A dissolving microneedle patch combining stevioside and minoxidil pushed hair follicles back into the growth phase in a mouse model of androgenetic alopecia, researchers report. The October 10, 2025 study, published in Advanced Healthcare Materials, used stevioside — a sweetener extracted from the Stevia plant — to solve a stubborn delivery problem that has limited minoxidil since its 1980s approval.

Why doesn't minoxidil work as well as it should?

Minoxidil remains one of the few topical drugs approved for pattern hair loss. It widens blood vessels and increases blood flow around the follicle, which extends the anagen phase and can spark new strands.

Two chemistry problems hold the drug back. Minoxidil dissolves poorly in water. It also struggles to pass through the stratum corneum, the skin's outermost layer.

That double barrier forces daily application for months before results appear. Even consistent users see variable outcomes, and adherence is widely cited as the biggest failure point in real-world use.

What did the stevioside patch actually do?

Co-corresponding author Lifeng Kang, PhD, of the University of Sydney, led the team. They loaded both stevioside and minoxidil into dissolvable microneedles — tiny polymer arrays that painlessly pierce the stratum corneum and dissolve underneath.

In the mouse alopecia model, the patch triggered follicles to re-enter the growth phase. New hair followed. Stevioside acted as a natural permeation enhancer, not as the active growth agent itself.

"Using stevioside to enhance minoxidil delivery represents a promising step toward more effective and natural treatments for hair loss, potentially benefiting millions worldwide," Kang said.

The full author list: Junying Zhang, Tianyu Shao, Hailiang Li, Luying Zhu, Lamyaa Albakr, Nial J. Wheate, Lifeng Kang, and Chungyong Wu. The paper sits at DOI 10.1002/adhm.202503575.

What's the underlying biology, and who is it for?

Androgenetic alopecia hits both sexes. Hair follicles become increasingly sensitive to dihydrotestosterone, or DHT — a hormone derived from testosterone. The follicles shrink. Strands grow shorter and finer. Growth eventually halts.

Men typically see a receding hairline or vertex thinning. Women usually see diffuse thinning across the part line. The biological mechanism is shared across presentations, even as the visible pattern diverges.

What could this change for clients and stylists?

Better skin delivery could mean:

• Less frequent application
• Lower cumulative dose
• Reduced irritation tied to overuse

That translates to fewer product touchpoints in a client's daily routine.

For chairside consultation, the takeaway is simple: a science story, not yet a shelf story. Clients asking about new options should hear that human trials still sit ahead. Standard minoxidil regimens — typically 5% solution or 5% foam, twice daily — remain the evidence-based baseline.

What sits between mice and a market launch?

Three gates:

• Human safety trials
• Scalable microneedle manufacturing
• Regulatory clearance for a combined formulation

Each typically takes years. For now, the data sits in a preclinical mouse model. The next milestone is likely a small-animal toxicology package that supports an investigational new drug filing — and from there, Phase I dosing work in healthy volunteers.