TB-500: where it stands with the FDA, and what it costs
No FDA-approved drug contains it.
Go to clinicLowest per monthTB-500 injection
Ascend Vitality · from $99/mo (supply not stated, counted as 4 weeks: ≈ $106 per 30 days)
Go to clinicLowest at a clinic we link toTB-500 injection
Live Vital · $159.50/mo (supply not stated, counted as 4 weeks: ≈ $171 per 30 days)
Where TB-500 stands today
No FDA-approved drug contains TB-500 (the LKKTETQ fragment of thymosin beta-4). FDA had it in 503A Category 2 from September 29, 2023 until April 22, 2026 (nomination withdrawn). On July 23, 2026 the advisory committee voted 8-6 (1 abstention, per law-firm reports) to recommend listing it, against FDA staff's proposal. HHS's October 30, 2026 interim policy covers TB-500 acetate for subcutaneous or intramuscular injection only, single-ingredient, under ten conditions; it does not cover 503B facilities. It is not on the 503A or 503B bulks list.
For pharmacies compounding one patient's prescription (section 503A)
Not on the 503A bulks list and in no FDA category (removed from Category 2 on April 22, 2026 after its nominations were withdrawn). Since Oct 30, 2026 it is one of six peptides in HHS's interim enforcement discretion policy for 503A compounding, limited to the form and routes below and ten conditions.
“Bulk drug substances nominated but withdrawn ... Thymosin beta-4, fragment (LKKTETQ), also known as TB-500 Compounded drugs containing thymosin Beta-4, Fragment (LKKTETQ) may pose risk for immunogenicity for certain routes of administration due to the potential for aggregation as well as peptide-related impurities.”
““Thymosin Beta-4, Fragment (LKKTETQ),” also known as TB-500, has been removed from category 2 because the nomination was withdrawn by the nominator.”
HHS interim enforcement discretion policy (Office of the Secretary, not FDA)
“HHS does not intend to take enforcement action against a State-licensed pharmacy, Federal facility, or licensed physician compounding a drug product using a bulk drug substance in Appendix A.”
Form and routes HHS covers
“Based on the identified updated information, enforcement discretion for TB-500 acetate appropriate for subcutaneous or intramuscular injectable dosage forms that are compounded from API accompanied by a CoA meeting the conditions of this policy.”
“TB-500 was in Category 2 from September 29, 2023, until April 22, 2026, and neither the placement nor the removal changed its status under section 503A; CDER recommended against listing either form, and the PCAC voted in favor of both forms.”
One of the ten conditions: single-ingredient products only (no blends)
“The compounded drug product contains only a single Active Pharmaceutical Ingredient (API) listed in Appendix A.”
The Federal Register notice calls the policy a draft; written comments closed two weeks after publication
“HHS is announcing the availability of a draft”
21 CFR 216.23(a), the 503A bulks list itself: six substances (Brilliant Blue G, cantharidin, diphenylcyclopropenone, N-acetyl-D-glucosamine, squaric acid dibutyl ester, thymol iodide); none of the compounds in this file
“The following bulk drug substances can be used in compounding under section 503A(b)(1)(A)(i)(III) of the Federal Food, Drug, and Cosmetic Act.”
For outsourcing facilities (section 503B)
Not on the 503B bulks list and not in any 503B category (FDA's 503B nominations list, updated March 21, 2025, does not name it)
“Outsourcing facilities, which operate under section 503B of the Federal Food, Drug, and Cosmetic Act (FD&C Act), may not compound a drug product that includes a bulk drug substance unless: The bulk drug substance appears on a list identifying bulk drug substances for which there is a clinical need (the 503B bulks list), or”
The 503B bulks list holds five substances (diphenylcyclopropenone, glycolic acid, quinacrine HCl oral, squaric acid dibutyl ester, trichloroacetic acid); none of the compounds in this file
“FDA has evaluated the following bulk drug substances and determined that there is a clinical need for outsourcing facilities to compound drug products using these bulk drug substances under section 503B of the FD&C Act:”
The HHS policy names 503A compounders only; it does not cover 503B outsourcing facilities
“HHS does not intend to take enforcement action against a State-licensed pharmacy, Federal facility, or licensed physician”
The FDA's compounding advisory committee
23 July 2026: Should TB-500 (free base) and TB-500 acetate be placed on the 503A bulks list? (use FDA reviewed: wound healing). Vote: 8 yes, 6 no, 1 abstention (both forms), per law-firm reports. Committee recommended inclusion, against FDA staff's proposal; no FDA rule yet; HHS cited the vote in its Oct 30, 2026 interim policy
“VOTE: Should TB-500 (free base) be placed on the list? ... VOTE: Should TB-500 acetate be placed on the list?”
FDA warnings, recalls and letters
12 June 2023: Warning letter treating BPC-157 and TB-500 sold online as unapproved new drugs. (Warrior Labz SARMS (online seller)).
““BPC-157,” “TB-500,” ... products are not generally recognized as safe and effective for the above referenced uses and, therefore, are “new drugs” under section 201(p) of the FD&C Act, 21 U.S.C. 321(p).”
30 June 2023: Untitled letter after inspection; notes the pharmacy produced thymosin beta-4, which FDA treats as a biological product. (Revive Rx, LLC dba Revive Rx Pharmacy, Houston, TX (503A pharmacy)).
“Furthermore, the FDA investigator noted that your facility produced biological products, including HCG and Thymosin-Beta 4.”
21 October 2025: Recall of a BPC-157/thymosin beta-4 combination injection. Class II; recall initiated 2025-07-30, classified 2025-10-21, distributed nationwide. (GenoGenix LLC, Boca Raton, FL (registered 503B outsourcing facility)).
“BPC-157/Thymosin Beta-4 for Injection ... Lack of Assurance of Sterility”
21 October 2025: Recall of thymosin beta-4 injection. Class II; recall initiated 2025-07-30, classified 2025-10-21, distributed nationwide. (GenoGenix LLC, Boca Raton, FL (registered 503B outsourcing facility)).
“Thymosin Beta-4 (TB4) for Injection, 15mg, all presentations ... Lack of Assurance of Sterility”
20 January 2026: Warning letter: thymosin beta-4 is an unapproved new drug and a biological product with no BLA; epithalon cited among products with labeling defects (NAD+ findings listed under nad-plus). (GenoGenix LLC, Boca Raton, FL (registered 503B outsourcing facility)).
“Products such as Thymosin Beta-4 are unapproved new drugs under section 505 of the FDCA [21 U.S.C. § 355(a)] and also biological products under section 351 of the Public Health Service Act (PHS Act) [42 U.S.C. § 262].”
For athletes who are tested
Prohibited at all times (in and out of competition) (World Anti-Doping Agency, 2026 Prohibited List (in force 1 Jan 2026; WADA approved a 2027 list in Sept 2026, effective 1 Jan 2027, not read here)).
“Thymosin-ß4 and its derivatives e.g. TB-500”
Our reading
A 503A pharmacy can compound TB-500 acetate injections for a patient-specific prescription under HHS's enforcement discretion if it meets every condition; oral, nasal or topical TB-500 and blends (for example 'BPC-157 + TB-500' or 'Wolverine stack') fall outside it. Full-length thymosin beta-4 is a different molecule, not covered, and in January 2026 FDA told a compounder that thymosin beta-4 is a biological product needing a BLA; a product sold as 'thymosin beta-4' rather than 'TB-500 (LKKTETQ)' is therefore outside the policy.
Every source above was checked again on 14 November 2026.
What 59 clinics charge
- Ascend VitalityTB-500 injectionfrom $99/mosupply not stated, counted as 4 weeks: ≈ $106 per 30 days
- EnhancedTB-500 injectionfrom $109/mo
- PepScribeTB-500 injectionfrom $129/mo
- Try NovaTB-500 injection (15mg)$133/mo
- EverlifeTB-500 injection (15mg)from $145/mo
What TB-500 is
- What it is
- Thymosin beta-4 (synthetic fragment)
- How it works
- A synthetic version of part of thymosin beta-4, a protein involved in cell movement and tissue repair.
- How it is given
- Subcutaneous injection
- Also called
- thymosin beta-4, TB4
TB-500 side by side
About TB-500
Is TB-500 FDA-approved?
No. No FDA-approved drug contains TB-500. What clinics sell is compounded by a pharmacy for a prescription, and the FDA does not review compounded products before they are sold.
Is TB-500 legal in the US?
Whether a pharmacy may compound it for your prescription is what decides it. No FDA-approved drug contains TB-500 (the LKKTETQ fragment of thymosin beta-4). FDA had it in 503A Category 2 from September 29, 2023 until April 22, 2026 (nomination withdrawn). On July 23, 2026 the advisory committee voted 8-6 (1 abstention, per law-firm reports) to recommend listing it, against FDA staff's proposal. HHS's October 30, 2026 interim policy covers TB-500 acetate for subcutaneous or intramuscular injection only, single-ingredient, under ten conditions; it does not cover 503B facilities. It is not on the 503A or 503B bulks list.
How much does TB-500 cost?
59 clinics publish a price. The lowest that compares per month is from $99/mo at Ascend Vitality, and the middle of 44 clinics' lowest monthly prices is about $199. What a month buys differs by clinic, so each price lists what it includes. every TB-500 price
What forms does TB-500 come in?
Clinics sell it as injection (55 prices), other (8 prices).