PTD-DBM

Human data: none for treatment, two observational findings

There is no published human trial of PTD-DBM. The human element in this literature is observational. In the 2015 wound paper, 4 mm biopsies were taken from the wound margins of five patients at 0, 7, 28 and 84 days after excision of cutaneous melanoma, under an institutional review board approval at Severance Hospital in Seoul, and CXXC5 protein was lower in epidermal keratinocytes and dermal fibroblasts of acute wounds while beta-catenin rose (PMID: 26056233). In the 2017 hair paper, CXXC5 was raised in miniaturized hair follicles and arrector pili muscles in balding human scalp, and CXXC5 and beta-catenin ran inversely to each other in haired and bald scalp (PMID: 28595998; PMID: 28967390). Both are expression measurements in tissue, not treatment of patients.

Mouse wound healing, 2015 (PMID: 26056233)

Choi's group created full-thickness wounds 1.5 cm across on the backs of 7-week-old male C3H mice and treated them daily with topical PTD-DBM at 100 micromolar alone, valproic acid at 500 millimolar alone, the two in combination, or epidermal growth factor at 100 micromolar as a positive control, with a phosphate-buffered saline vehicle group, using 16 mice per group. PTD-DBM raised beta-catenin in the wound. PTD-DBM alone and valproic acid alone accelerated closure about as efficiently as epidermal growth factor, and the combination accelerated it further. In a parallel genetic arm, Cxxc5-null mice closed the same wounds 16 to about 32 percent faster than wild-type littermates during the proliferative phase, with more collagen by hydroxyproline assay and by three collagen stains, and more keratin 14, collagen I and proliferating cell nuclear antigen. Oral bosentan reversed much of that, placing endothelin-1 in the mechanism.

Mouse hair regrowth and follicle neogenesis, 2017 (PMID: 28595998)

This is the paper the hair claims rest on. In human hair follicle dermal papilla cells, overexpression and silencing of CXXC5 showed that CXXC5 suppresses alkaline phosphatase activity and cell proliferation through Dvl-1. In mice, deleting Cxxc5 accelerated hair regrowth, and valproic acid in those mice added more. Disrupting the CXXC5-Dishevelled interaction with the competitor peptide activated Wnt/beta-catenin signalling and accelerated hair regrowth and wound-induced hair follicle neogenesis, with raised beta-catenin, alkaline phosphatase, proliferating cell nuclear antigen and, in the neogenesis model, Fgf9 and keratin 17 (PMID: 28595998; PMID: 28967390). The published abstract does not give group sizes, and the paper is not open access, so no sample size is quoted here.

Mouse hair loss driven by prostaglandin D2 and dihydrotestosterone, 2023 (PMID: 36831222)

The methods in this open-access paper give the clearest picture of how the peptide was used on hair. For regrowth, the backs of 7-week-old C57BL/6N mice were depilated and treated topically with 300 microlitres of either 10 micrograms of prostaglandin D2 or 10 millimolar PTD-DBM every other day from day 8 to day 12 or 20, and regrown hair was weighed and measured. For neogenesis, 3-week-old mice received 1 square centimetre full-thickness wounds and 20 microlitres of the same agents topically each day from day 7 to day 17 or 25. Prostaglandin D2 suppressed both regrowth and neogenesis, and PTD-DBM or deletion of Cxxc5 restored them. The paper also reports that dihydrotestosterone acts through prostaglandin D2 in this chain and that the small molecule KY19382, applied at 2 millimolar daily for 42 days, moved more follicles into anagen in dihydrotestosterone-treated mice.

Scar-reduction patch, 2023 (PMID: 36854308)

An adhesive pyrogallol-functionalized hyaluronic acid patch loaded with PTD-DBM, with or without valproic acid, reduced scar formation during wound healing in mice, lowered alpha-smooth muscle actin, raised the stem-cell markers CD105 and Nestin, and raised collagen III.

Cell and structural groundwork

CXXC5 was first described as a Dishevelled-interacting Wnt inhibitor in rat neural stem cells (PMID: 19001364) and as the Wilms tumour 1 target WID in kidney development, where it inhibited Wnt signalling through its CXXC and Dvl-binding domains and where knocking it down disturbed zebrafish kidney development (PMID: 20220130). Choi's group established the negative feedback loop in osteoblast differentiation, where a competitor peptide blocking the Dvl-CXXC5 interaction activated the pathway and thickened cultured mouse calvariae (PMID: 25633194). The crystal structure of the mouse Dvl1 PDZ domain with modelling of CXXC5 binding came from the same university (PMID: 27932247).

What the reviews say, and what they do not show

Two 2025 reviews place the Dvl-CXXC5 interaction among the next targets for androgenetic alopecia (PMID: 40924915; PMID: 40497955). One of them describes efficacy for peptides such as PTD-DBM in clinical terms (PMID: 40497955), but the primary reports behind that sentence are the mouse and cell studies above, and a search of ClinicalTrials.gov on 20 October 2026 found no registered trial of PTD-DBM. A reader should treat the review language as a summary of preclinical promise.

There is no human safety data on PTD-DBM, because there is no published human study of it. What exists is what the authors measured in their own mouse and cell experiments.

Cancer markers checked by the authors. Because Wnt/beta-catenin activation is involved in carcinogenesis and because both acute and chronic wounds carry a raised risk of basal cell carcinoma, the 2015 paper checked whether the peptide pushed oncogenic markers. PTD-DBM did not raise c-Myc or cyclin D1 in cells or in mice, and wounds treated with the peptide and examined six months after wounding showed no abnormal skin histology and no rise in either marker, in three mice per group (PMID: 26056233). Two markers in one model is a narrow check, not a carcinogenicity study.

Fibrosis is the mechanism-level concern. The same signalling the peptide switches on drives myofibroblast differentiation and collagen production, and the authors note that the Wnt/beta-catenin pathway is aberrantly active in human fibrotic disease. In their own cell work PTD-DBM raised alpha-smooth muscle actin and collagen I about as strongly as Wnt3a or transforming growth factor beta, the mediators of dermal fibrosis (PMID: 26056233). A later paper from the group loaded the peptide into a hyaluronic acid patch specifically to reduce scar formation, which indicates the group treats scarring as a real variable rather than a solved one (PMID: 36854308).

Effects outside skin in gene-deleted animals. The animals that model the peptide's action by lacking CXXC5 are not normal elsewhere. Cxxc5-deficient mice had raised bone mineral density (PMID: 25633194), delayed growth plate senescence with longer tibias when the interaction was blocked with a small molecule in adolescent mice (PMID: 30971423), and resistance to diet-induced metabolic dysregulation (PMID: 35384342). Those are reasons to expect a systemically delivered CXXC5 blocker to do more than one thing, not findings about topical peptide use.

The partner drug carries its own profile. Most of the strong results pair PTD-DBM with valproic acid. The commentary on the 2017 hair paper points out that valproic acid inhibits histone deacetylase as well as glycogen synthase kinase 3 beta, so part of the combined effect may be epigenetic rather than Wnt-specific (PMID: 28967390). Valproic acid has a large human safety literature of its own that has nothing to do with this peptide.

No dermal irritation study, no repeat-dose toxicity study, no reproductive data and no human exposure data on PTD-DBM were found.