TB-500

Not enough proof

A small piece of a natural body protein. People hope it helps recovery. It is not approved, and proof is missing.

Pending medical review Updated October 16, 2026

What is it?

TB-500 is a small piece of a protein called thymosin beta-4. Your body makes thymosin beta-4 on its own. TB-500 is made in a lab.

Why do people use it?

Some people say it helps muscles and injuries recover. These are claims. They are not proven facts.

Does it really work?

The FDA says it does not have enough safety information to know if TB-500 would cause harm in people.

Is it safe? Side effects

  • The FDA says it does not have enough safety facts about TB-500 in people.
  • The FDA warns your body might fight it like a germ. Doctors call this an immune reaction.
  • Products may have unwanted bits left over from how they were made.

Talk to your doctor

Do not start any peptide on your own. Ask a doctor first. We never share doses or tell you where to buy. Print our doctor questions sheet.

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FAQ

What is TB-500?

TB-500 is a small piece of a protein called thymosin beta-4. Your body makes thymosin beta-4 on its own. TB-500 is made in a lab.

Does TB-500 work?

The FDA says it does not have enough safety information to know if TB-500 would cause harm in people.

Is TB-500 legal in the US?

No. TB-500 is not an FDA-approved medicine. (The FDA is the US agency that checks if medicines are safe and work.) The FDA put TB-500 on a list of things that may be risky when a pharmacy mixes them into a medicine.

Related pages

Sources

Not medical advice. Medical disclaimer.