How Does SCUBE3 Work on Hair Follicles Compared to Treatments Like Minoxidil or Finasteride?

Hair loss is a biological process that affects a significant portion of the global population, yet treatment options have remained largely unchanged for decades. Current therapies such as minoxidil and finasteride and emerging laboratory discoveries such as SCUBE3 each target a very different aspect of hair follicle biology. Comparing those mechanisms is the only way to judge whether a newer discovery represents progress or simply another experimental pathway.

This article summarises what the published research says about how SCUBE3 functions within hair follicles, and contrasts it with the mechanisms behind minoxidil and finasteride, in accessible language.

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How Hair Follicles Function and Why They Stop Producing Hair

Hair follicles are miniature organs embedded in the skin. Each follicle cycles through phases of growth, regression, and rest. The growth phase, known as anagen, can last several years and is when the hair shaft is actively produced. The regression phase, catagen, is a short transitional period when growth stops. The resting phase, telogen, ends with the hair shedding.

In androgenetic alopecia, commonly known as pattern hair loss, follicles gradually shrink in a process called miniaturization. This shrinkage is strongly influenced by dihydrotestosterone, or DHT, a hormone derived from testosterone. DHT binds to receptors in susceptible follicles, shortening the growth phase and producing thinner hairs over time until follicles become nearly inactive.

Most treatments attempt either to counteract DHT, support follicle health, or stimulate follicles to remain in the growth phase longer.

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SCUBE3: A Biological Growth Signal Within the Follicle

SCUBE3, short for Signal Peptide-CUB-EGF Domain-Containing Protein 3, is a protein naturally produced by cells within the hair follicle, particularly dermal papilla cells. These cells sit at the base of the follicle and act as its control center, regulating growth signals.

In the published mouse and cell work, dermal papilla cells that receive strong Hedgehog signalling shift into a highly activated state and secrete SCUBE3. The study reports that SCUBE3 then acts on neighbouring hair follicle stem and progenitor cells through TGF-β signalling, which is the pathway the authors identify as the growth instruction. Earlier popular write-ups that described SCUBE3 as a Wnt/β-catenin activator do not match the primary paper.

Unlike treatments that act on the follicle's environment or on hormones, SCUBE3 is described in that work as a signal that instructs follicles directly.

Scientific Evidence Behind SCUBE3's Role in Hair Regeneration

The primary study is Liu and colleagues, published in Developmental Cell in July 2022 by a group at the University of California, Irvine. It investigated how dermal papilla cells communicate with hair follicle stem cells, using cultured cells and live mouse models.

In that work, SCUBE3 was delivered into mouse skin where follicles were dormant, and the treated areas showed hair growth compared with untreated skin. The authors also report that SCUBE3 made transplanted human scalp follicles enter the growth phase sooner in mice; these follicles came from a single donor, with 6 treated and 5 control sites.

The limitations matter as much as the result. The great majority of the data came from mice, and while human follicles were used in a transplant model, there are no published human clinical trials of SCUBE3 for hair loss. That leaves real uncertainty about whether the effect will translate into a treatment for people.

Long-term safety in humans is also unknown. SCUBE3 is a growth-promoting signalling protein and it has never been given to people as a hair-loss therapy, so there is no human safety record to draw on.

Minoxidil: Enhancing the Follicle Environment Rather Than Regenerating It

Minoxidil was first developed as a medication for high blood pressure. Its hair growth effects were discovered when patients treated for blood pressure experienced increased body and scalp hair.

Minoxidil is generally described as working by widening blood vessels, a process called vasodilation, which increases blood flow to hair follicles. It is also reported to extend the anagen phase, allowing hair to grow longer before shedding. The full mechanism is still not settled in the literature.

Clinical trials dating back to the 1980s reported that topical minoxidil can produce moderate regrowth in some men and women with androgenetic alopecia. In published controlled studies, hair counts were measured using scalp photography and microscopic analysis, and participants using minoxidil showed higher hair density than those using placebo solutions.

However, minoxidil does not address the hormonal cause of follicle miniaturization, and its effects depend on continued use. Once treatment stops, newly grown hair typically sheds within months.

Finasteride: Blocking the Hormonal Trigger of Follicle Shrinkage

Finasteride targets the hormonal driver of pattern hair loss. It inhibits the enzyme 5-alpha-reductase, which converts testosterone into DHT. By lowering DHT levels in the scalp, finasteride is reported to slow further follicle miniaturization and, in some men, to partially reverse it.

Two one-year placebo-controlled trials in 1,553 men aged 18 to 41, of whom 1,215 continued for a second year (Kaufman and colleagues, 1998), reported that daily oral finasteride at 1 mg slowed hair loss and increased hair counts compared with placebo, assessed through standardized scalp photographs and dermatologist review.

Finasteride is a prescription medicine and carries reported side effects, including sexual dysfunction and mood changes in a minority of users. Some men have reported sexual problems, such as low sex drive and erection or ejaculation problems, that continued after they stopped finasteride, and the US, UK and EU product information all describe these reports. The US label also lists reports of depression and suicidal thoughts. The UK regulator (MHRA, May 2026) states that finasteride is associated with depression, suicidal thoughts and sexual dysfunction "which may persist after treatment is stopped". These come from voluntary reports, so how often this happens, and how far finasteride caused it, has not been established. The UK regulator (MHRA, May 2026) advises stopping finasteride 1 mg immediately and contacting a doctor if depression or suicidal thoughts develop. Finasteride must not be taken by women who are pregnant or who may become pregnant, because blocking DHT can affect the development of a male foetus; broken or crushed tablets should not be handled by them either.

Comparing the Biological Impact of SCUBE3, Minoxidil, and Finasteride

Set side by side, the three act at different points.

Minoxidil is described as improving the follicle's surrounding conditions rather than correcting the signalling that drives growth. Finasteride reduces the hormonal driver of miniaturization but depends on existing follicles retaining enough vitality to recover.

SCUBE3, in the laboratory work, acts on the regenerative signalling inside the follicle itself, pushing dormant follicles back into active growth in mice.

That has led researchers to suggest SCUBE3 could be relevant where follicles are dormant rather than merely shrinking.

Without human trials, this remains theoretical.

What Current Research Still Does Not Answer

Although SCUBE3 has generated interest, many questions remain unresolved. There is no established dose, no data on how often it would need to be given, and no evidence on whether repeatedly activating growth pathways has unintended consequences. There is no long-term human outcome data, and no head-to-head comparison with existing therapies in clinical settings.

By contrast, minoxidil and finasteride are supported by decades of clinical data, including large placebo-controlled trials, although most of those trials lasted one to two years.

A Critical Perspective on the Future of SCUBE3-Based Treatments

SCUBE3 represents a shift toward regenerative approaches rather than symptom management. The biological reasoning behind its mechanism is coherent, and the laboratory results are notable. Yet many promising animal studies have failed to produce effective human treatments.

Until controlled human trials report both safety and effectiveness, SCUBE3 is best regarded as an experimental laboratory finding rather than a confirmed breakthrough. It is not available as a medicine, and its long-term safety in humans is unknown. For androgenetic alopecia, topical minoxidil and oral finasteride remain the treatments the FDA has approved for that indication and the ones with the longest published follow-up; other drugs used for hair loss, such as low-dose oral minoxidil, are prescribed off-label, and JAK inhibitors are approved for alopecia areata rather than pattern hair loss.

Talk to a doctor or pharmacist before starting, changing or combining finasteride, minoxidil or any other hair-loss treatment. If you have thoughts of harming yourself, seek emergency help right away.

References

Liu, Y., Guerrero-Juarez, C. F., Xiao, F., Shettigar, N. U., Ramos, R., et al. (2022). Hedgehog signaling reprograms hair follicle niche fibroblasts to a hyper-activated state. Developmental Cell, 57(14), 1758–1775.e7. https://pubmed.ncbi.nlm.nih.gov/35777353/

Olsen, E. A., et al. (1987). Long-term follow-up of men with male pattern baldness treated with topical minoxidil. Journal of the American Academy of Dermatology, 16(3 Pt 2), 688–695. https://pubmed.ncbi.nlm.nih.gov/3549803/

Kaufman, K. D., Olsen, E. A., Whiting, D., Savin, R., DeVillez, R., Bergfeld, W., et al. (1998). Finasteride in the treatment of men with androgenetic alopecia. Journal of the American Academy of Dermatology, 39(4), 578–589. https://pubmed.ncbi.nlm.nih.gov/9777765/

National Library of Medicine. Hair loss overview. MedlinePlus. https://medlineplus.gov/hairloss.htm

U.S. Food and Drug Administration. Finasteride information (drug safety page). https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/finasteride-information

Propecia (finasteride) prescribing information, Organon. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6f904709-65aa-44ce-b144-b4c8a0416e36

Medicines and Healthcare products Regulatory Agency. (2026, May 11). Finasteride and dutasteride: updated safety warnings for psychiatric side effects and sexual dysfunction. Drug Safety Update. https://www.gov.uk/drug-safety-update/finasteride-and-dutasteride-updated-safety-warnings-for-psychiatric-side-effects-and-sexual-dysfunction