it safe?
2 common side effects · 2 serious
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 completed. Phase 1 study showed dose-proportional pharmacokinetics with increasing half-life at higher doses, indicating predictable and safe dosing.
Common side effects · experienced by some users
Injection site redness
Mild redness at the site of injection, usually resolves within hours to a few days
Management: Ice pack immediately after injection, rotate injection sites, use proper sterile technique
Injection site swelling
Mild swelling or puffiness at injection site, typically mild and temporary
Management: Ice compress for 10-15 minutes after injection, elevate area if applicable
Less common
These typically resolve with continued use or dose adjustment.
Stop and seek help if
- Severe allergic reaction or anaphylaxis
- Persistent injection site infection
- Significant systemic adverse effects
- Pregnancy is confirmed
- No improvement in healing after 12 weeks (reassess approach)
- Active systemic infection develops without antibiotic coverage
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.
With other peptides
- Caution:
- Caution:
- Caution:
- Caution:
With medications
- Caution:
- Caution:
- Caution:
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With supplements
- Safe:
- Safe:
- Safe:
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Effectiveness
How do I know it's working?
Moderate human trials · first signs weeks 1-2
Evidence level
Moderate human trials
(Phase 1-2)
Regulatory status
Research compound
Onset of effects
Moderate
(1-2 weeks)
How it works
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.
The deeper mechanism
Thymosin Beta-4 exerts its effects primarily through actin-sequestering mechanism: it binds to actin monomers (G-actin), preventing their polymerization into actin filaments. This modulates cell motility and enables cell migration—critical for wound closure and tissue remodeling.
Additionally, Tβ4 upregulates anti-apoptotic proteins (Bcl-2 family members), protecting cells from damage-induced death. It promotes angiogenesis through VEGF pathway activation and endothelial cell survival signals.
Anti-inflammatory effects occur through downregulation of pro-inflammatory cytokines (TNF-alpha, IL-6) while maintaining immune function. The peptide also enhances keratinocyte and epithelial cell migration through integrin signaling and growth factor interactions.
These coordinated mechanisms result in accelerated tissue repair, reduced scarring through decreased myofibroblast activity, and improved functional recovery of damaged tissues.
What to expect
Weeks 1-2
What you might notice
- Minimal visible changes yet (peptide accumulating in tissues)
- Possible mild injection site reactions (normal)
- Increased sense of well-being in some users
What's normal
- Small bruises at injection sites
- Slight redness that fades within hours
- No major systemic effects
What's next
- Continue twice-weekly dosing as prescribed
- Begin documenting wound appearance with photos
- Monitor for any adverse reactions
Weeks 3-4
What you might notice
- First visible signs of improved healing
- Reduced swelling or inflammation around injury
- Decreased pain levels
- Edges of wounds appearing cleaner and more defined
What's normal
- Increased granulation tissue formation (pink/red base)
- Wound contraction beginning
- Temporary increase in wound drainage (good sign of healing)
What's next
- Maintain consistent dosing schedule
- Take progress photos to track improvement
- Prepare for potential maintenance phase transition
Weeks 5-8
What you might notice
- Substantial improvement in wound appearance
- Significant reduction in inflammation
- Enhanced skin quality and appearance
- Reduced scarring or scar maturation progressing faster
What's normal
- Epithelialization (new skin formation) accelerating
- Wound size reduction visible
- Skin color normalizing
- Reduced need for wound care/dressings
What's next
- Consider transitioning to maintenance dosing (once weekly)
- Evaluate if healing goals are being met
- Discuss long-term maintenance plans with healthcare provider
Weeks 9-12
What you might notice
- Near-complete wound closure or significant closure
- Minimal inflammation remaining
- Scar tissue organizing and maturing
- Return to normal function in affected area
What's normal
- Continued scar remodeling over months
- Skin texture continuing to improve
- No limitations on activity (if healing complete)
What's next
- Complete intended cycle or transition to maintenance dosing
- Begin scar management if appropriate (topical treatments)
- Plan follow-up timeline with healthcare provider
Signs it's working
Physical Healing
- Visible reduction in wound size
- Decreased redness or inflammation
- Improved wound bed appearance (healthier tissue)
- Faster epithelialization (new skin formation)
- Reduced scarring or scar formation
- Return of normal skin texture
- Improved range of motion if musculoskeletal injury
Functional Improvement
- Decreased pain and discomfort
- Reduced swelling in affected area
- Faster return to normal activities
- Improved mobility or flexibility
- Better quality of sleep (less pain-related disruption)
- Increased confidence in affected body part
Not seeing results? Common reasons
- Infection in wound preventing healing (requires antibiotics alongside treatment)
- Inadequate dosing for severity of injury (may need to increase to 5 mg dose)
- Poor injection technique or site selection causing local issues
- Underlying health conditions affecting healing (diabetes, poor circulation, nutritional deficiency)
- Inconsistent dosing schedule or missed injections disrupting therapeutic rhythm
- Unrealistic timeline expectations (some injuries require 12+ weeks even with peptide support)
Key research
Clinical trials
Tested in people
12 registered studies, 2 still enrolling.
By phase
A trial spanning two phases is counted in both, so these can sum above the total. Observational studies carry no phase.
What kind of research
About 2,004 people took part in the studies that actually administered Thymosin Beta-4. Observational studies analyse the records of people already taking it — nobody was given anything for the study, so they are counted separately and cannot show cause and effect.
Most recent
TB-500 (Thymosin Beta 4 17-23 Fragment) for Cardiovascular Biomarkers in Stable ASCVD
Hudson Biotech
RGN-NK-302
Regentree LLC
SEER-3
Regentree LLC
Sources: ClinicalTrials.gov, the EU Clinical Trials Information System and ISRCTN, deduplicated so a study registered twice is counted once. A study is counted when Thymosin Beta-4 is named as an intervention; studies that only mention it in passing are not.
Questions
Frequently asked
Is Thymosin Beta-4 the same as TB-500?
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.
How long before I see results?
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.
Is Thymosin Beta-4 FDA approved?
Not yet for systemic 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.
How safe is Thymosin Beta-4 based on clinical trial data?
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 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.
Can I use Thymosin Beta-4 while pregnant or breastfeeding?
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.
What happens if I miss a dose?
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.
Can I combine Thymosin Beta-4 with other peptides?
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.
Does Thymosin Beta-4 work for all wound types?
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.
Further reading
History & related research
History · since 1966
The body's secret healing signal hidden in nearly every cell
A 43-amino acid peptide discovered in 1966 that acts as a master repair signal. Found in blood platelets, white blood cells, and most human tissues.
Read the full history of Thymosin Beta-4Ready for the protocol?
Every dosing tier, administration route, timing note, and dose-adjustment rule for Thymosin Beta-4, on one page.