Stevia Extract Helps Minoxidil Penetrate Deeper, Regrowing Hair in Mice
Minoxidil has been the go-to topical treatment for hair loss for nearly four decades. Its limitations are just as familiar: twice-daily application, oily residue, scalp irritation, and a rebound effect when stopped. A team at the University of Sydney has approached these constraints from a different angle, not by replacing minoxidil, but by finding a way to get more of it where it needs to go.
The key ingredient: stevioside, a natural compound extracted from the stevia plant. Their findings were published in Advanced Healthcare Materials in 2025.
Why minoxidil underperforms
Minoxidil works by widening blood vessels around hair follicles and extending the anagen phase, the active growth stage of the hair cycle. The drug’s effectiveness is well-documented. But its poor water solubility and low skin permeability have always limited how much of each application actually reaches the follicle.
That constraint has real consequences. Because absorption is inefficient, the standard protocol requires applying the liquid twice daily to maintain therapeutic levels. Many users find this impractical over time, and discontinuation is common. When they stop, the hair gains reverse.
What stevioside does to the equation
Stevioside is a glycoside, a sugar-bound compound found in the stevia leaf. It is FDA-recognized as generally safe (GRAS) as a food additive and is widely used as a low-calorie sweetener. In this application, researchers used it as a penetration enhancer, a class of compounds that increase the rate at which drugs pass through biological barriers.
When combined with minoxidil in a dissolvable patch formulation, stevioside improved the drug’s water solubility and enhanced its ability to cross the skin barrier. The compound appears to facilitate more efficient delivery of minoxidil molecules into the deeper skin layers where hair follicles reside.
Results in the mouse model
The research team applied the stevioside-minoxidil patch to mice with androgenetic alopecia, the hormonal hair loss pattern that affects both men and women. The patch successfully stimulated hair follicles to re-enter the anagen phase, the growth stage of the hair cycle, resulting in new hair development. Lead researcher Dr. Lifeng Kang of the University of Sydney noted that the patch’s enhanced skin permeability was central to its therapeutic performance.
The study was authored by Zhang, Shao, Li, Zhu, Albakr, Wheate, Kang, and Wu.
The case for patch delivery
The transdermal patch format addresses more than just absorption. A patch that delivers a sustained dose throughout the day removes the twice-daily application burden and eliminates the oily, wet residue that causes scalp irritation in some users.
Adherence is a core challenge in any ongoing treatment. Minoxidil requires continuous use, and its benefits reverse on stopping. A format that makes daily use less burdensome has direct implications for treatment outcomes, not just convenience.
The caveats
This is mouse data. Mouse skin and follicle biology differ meaningfully from human scalp anatomy, and animal study results often do not translate directly to humans. No human clinical trials have been conducted, and the timeline to any commercial application remains unclear.
Stevioside’s safety profile as a food ingredient is well established. Its safety in topical patch form, and any systemic absorption concerns over long-term use, would need to be evaluated independently in human studies.
The broader trend in hair loss research is shifting toward delivery optimization. Rather than discovering new molecules, researchers are asking how to get proven ones to their targets more precisely. The stevioside patch sits squarely in that direction.