TB-500
A synthetic peptide related to thymosin beta-4, sold for tissue repair. Most research is on full-length thymosin beta-4 in cells and animals, and only one of 80 studies in a 2026 review evaluated TB-500 itself.
How it is offered
Priced With Your Plan
Pricing
Your clinician sets the plan. Pricing is shown before you authorize any charge.
TB-500 requires a written prescription from a licensed clinician and is prepared by a licensed pharmacy for an individual patient. Compounded medications are not FDA-approved or evaluated for safety, effectiveness or quality. Evidence standards.
Start Your Assessment →What Is TB-500?
Thymosin beta-4 is a naturally occurring peptide that binds actin, a protein cells use to move, and is studied for its role in repairing skin, eye, heart and nervous-system tissue. TB-500 is the name of a synthetic product related to it.
A forensic analysis of a product sold as TB-500 found a short fragment of thymosin beta-4, not the whole molecule. So evidence about thymosin beta-4 does not automatically apply to TB-500, and we keep the two apart.
Good to Know
- Prescribed only after a clinician reviews your history.
- Dose and course are set by your clinician, not by you.
- Results vary, and we do not promise outcomes.
Who It Is For
Eligibility
Competitive Athletes
TB-500 is on the WADA Prohibited List. A prescription does not establish sporting eligibility, so we ask about anti-doping rules before presenting any option.
Often a Good Fit If
- ✓A tendon, ligament or soft-tissue injury that has not resolved with standard care
- ✓Willing to pair it with physical therapy or a structured return to training
- ✓Comfortable with very limited human evidence
- ✓Open to a defined course with a clinician-reviewed endpoint
Not Prescribed If
- —Pregnancy, breastfeeding, or actively trying to conceive
- —Active or recent cancer diagnosis, or a history your clinician judges to carry risk
- —Expecting a guaranteed or fast outcome rather than a considered trial
- —Subject to anti-doping rules that prohibit it
Read Before You Decide
Key Risks, Stated Plainly
There is no clinical safety record for TB-500 itself. Thymosin beta-4 has been given in trials as eye drops and in other early studies, which does not establish the safety of injected TB-500. Thymosin beta-4 promotes cell migration and new blood vessel growth in laboratory work, which is a theoretical reason for caution in anyone with a cancer history. TB-500 sits on FDA's Category 2 safety-risk page.
Contact care the same day for
Significant swelling or pain at an injection site, signs of allergic reaction, or any new or unexplained symptom during a course.
What Is Measured
Function and Pain
A baseline you rate at the start, then again at each check-in.
Training Load
What you can do compared with what you could before the injury.
Injection-Site Tolerance
Reviewed early, when most reactions appear.
Anti-Doping Check
Competitive athletes are screened against current sport rules first.
Course Endpoint
A scheduled reassessment against your original goal.
A Clearer Path Forward
How Clinicians Review Your Response
You and Your Clinician Look at the Same Data
Symptoms you report, laboratory results and, if you connect one, wearable trends are reviewed together before any change.
A Physician-Led Review Every 90 Days
Included in your monthly price. Your clinician decides whether to continue, adjust the dose, change course or stop.
Clinical Judgment Decides
Measurements inform the decision. They do not make it, and no dashboard changes your dose on its own.
Your Care Sequence
01
Questionnaire
Share your goals, history and any sport or work rules in about ten minutes. No card required.
02
Video Visit
Your clinician reviews your history and medications, explains the evidence plainly, and decides whether this fits you.
03
Delivery
If prescribed, medication ships from a licensed pharmacy with supplies and written instructions.
04
Reassessment
A scheduled review decides whether to stop, extend or change course. Courses are not renewed by default.
Common Questions About TB-500
Is TB-500 the Same as Thymosin Beta-4?+
No. A product sold as TB-500 has been found to contain a short fragment of thymosin beta-4, not the whole 43-amino-acid molecule. Evidence on one does not transfer automatically to the other.
What Does the Research Show?+
A 2026 scoping review of 80 studies found most were in cells or animals, most evaluated thymosin beta-4 rather than TB-500, and only one directly evaluated TB-500. Human evidence was concentrated in eye and skin-wound settings, with little on tendon, ligament or muscle.
Did Thymosin Beta-4 Work in Human Trials?+
In a Phase II trial of 72 people with dry eye, thymosin beta-4 eye drops missed both primary endpoints, though some secondary measures improved. That tested eye drops, not injections.
Is TB-500 FDA-Approved?+
No. It is not an FDA-approved drug, and it appears on FDA's Category 2 safety-risk page.
Can I Use It If I Compete in Sport?+
Probably not. TB-500 is on the WADA Prohibited List, and a prescription does not change that.
Is It Available Through SOVRYN?+
TB-500 is prescribed only after a clinician reviews your history and decides it fits. Start with the assessment and your clinician will tell you what is and is not appropriate.
Still unsure? Message the care team before you join. No account needed.
Published Research
What the Published Science Shows
1 of 80
Studies in a 2026 review of thymosin beta-4 that directly evaluated TB-500 itself.
72
People in a Phase II eye-drop trial of thymosin beta-4 that missed its primary endpoints.
7
Amino acids in the fragment found in a product sold as TB-500, versus 43 in full-length thymosin beta-4.
Figures come from the cited trials and reviews. They describe published research, not a forecast for any one person, and not a study of compounded formulations.
The Mechanism
The Proposed Mechanism
Actin Binding
Thymosin beta-4 binds actin, a protein that helps cells change shape and move.
Cell Migration
It is proposed to help cells and stem or progenitor cells move to an injury site.
Less Scarring
Reviews describe fewer myofibroblasts in wounds and decreased scar formation in laboratory work.
For Readers Who Want More
Deeper Evidence
What We Can and Cannot Tell YouEvidence and regulatory status+
What the Evidence Supports
Thymosin beta-4 binds actin and promotes cell migration after injury, with consistent findings in wound-healing models and early human work in eye and skin settings.
What It Does Not (Yet)
Almost no direct evidence on TB-500, little human evidence for tendon, ligament or muscle repair, and no clinical safety record for injected use. It is on the WADA Prohibited List.
Badge definitions and FDA category sourcing are on the Science page.
Illustrative Course StructureFinal dose set by your clinician+
Illustrative only and not a prescription. Dose, timing and length are set by your clinician and the compounding pharmacy.
| Phase | Approach | Duration | What We Watch |
|---|---|---|---|
| Baseline | Visit, labs where indicated | Before starting | Symptoms, relevant labs |
| Course | Clinician-set dose, held at the tolerated level | Defined by your clinician | Tolerance, response |
| Reassessment | Extend, stop or change course | At the scheduled review | Whether the goal was met |
Selected Studies
McGuire et al., 2026 (scoping review of thymosin beta-4 and TB-500; preprint, not peer-reviewed)
Of 80 included studies, most were in vitro or animal, most evaluated thymosin beta-4 rather than TB-500, and only one directly evaluated TB-500. Human evidence was concentrated in eye and skin-wound settings, with little for tendon, ligament or muscle.
Read the Source ↗Goldstein et al., Expert Opinion on Biological Therapy, 2012 (review of thymosin beta-4)
Describes thymosin beta-4 as a naturally occurring peptide that binds actin and promotes cell migration after injury, with ongoing clinical work in skin, eye, heart and nervous-system repair.
Read the Source ↗Sosne and Ousler, Clinical Ophthalmology, 2015 (Phase II, thymosin beta-4 eye drops)
In 72 people with dry eye, the two primary endpoints were not met, though some secondary measures improved. It tested eye drops, not injections, and it is the kind of human evidence that exists for thymosin beta-4.
Read the Source ↗Esposito et al., Drug Testing and Analysis, 2012
Identified a short acetylated fragment of thymosin beta-4 (Ac-LKKTETQ) in a product sold as TB-500, which the authors flagged as suspected for use in doping.
Read the Source ↗Renke and Chinellato, International Journal of Molecular Sciences, 2026 (review of 106 articles)
Reviewed the effects, safety and regulatory status of prominent therapeutic peptides, including unapproved ones, and concluded that further studies are needed before most new peptides can be used safely in humans.
Read the Source ↗
Start Your Assessment for Recovery Options
Ten minutes, no card, reviewed by a clinician.