The Local option in Washington and Oregon, coming soon at Nordic Pharmacy in Poulsbo. Nationally compounded for every other state.
TB-500 is a peptide of 7 amino acids that providers prescribe to support tissue repair, recovery after hard training and healthy tendons and muscles. It is the active region of thymosin beta-4, a protein the body makes, and it is one of six peptides in the October 2026 federal compounding policy.
What is TB-500?
TB-500 is a synthetic peptide with the sequence Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln, seven amino acids long [5]. That short sequence is the actin-binding region of thymosin beta-4, a larger protein that researchers have followed for decades because of its role in cell movement and repair [1][3]. Actin is the protein that lets cells change shape and move, which is what they need to do to rebuild tissue. TB-500 carries that working region in a small, focused peptide.
The federal policy names TB-500 acetate, given as an injection under the skin or into the muscle, as one single ingredient [5].
What is TB-500 prescribed for?
A provider prescribes TB-500 to support:
- Tissue repair after a hard season of training, racing or work on your feet
- Muscle and tendon recovery, so you can keep showing up for the sport you love
- Skin and soft tissue recovery
- Staying strong and active as you get older
Your provider looks at your history, your activity and your goals, then decides whether TB-500 fits your plan.
What has research looked at?
Thymosin beta-4 and its active region have a rich research record in repair.
- The 7-amino-acid region itself. A 2003 study in Wound Repair and Regeneration found that thymosin beta-4 accelerated skin repair in aged mice, with more cell migration and collagen. The seven-amino-acid peptide LKKTETQ, the sequence in TB-500, promoted repair in aged animals comparable to the full protein [1].
- Tendon. A 2020 study in Materials Science and Engineering C loaded thymosin beta-4 into tendon-like fiber scaffolds. It boosted the migration, growth and tendon-type development of human adult stem cells [2].
- Regeneration and healthy aging. A 2023 review in International Immunopharmacology describes thymosin beta-4 promoting cell migration and survival in the heart, and lays out why researchers see it as a lead for regenerative and anti-aging research [3].
Who is TB-500 for?
- The masters rower on Lake Washington whose shoulders and back feel every 5 am piece through the Montlake Cut.
- The backcountry skier finishing a spring of laps at Crystal Mountain and Stevens Pass, ready to rebuild before trail season.
- The ultimate player at Magnuson Park with a hamstring that keeps asking for attention.
- The parent who logged a summer of Olympic Peninsula trail miles with a kid in a carrier and wants to feel good doing it again next year.
Your visit with Arora Health
BrightSide care is provided by Arora Health, the Seattle practice led by Dr. Shannon Arora and Dr. Sean Arora. Their providers know peptides well and are excited to offer them.
- Start an online visit from home. Tell us how you train, what is holding you back and where you want to be.
- A Seattle-based Arora Health provider reviews it and builds a plan for you, including whether TB-500 fits.
- For patients in Washington and Oregon, Nordic Pharmacy in Poulsbo, a licensed Washington compounding pharmacy, fills your prescription. Everywhere else, our national pharmacy partners fill it. Either way it ships to your door.
- Follow up with your provider in your BrightSide patient portal as your plan moves along.
Every prescription gives 50 meals a month to those in need. See how on our giving page, and see how we choose pharmacies on our pharmacy network page.
How is TB-500 supplied?
| TB-500 | |
|---|---|
| Form | Compounded TB-500 acetate, single ingredient |
| Route | Injection under the skin (subcutaneous) or into the muscle |
| How often | On the schedule your provider sets in your plan |
| Storage | As directed on the pharmacy label that comes with your prescription |
When can you get TB-500?
Soon. On October 30, 2026, the Department of Health and Human Services published a draft policy that opens a path for state-licensed 503A compounding pharmacies to compound TB-500 and five other peptides. HHS says the policy is meant "to expand and improve patient access" [4]. It works through enforcement discretion, and BrightSide, Arora Health and our pharmacy partner are getting ready now so we can start as soon as prescribing opens.
Join the list to be first.
When prescribing opens, an Arora Health provider will reach out to you.
Common questions
Is TB-500 the same thing as thymosin beta-4?
No. Thymosin beta-4 is the full protein. TB-500 is the seven-amino-acid actin-binding region of it, made as its own small peptide. Researchers have shown that this short region can promote repair in aged animals comparably to the full protein [1].
Is TB-500 an injection?
Yes. The federal policy lists TB-500 for injection under the skin or into the muscle. Your provider shows you how in your plan, and you can ask questions in your patient portal.
Can TB-500 come in the same vial as BPC-157?
No. The federal policy allows one active ingredient per product, so every BrightSide peptide is a single ingredient. Your provider decides which peptide fits your plan.
Related peptides
- BPC-157: recovery and repair, prescribed to support tendon and ligament recovery and a healthy gut lining.
- MOTS-c: energy and metabolic, prescribed to support energy and healthy aging.
- Epitalon: sleep and healthy aging, prescribed to support restful sleep.
- See all six on the peptide hub.
Sources
- Philp D, Badamchian M, Scheremeta B, Nguyen M, Goldstein AL, Kleinman HK. Thymosin beta 4 and a synthetic peptide containing its actin-binding domain promote dermal wound repair in db/db diabetic mice and in aged mice. Wound Repair and Regeneration, 2003. https://pubmed.ncbi.nlm.nih.gov/12581423/ (DOI https://doi.org/10.1046/j.1524-475x.2003.11105.x)
- Wu S, Zhou R, Zhou F, Streubel PN, Chen S, Duan B. Electrospun thymosin beta-4 loaded PLGA/PLA nanofiber/microfiber hybrid yarns for tendon tissue engineering application. Materials Science and Engineering C, 2020. https://pubmed.ncbi.nlm.nih.gov/31753373/ (DOI https://doi.org/10.1016/j.msec.2019.110268)
- Bock-Marquette I, Maar K, Maar S, et al. Thymosin beta-4 denotes new directions towards developing prosperous anti-aging regenerative therapies. International Immunopharmacology, 2023. https://pubmed.ncbi.nlm.nih.gov/36709593/ (DOI https://doi.org/10.1016/j.intimp.2023.109741)
- HHS, Enforcement discretion policy regarding 503A compounding using certain peptide bulk drug substances, notice of availability, 91 FR 68526, October 30, 2026. https://www.govinfo.gov/content/pkg/FR-2026-10-30/html/2026-22192.htm
- HHS, Enforcement discretion policy regarding 503A compounding using certain peptide bulk drug substances, Appendix A and B. https://www.hhs.gov/sites/default/files/hhs-503a-peptide-enforcement-discretion-policy-appendix-b.pdf
Compounded peptides are not FDA approved and will be available by prescription from a licensed 503A pharmacy once prescribing opens.
