How to track TB-500
TB-500 is not FDA-approved for any use, and FDA says it has not identified any human exposure data for it. If you are keeping a record, start with the name: write down exactly what the label says, because "TB-500", "thymosin beta-4" and "thymosin alpha-1" are different substances. Then log the vial strength, lot number, mixing date and liquid added, each entry's date, time, amount and site, and any reaction. The calculator below does vial arithmetic with the dose left blank.
What to log for each dose
Keep one row per vial and one row per entry. The vial row matters most, because the label is your only description of the product.
| Field | What to write | Why it matters |
|---|---|---|
| Name exactly as labelled | "TB-500", "TB-500 acetate", "thymosin beta-4" or whatever is printed | FDA names TB-500 as "thymosin beta-4, fragment (LKKTETQ)", a short piece of the larger thymosin beta-4 protein. A vial labelled with the full protein name may not contain the same thing. |
| Vial strength and lot | The mg on the label and the lot or batch number | This links any reaction to a specific supply. |
| Mixing record | Date mixed, liquid added in mL, resulting concentration | Needed for every later amount. The reconstitution calculator does the division. |
| Each entry | Date, time, the amount you were given in mcg or mg, syringe units if measured | One unit per column avoids mix-ups. |
| Site | Area and side | This shows whether a reaction follows one area. |
| Reactions | What, when it started, a severity from 1 to 5, how long it lasted | FDA has found no human exposure data, so there is no reference list of expected effects. |
| Storage | The label's storage conditions and any time the vial was outside them | There are no FDA-reviewed storage instructions. |
The printable peptide log sheet and the spreadsheet template have these columns, matching the PeptideMate web app export.
TB-500, thymosin beta-4 and thymosin alpha-1 are not the same
FDA describes TB-500 as a fragment of thymosin beta-4 with the sequence LKKTETQ. Thymosin beta-4 itself is a larger protein, and thymosin alpha-1 is a different peptide that FDA reviewed separately. Products are sometimes sold under one name and described with another. A log that records the exact wording on each vial avoids treating two different products as one.
If you switch suppliers, start a new vial record rather than continuing the old one, even if the name looks the same.
TB-500 vial arithmetic
Choose the vial strength on your label (2, 5 or 10 mg) and enter the liquid that was added. Then enter the amount you were given. We do not suggest one, and the field starts empty. You get the concentration, the volume and the U-100 syringe units.
Enter the amount your prescriber gave you. We don't suggest one. The 2 mg, 5 mg and 10 mg vial pages have full unit charts. They are generic arithmetic, the same for any compound.
Storage
There are no FDA-reviewed storage instructions for TB-500. Use the conditions printed on the label or certificate, and ask a pharmacist if they are missing. Record those conditions, the mixing date and any time the vial was warmer than stated. If the label gives no storage conditions at all, write that down too.
See peptide storage questions for how to keep a storage record that is useful later.
Half-life
There is no labelled human half-life for TB-500, because there is no FDA-approved label, and FDA reports no human exposure data. This site does not repeat figures from other websites. The half-life calculator accepts a value if a clinician gives you one.
What to record about side effects
A 2026 review of approved and unapproved peptide therapies found that "rigorous human safety data are scarce". There is no established list of expected reactions, so record everything new: the site, the time since the entry, a severity from 1 to 5, how long it lasted and the vial's lot number.
If you see a clinician, show them the log and the vial label. What to share with your doctor lists what to bring.
Red flags: when to contact a clinician
These general signs need help straight away, whatever you are using.
- Call 911 or your local emergency number for signs of a severe allergic reaction: difficulty breathing or wheezing, or swelling of the face, eyes or tongue. MedlinePlus describes anaphylaxis as an emergency that needs medical attention right away.
- Contact a clinician if an injection site becomes red, warm, swollen and tender, if it drains pus, if red streaks spread from it, or if you develop a fever with chills. These are signs of a skin infection.
- Contact a clinician about any reaction that is new, spreading or getting worse, and show them the vial label and lot number.
You can report a reaction to FDA through MedWatch, including for a product that is not FDA-approved.
Free TB-500 log template
A CSV for Google Sheets, Excel or Numbers, or the printable peptide log sheet to print. Free, no sign-up.
Or use PeptideMate: sites on a body map, vial and pen dates, reminders, and the same CSV columns. The web app is free in any browser.
For Android, iPhone, iPad and Mac.
TB-500 tracking questions
Is there a TB-500 tracker app?
PeptideMate can keep a TB-500 record: enter the name exactly as on the vial, add the vial with its strength, lot and mixing date, and log each entry with its site. It is for record keeping only. It does not recommend TB-500, doses or sellers.
Is TB-500 the same as thymosin beta-4?
No. FDA describes TB-500 as thymosin beta-4, fragment (LKKTETQ), a short part of the larger thymosin beta-4 protein. Record the exact name on each label.
Is TB-500 FDA-approved?
No. FDA lists it among bulk drug substances that may present significant safety risks, now as nominated but withdrawn from category 2, and says it has not identified any human exposure data. FDA's July 2026 briefing proposed not adding it to the 503A bulks list.
How do I work out the concentration of a TB-500 vial?
Divide the vial strength in mg by the liquid added in mL. For example, 5 mg in 2 mL is 2.5 mg per mL. The calculator on this page converts the amount you were given into mL and syringe units, and does not suggest an amount.
Sources
- Certain bulk drug substances for use in compounding that may present significant safety risks, US Food and Drug Administration, content current as of 22 April 2026. Used for: BPC-157 and TB-500 listed as "nominated but withdrawn" from category 2, with FDA's safety-risk text.
- Bulk drug substances nominated for use in compounding under section 503A: categories 1, 2 and 3 (updated 14 May 2026), US Food and Drug Administration. Used for: BPC-157 and TB-500 are not in category 1, 2 or 3.
- July 23-24, 2026: Meeting of the Pharmacy Compounding Advisory Committee, US Food and Drug Administration, content current as of 6 August 2026. Used for: BPC-157 and TB-500 were presented to the committee for the 503A bulks list; no outcome is posted.
- FDA briefing document: TB-500-related bulk drug substances (TB-500 free base and TB-500 acetate), Pharmacy Compounding Advisory Committee, July 23-24, 2026, US Food and Drug Administration. Used for: FDA proposed not adding TB-500 free base or acetate to the 503A bulks list.
- December 4, 2024: Meeting of the Pharmacy Compounding Advisory Committee, US Food and Drug Administration. Used for: Thymosin alpha-1 reviewed as a separate bulk drug substance.
- Mendias CL, Awan TM. Safety and efficacy of approved and unapproved peptide therapies for musculoskeletal injuries and athletic performance. Sports Med 2026;56(8):1921-35, PubMed (US National Library of Medicine), PMID 41966639. Used for: Rigorous human safety data are scarce.
- Anaphylaxis, MedlinePlus, US National Library of Medicine, reviewed January 2026. Used for: Signs of a severe allergic reaction that need emergency care.
- Cellulitis, MedlinePlus, US National Library of Medicine, reviewed April 2025. Used for: Signs of a skin infection and when to contact a provider.
- MedWatch: The FDA Safety Information and Adverse Event Reporting Program, US Food and Drug Administration. Used for: How patients report side effects to FDA.
Other tracking pages
- How to track semaglutide (Ozempic, Wegovy, Rybelsus)
- How to track tirzepatide (Mounjaro, Zepbound)
- How to keep a retatrutide log
- How to track BPC-157
Record keeping only: this page does not recommend TB-500, a dose, a schedule or a source. See the medical disclaimer.