A Drug That Regrows Teeth Moves Closer to Reality

For generations, a lost adult tooth has meant one outcome: a prosthetic replacement, whether an implant, a bridge, or a denture. A research program in Japan is now testing whether that assumption can be changed. The experimental drug TRG035, developed by the biotech company Toregem BioPharma, works by blocking a protein called USAG-1.

The approach is rooted in the concept that humans retain vestigial tooth buds capable of producing a third set of teeth, but that USAG-1 normally prevents these from developing.

By suppressing that protein, researchers hope to switch those dormant buds back on.

The drug began human testing at Kyoto University Hospital in October 2024. Phase I trials involved healthy adults with at least one missing tooth and were designed to assess safety. The trials concluded without serious adverse events.

That is an early and limited result — it does not confirm the drug can actually grow teeth — but it was enough to keep the research moving forward.

The drug also received orphan drug designation from Japan's Ministry of Health, Labour and Welfare for the treatment of severe congenital hypodontia, a rare condition in which people are born missing six or more permanent teeth.

In May 2026, Toregem announced a Pre-Series C financing round to support Phase II clinical trials of TRG035 in Japan and preparations for future clinical development in the United States.

TRG035 is now moving towards Phase II trials in patients with severe congenital hypodontia after securing that new funding.

For pediatric patients with severe hypodontia, the clinical stakes are significant, because implants cannot usually be placed until jaw growth is complete, meaning children may rely on removable dentures for years, with consequences for function, nutrition, and quality of life.

It is worth keeping expectations measured.

TRG035 remains experimental and has not yet been shown to regrow teeth in humans, and while researchers ultimately hope the approach could be used for adult patients with acquired tooth loss, that remains a longer-term goal.

The research team has suggested a target of having the medicine ready for general use around 2030, though that date should be treated as provisional, since TRG035 still needs Phase II efficacy data, further regulatory review, and approval before it could become available.

For now, the story is one of careful scientific progress rather than imminent clinical change.