A cream made from a small protein eased skin pain after radiation, trial finds

Radiation after breast cancer surgery can leave the skin red, sore and itchy, a bit like a bad sunburn that lingers. Doctors call this radiation dermatitis. A team in South Korea tested whether a cream made from a small piece of a protein the body already makes could ease it [1].

Women who used the cream had less pain and better looking scars after 3 months than women who used a regular moisturising cream. Itching cleared up completely in every woman on the new cream, against half of the women on the regular cream [1].

It is early, though. Only 23 women finished the trial, and just 8 of them used the regular cream [1].

The trial was led by Min Ji Kim, with Il Jae Lee as senior author, in the plastic surgery department of Ajou University School of Medicine in Suwon. It was published in Aesthetic Plastic Surgery in October 2026. It was funded by the Korea Health Industry Development Institute, and the public record does not say whether the cream's maker had any role [1].

What is in the cream?

The cream holds NeoPep-S, a peptide. A peptide is a short chain of amino acids, the small building blocks of proteins. This one is cut from a larger protein called AIMP1, which the body already makes. In earlier lab work, a peptide from the same protein helped wounds heal [1][2].

That earlier work was in rats. In a 2022 study, a team at Seoul National University put the peptide on skin wounds in rats. At the higher of two strengths, wounds closed faster and showed fewer signs of inflammation. Those were animals, not people [2].

What did the trial find?

The women were having radiation after a mastectomy, an operation to remove the breast, and a reconstruction, surgery to rebuild it. For them, sore skin carries an extra risk. If the skin breaks down, an implant can be exposed and the rebuild can fail [1].

Thirty women joined between March 2022 and March 2023. Chance decided which cream each one used, with two women put on the new cream for every one on the regular cream. The skin was checked at the start, at 1 month and at 3 months [1].

The team measured four things. One was water loss through the skin, a sign of how well its outer barrier is working. Another was a scar score that rates things like colour, thickness and softness. Women also rated their itch and pain, and answered a survey on how satisfied they were [1].

The scar score was better on the new cream at 3 months, and pain was lower at both checks. Women on the new cream were also more satisfied with the information they got [1].

The barrier test told a weaker story. Water loss through the skin was about the same in both groups at 1 month. At 3 months the new cream only leaned ahead, which the authors call a trend. Even so, their summary describes lasting barrier recovery:

AIMP1-derived peptide (NeoPep-S)-containing cream is a beneficial adjunctive option for radiodermatitis management in post-mastectomy breast reconstruction patients, demonstrating sustained skin barrier recovery, superior scar and pain outcomes, and effective pruritus resolution.

Kim and colleagues, Aesthetic Plastic Surgery, 2026 [1]

In plain words, the authors see the cream as a useful extra for these women. But their own barrier numbers are weaker than that sentence, so the scar, pain and itch results carry most of the weight [1].

What does the trial not show?

An earlier trial gives a different reading. In 2025, a team at Chung-Ang University tested a cream with a peptide from the same protein in 15 women having breast radiation. Each woman put that cream on one side and a cream without the peptide on the other. The peptide side scored a little better, but the gap was too small to count. The authors wrote:

The AdP-containing cream did not prove to be more effective than the control cream without AdP in mitigating RD.

Han and colleagues, Supportive Care in Cancer, 2025 [3]

In plain words, in that trial the peptide cream did no better than the same cream without the peptide. Skin damage was milder than expected on both sides [3].

This new trial does not show that the cream prevents skin damage from radiation, or that it works for anyone outside this group of women. It was small, 7 of the 30 women did not finish, and it compared the cream with only one regular moisturiser [1].

The wider field is thin too. In 2025, ESTRO, a European society for cancer radiation treatment, published a guide from its radiation therapists' committee. It found a lack of strong evidence for any one cream or product [4].

So the result is a first step. In one small trial, a peptide cream eased pain and helped scars more than a regular cream. A larger trial would be needed to know whether that holds up [1].