Skip to content

Important Safety TB-500

TB-500 Injection (Compounded Thymosin Beta-4 Fragment, LKKTETQ)


Important Safety Notice



THIS IS A CUSTOM PRESCRIPTION MEDICATION INTENDED ONLY FOR YOU.

What is TB-500?

TB-500 is a lab-made peptide (a short chain of 7 amino acids, the building blocks of proteins). It copies one small piece of thymosin beta-4, a natural protein found in almost every cell that helps cells move and repair tissue. It is given as an injection under the skin (subcutaneous). It is intended only for adults 18 years and older.


Important: TB-500 is a compounded medication. It is NOT FDA-approved for any use, and no TB-500 product is approved in any country. It has not been reviewed by the FDA for safety, effectiveness, or quality.


TB-500 is not the same as thymosin beta-4. Research on the full thymosin beta-4 protein cannot be assumed to apply to TB-500.


What it is studied for: TB-500 is promoted for wound healing and soft tissue recovery. However, no studies have tested TB-500 in humans. In one lab study, TB-500 itself did not speed up wound closure in cells, though one of its breakdown products had a small effect. Results vary, and no specific outcome is guaranteed.


Regulatory status (as of October 2026): In May 2026, FDA staff recommended that TB-500 not be added to the list of ingredients pharmacies may use in compounding. On July 23, 2026, FDA's advisory committee voted to recommend adding it. That vote is not binding, and FDA has not issued a final decision. Availability may change based on that decision and the laws in your state.


Athletes: TB-500 is banned in sport by the World Anti-Doping Agency (WADA), and drug tests can detect it. If you are tested for drugs in competition, do not use this medication.


Note: This summary does not contain all possible safety information. It is not a substitute for advice from your healthcare provider. Always talk to your doctor or pharmacist before using this medication.

How to Use TB-500 Injection

  1. Prepare: Wash your hands. Check the vial label and beyond-use date (BUD). Do not use if the liquid is cloudy, discolored, or has particles. Wipe the vial top with a fresh alcohol swab.
  2. Draw the dose: Use a new, sterile needle and syringe every time. Draw only the dose shown on your prescription label. Never share needles, syringes, or vials.
  3. Where to inject: Inject under the skin into fatty tissue, such as the abdomen, thigh, or back of the upper arm. Clean the site with an alcohol swab and let it dry.
  4. Rotate sites: Use a different spot each time to reduce irritation. Do not inject directly into an injured, painful, or inflamed area unless your provider tells you to.
  5. Dispose safely: Place used needles and syringes in an FDA-cleared sharps container right away. Never throw loose needles in the trash

Important Usage Notes

Who Should NOT Use TB-500


Do not use TB-500 if you:


  • Have active cancer. Thymosin beta-4 is involved in cell movement and new blood vessel growth, which could in theory support tumor growth or spread. No cancer safety studies have been done.
  • Are pregnant, planning to become pregnant, or breastfeeding. No reproductive safety studies exist.
  • Have a known allergy or sensitivity to TB-500, thymosin beta-4, or any ingredient in the prescribed formulation
  • Are under 18 years of age
  • Are an athlete subject to drug testing (TB-500 is banned by WADA)

Important Warnings

No Human Safety Data

  • FDA found no human studies, case reports, or adverse event reports for TB-500 by any route. Its side effects in people are unknown.
  • No animal toxicity, cancer, genetic damage, or reproductive safety studies have been found.
  • Because so little is known, report any new or unusual symptom to your provider.


Immune Reactions

  • FDA warns that injected peptides may trigger the immune system. Injections under the skin carry a higher risk than injections into muscle or a vein. Impurities or clumped peptide particles may raise this risk.
  • Reactions may range from none to serious allergic reactions. Stop using and get medical help right away for hives, facial or throat swelling, wheezing, or trouble breathing.

Cancer

  • Tell your provider if you have a history of cancer or are being screened for it. Long-term cancer risk has not been studied.

Infection Risk

  • Any injection can cause infection. Watch for spreading redness, warmth, pus, blistering, or fever.

Product Quality

  • FDA found TB-500 ingredients are not well standardized, and products sold under this name may contain different substances. Use only product dispensed by a licensed pharmacy under your prescription.
  • Never use “research use only” TB-500 or combination “blend” products bought online.

Other Precautions

Talk to your doctor before using TB-500 if you:

  • Have cancer or a history of cancer
  • Have an autoimmune condition or a history of allergic reactions to medications
  • Have a planned surgery or dental procedure
  • Take any other peptides (such as BPC-157) or are using a combination peptide product

Alcohol and Cannabis

  • Limit alcohol and avoid cannabis and recreational drugs while using TB-500. How TB-500 interacts with these substances has not been studied.

Drug Interactions


Drug interactions with TB-500 have not been studied in humans. The concerns below are based on how thymosin beta-4 is thought to work. Tell your doctor about all medications you take, especially:



Always tell all your doctors and pharmacists that you are using TB-500 (subcutaneous injection), especially before starting any new medications or having surgery.

Possible Side Effects

Side effects of TB-500 in humans have not been studied. Based on other injected peptides, you may notice:


  • Injection site reactions: mild redness, swelling, tenderness, or soreness where you inject. These are usually temporary. Rotate sites to reduce irritation.
  • Headache, tiredness, or dizziness, especially when starting.
  • Mild nausea or stomach discomfort.


If any side effects become concerning, contact your doctor or call the number on your prescription label to speak with a pharmacist.


When to Seek Emergency Medical Help

STOP using TB-500 and get immediate medical attention if you experience:


  • Shortness of breath, wheezing, chest tightness, or swelling of the face, lips, tongue, or throat • Widespread hives, severe itching, or skin rash
  • Fever of 100.4°F (38°C) or higher
  • Blistering, spreading redness, warmth, or pus at an injection site
  • Severe muscle aches, nausea, vomiting, dizziness, or headache
  • Chest pain, fainting, or a racing or irregular heartbeat

Reporting Side Effects

If you experience any serious or unexpected side effects, report them to:


  • Pharmacy / Compounding Hub: 248-633-2880
  • FDA: 1-800-FDA-1088
  • FDA Online: www.fda.gov/medwatch


Important Safety TB-500 | Rugiet