What Is Verteporfin, and Why Is It Being Studied for Hair Follicle Regeneration?

Hair loss research has historically focused on slowing follicle miniaturization rather than regenerating entirely new hair follicles. The recent scientific interest in verteporfin represents a shift toward a more ambitious question: can adult human skin heal in a way that restores complex structures such as hair follicles instead of forming scar tissue? To understand why verteporfin is being studied in this context, it is necessary to examine what the drug is, how it works at the cellular level, and what the available research actually demonstrates—without overstating findings that remain largely preclinical.

From Ophthalmology to Regeneration: What Verteporfin Actually Is

Verteporfin is a photosensitizing drug approved by the U.S. Food and Drug Administration in 2000 for the treatment of neovascular age-related macular degeneration. In this condition, abnormal blood vessels grow under the retina and leak fluid or blood, damaging vision. Verteporfin is administered intravenously and then activated with a specific wavelength of laser light directed into the eye. Once activated, it produces reactive oxygen species—chemically reactive molecules that damage the abnormal blood vessels while limiting broader tissue injury. The FDA approval documentation clearly defines verteporfin’s indication as ophthalmologic, not dermatologic or regenerative.

Importantly, verteporfin’s original mechanism involves photodynamic therapy, meaning it requires light activation to produce cytotoxic effects. However, later laboratory research discovered that verteporfin also inhibits a protein called Yes-associated protein, or YAP, even in the absence of light activation. YAP is part of the Hippo signaling pathway, a regulatory system inside cells that controls gene expression related to cell proliferation, tissue growth, and organ size.

The Hippo-YAP pathway functions as a molecular switchboard. When YAP is active, it enters the nucleus of the cell and binds to transcription factors, turning on genes associated with growth and fibrosis. Fibrosis refers to the formation of excess connective tissue, leading to scar formation. Scar tissue lacks normal skin structures such as hair follicles, sebaceous glands, and sweat glands. Therefore, inhibiting YAP has been proposed as a way to alter wound healing so that regeneration occurs instead of fibrosis.

The Central Scientific Question: Can Blocking YAP Prevent Scarring and Restore Hair Follicles?

The most cited study linking verteporfin to hair follicle regeneration was published in 2021 in Science Translational Medicine by Mascharak and colleagues. The study did not begin as a hair restoration trial. Instead, it investigated how specific fibroblasts—connective tissue cells responsible for producing collagen—contribute to scarring.

The researchers conducted experiments in adult mice. Full-thickness excisional wounds were created on the dorsal skin of the animals under controlled laboratory conditions. Verteporfin was locally applied to some wounds, while others served as untreated controls. The duration of the study extended several weeks, allowing complete wound closure and remodeling.

To evaluate outcomes, the investigators used histological analysis, meaning microscopic examination of tissue samples. They assessed collagen organization, presence of hair follicles, and expression of fibrosis-related genes. They also used lineage tracing techniques to determine whether fibroblasts expressing the gene Engrailed-1 were responsible for scar formation. The results showed that verteporfin-treated wounds had reduced Engrailed-1 activation, decreased fibrotic gene expression, and regeneration of skin appendages, including hair follicles.

While these findings were striking, they must be interpreted cautiously. The population studied consisted entirely of mice. Mouse skin differs significantly from human skin in thickness, hair density, immune response, and intrinsic regenerative capacity. Rodents naturally demonstrate a higher degree of regenerative healing than adult humans. Furthermore, verteporfin was applied immediately after acute wounding in a controlled setting. This does not replicate the chronic miniaturization process seen in androgenetic alopecia, where follicles shrink over years due to hormonal sensitivity to dihydrotestosterone.

Another limitation is that the study evaluated regeneration in the context of newly created wounds rather than bald scalp tissue. The distinction is critical. Regenerating follicles after acute injury is biologically different from reversing long-standing follicular miniaturization in pattern hair loss.

Mechanistic Evidence: What Cellular Studies Actually Show

Earlier research between 2014 and 2018 investigated verteporfin as a YAP inhibitor in cell culture and animal models. These studies typically involved human fibroblasts or mouse tissue samples. Researchers used polymerase chain reaction to measure gene expression changes and Western blotting to detect protein levels associated with fibrosis. These experiments lasted from several days to a few weeks and confirmed that verteporfin disrupts YAP-TEAD interactions, which are necessary for certain growth-related genes to activate.

However, these mechanistic studies did not evaluate cosmetic hair regrowth. They focused on molecular signaling and fibrotic activity. In scientific terms, they demonstrated pathway modulation, not clinical efficacy. The difference is essential. Demonstrating that a molecular pathway is inhibited does not automatically translate into safe, reproducible hair regeneration in humans.

Another important concern involves YAP’s role in cancer biology. Because YAP promotes cell proliferation, its dysregulation has been linked to tumor development in certain contexts. Long-term systemic or topical inhibition of YAP in humans has not been extensively studied. Any attempt to manipulate wound healing pathways must account for potential unintended consequences.

Human Evidence: What Is Not Yet Established

As of 2026, there are no large-scale, peer-reviewed clinical trials demonstrating that verteporfin regenerates hair follicles in humans with androgenetic alopecia. There are no randomized controlled trials evaluating hair density counts, dermoscopic measurements, or biopsy-confirmed follicle neogenesis in balding scalps treated with verteporfin.

This absence of human data is not a minor detail; it is the central limitation. The FDA approval of verteporfin applies exclusively to ophthalmologic use. Its dermatologic application remains experimental. Without controlled human trials that measure objective endpoints such as follicle counts per square centimeter, hair shaft diameter, and long-term safety outcomes, claims of hair follicle regeneration remain speculative.

For individuals experiencing hair loss, this means that verteporfin currently represents a research hypothesis rather than a validated therapy.

user experiences

Discussion within the Tressless community reflects both enthusiasm and skepticism. Users frequently reference the 2021 mouse study and discuss theoretical applications of verteporfin during hair transplantation or microneedling procedures. The central appeal is the possibility of true follicle neogenesis rather than maintenance of existing follicles.

At the same time, many community members emphasize that regenerative findings in mice have historically failed to translate into consistent human therapies. Some users note the lack of standardized dosing protocols and the absence of published human outcome data. The prevailing sentiment in community discussions is that verteporfin is scientifically intriguing but unproven, and that anecdotal experimentation cannot substitute for controlled trials.

These discussions highlight what we genuinely need to know: whether verteporfin can reproducibly regenerate human hair follicles, at what dose, with what safety profile, and under what clinical conditions. Until those data exist, verteporfin remains within the realm of experimental regenerative medicine.

Conclusion: What We Actually Know

Verteporfin is an FDA-approved drug for age-related macular degeneration that functions as a photosensitizer in ophthalmology. Independent laboratory research later revealed that it inhibits YAP, a key regulator in the Hippo signaling pathway associated with fibrosis and tissue repair. A 2021 mouse study demonstrated that YAP inhibition with verteporfin reduced scarring and enabled regeneration of hair follicles in wounded mice.

However, these findings are limited to animal models and controlled experimental wounds. There is currently no high-quality human clinical evidence demonstrating that verteporfin regenerates hair follicles in individuals with pattern hair loss. The mechanistic rationale is scientifically plausible, but clinical validation is absent.

Therefore, verteporfin is being studied for hair follicle regeneration because of its ability to modulate fibrosis-related signaling pathways. Whether that biological insight will translate into safe and effective human hair restoration remains an unanswered question requiring rigorous clinical investigation.

References

Food and Drug Administration. (2000). NDA 21-119: Visudyne (verteporfin) approval documentation. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/drugsatfda_docs/nda/2000/21-119_Visudyne.cfm

Mascharak, S., Talbott, H. E., Januszyk, M., Griffin, M., Chen, K., Davitt, M. F., et al. (2021). Preventing Engrailed-1 activation in fibroblasts yields wound regeneration without scarring. Science Translational Medicine, 13(585), eaba2374. Direct link: https://pubmed.ncbi.nlm.nih.gov/33637531

National Institutes of Health. (2023). Hippo signaling pathway overview. National Institutes of Health. https://www.ncbi.nlm.nih.gov/books/NBK555920/

Tressless Community. (2023–2025). Verteporfin discussion threads. https://tressless.com/search/verteporfin