TB-500 by prescription in the US

TB-500 is a short chain of seven amino acids, the building blocks of protein. It copies one small piece of thymosin beta-4, a protein the human body makes. All TB-500 sold today is made in a lab.

You may also see it called thymosin beta-4 fragment, Tβ4 17-23, TB-4 fragment or LKKTETQ. The form named in the HHS policy is TB-500 acetate.

TB-500 is not the same as thymosin beta-4. Many websites use the two names as if they were one. The FDA says they are different substances, and most human research used the full protein.

TB-500 is a common name, not an official drug name. The FDA says it has found different salts and related compounds sold under the same name. That is one reason to ask a pharmacy exactly what is in the vial.

It first appeared in 2011 as a veterinary product for racehorses and racing greyhounds. It is not FDA approved for any use. The FDA found no approved TB-500 medicine in Canada, Australia, the UK or the European Union.

Compounding is when a licensed pharmacy makes a drug for one patient on a prescription. Under federal law, a 503A pharmacy can usually only use ingredients that pass one of three tests. The ingredient is part of a drug the FDA has approved, has a USP monograph, or is on the FDA's 503A bulks list. TB-500 passes none of them.

From September 29, 2023 to April 22, 2026, the FDA kept TB-500 on its Category 2 list. That list flags ingredients that may pose serious safety risks. TB-500 came off it after the group that nominated it withdrew. HHS says neither step changed its legal status.

On July 23, 2026, the FDA's compounding advisory committee discussed TB-500. FDA staff advised against adding it to the 503A bulks list, in part because they found no human data. HHS says the committee still voted in favor. The vote is advice only, and the FDA has not made a final decision.

On October 30, 2026, HHS published a notice in the Federal Register, FR Doc 2026-22192. HHS Secretary Robert F. Kennedy, Jr. signed it. The policy it announces lists six peptides, and TB-500 is one of them.

HHS says it does not intend to take enforcement action against a state-licensed pharmacy, federal facility or licensed doctor that compounds TB-500 under the policy's conditions. This lasts until a final FDA rule decides whether TB-500 goes on the 503A bulks list.

This is not FDA approval and it is not a final rule. The notice calls the policy a draft and takes public comments for two weeks. HHS says the policy is not binding and may be revisited if a safety or quality problem appears.

The pharmacy needs a valid prescription for you by name. It cannot sell TB-500 to anyone without one. Products sold as "research use only" are outside the policy. HHS says it wants to move people away from those products.

For TB-500, the policy covers only injection under the skin or into a muscle. Capsules, tablets, nasal sprays and creams are not covered.

Each product may contain only one active ingredient. Blends, such as TB-500 mixed with BPC-157, fall outside the policy. If a device comes in the pack, it must be an FDA-cleared syringe.

The raw peptide must come from a maker registered with the FDA. Each lot needs a certificate of analysis that names the maker and its site. It must show tests for identity, purity, strength and contaminants such as endotoxins and heavy metals.

The label must say: "This is a compounded drug product. Not for resale." The pharmacy must report serious side effects and quality problems to the FDA through MedWatch.

Start with a visit, in person or by video, with a licensed prescriber. They should review your health history, your current medicines and why you want TB-500. They decide whether a prescription is right for you.

The prescriber must be licensed in the state where you are at the time of the visit. The Federation of State Medical Boards says state medical boards require this for telehealth, though some states allow narrow exceptions. Ask which states they are licensed in before you book.

The prescription then goes to a state-licensed 503A compounding pharmacy. The pharmacy makes the product for you and ships it or has it ready to pick up. Ask whether the pharmacy is licensed in your state, and check on your state board of pharmacy website.

Not every provider serves every state, so check before you pay. In a proper prescription route, a prescriber approves you before you can check out for the peptide. A site that sells TB-500 with no prescription is not using this route.

Human evidence for TB-500 itself is missing. In its July 2026 review, the FDA found no published study in which TB-500 was given to people. It found no human data on safety, on how the body handles it, or on whether it works.

TB-500 was put forward for wound healing. The FDA found no evidence that it helps wounds in people. Online claims about tendons, muscles, hair or the heart are not backed by human trials of TB-500.

The full thymosin beta-4 protein has been tested in people. A small study gave it into a vein to healthy volunteers, and side effects were infrequent and mild or moderate. Other trials tested it on skin ulcers and, as eye drops, for dry eye.

Those results are for the full protein, not for TB-500. HHS points to the full protein's safety record and says the TB-500 fragment breaks down quickly in human blood serum. Neither point shows that TB-500 works in people.

If a provider tells you TB-500 is proven to heal injuries, that is not what the evidence shows. Ask them what study they mean.

Because no one has studied TB-500 in people, its risks are unknown. The FDA's concerns are immune reactions to an injected peptide, peptide clumping and impurities. HHS says these concerns are based on theory, not on harm seen in patients.

Lab and animal studies link the natural thymosin beta-4 protein to the spread of some cancers. No one knows whether TB-500 carries that risk. Tell your prescriber if you have or have had cancer. There is also no safety data in pregnancy or breastfeeding.

Ask your prescriber: Are you licensed in my state? What is the reason for this prescription, and what are the other options? How do I report a side effect?

Ask the pharmacy: Are you a 503A pharmacy licensed in my state? Is this TB-500 acetate with no other active ingredient? Can I see the certificate of analysis for my lot, with the maker's name and site?

If you have a side effect, tell your prescriber. You can also report it to the FDA through MedWatch.

We checked 250 US sellers of the six peptides in the HHS policy. 98 ranked providers list TB-500. Another 15 list it but did not make our ranking. 9 sellers offer it with no prescription check, and we do not rank them.

We score each provider on public evidence. That includes state licenses, a prescriber check before checkout, certificates of analysis and whether prices are public. Providers that sell blends lose points, because the policy covers one peptide per product.

What ranked providers charge: $165 to $250 a month, for the 3 of 8 that post a price and sell by the month. We leave out blend prices, such as TB-500 with BPC-157, because the policy does not cover blends. Check what each price covers.

Our research is from October 29, 2026. Prices, states served and policies change, so confirm the details with the provider before you pay.