A guide to care questions / Human studies

What do the human studies show?

Match the study to the substance before matching its result to a claim.

Read each study with its own substance

No published study giving TB-500 to people turned up in FDA’s review.

The human research discussed here used thymosin beta-4, the whole protein made by the body, which is different from TB-500.

TB-500 is a short lab-made chain with an extra chemical part joined to one end.

FDA found no published studies testing TB-500 in people.

Its review also found no animal study of TB-500 testing a wound-healing benefit.

Full-length thymosin beta-4 is the longer protein.

Human research tested full-protein eye drops, skin gel and some injections.

Those full-protein studies do not show what TB-500 does.

In the 2015 Sosne–Ousler trial, 72 people received full-length thymosin beta-4 eye drops or dummy drops.

The full-protein study’s two main checks were eye discomfort and dye-test marks on the lower part of the eye’s clear front surface.

Neither check showed a clear difference between the full-protein drops and dummy drops.

Some other dry-eye checks improved with the full-protein drops, but they were not the study’s main tests.

ARISE-3 tested full-protein eye drops in 700 people and checked eye discomfort and the same dye-test marks.

Its posted results for both checks were similar for the full-protein drops and dummy drops.

These dry-eye results do not establish a benefit from injected TB-500 for an injury.

Small trials tested full-length thymosin beta-4 gel on leg sores and pressure sores.

At the end of 12 weeks, the share of closed sores was similar for the full-protein gel and the dummy gel.

The full-protein gel records gave counts of healed sores but no calculation of whether the differences could be due to chance.

Read that as limited evidence. It does not fill the gap for a different substance given by injection.