Stevioside Microneedle Patches Could Boost Minoxidil for Androgenetic Alopecia

A widely used therapy for androgenetic alopecia (AGA) - the familiar pattern hair loss - may be improved by pairing it with stevioside, a natural sweetener taken from the stevia plant (Stevia rebaudiana).

Why minoxidil needs better delivery

Minoxidil is a common AGA treatment applied by rubbing it into the scalp. It is thought to work by boosting blood flow and re-energising hair follicles, but only a limited amount is absorbed through the skin. To tackle that, researchers have been testing different types of microneedle patches designed to help the drug penetrate further.

Stevioside microneedle patches and minoxidil

In a new study, teams in China and Australia combined microneedle patches with stevioside. The main rationale was that stevioside helps minoxidil dissolve far more effectively in water, which should allow a greater dose to pass beneath the skin and reach hair follicles.

To test the idea, the scientists used mice genetically engineered to lose hair. The results suggested the approach improved drug delivery into the skin and led to stronger regrowth.

"There is a significant increase in hair follicle transition to the growth phase, which resulted in 67.5 percent coverage of the treatment area by day 35," write the researchers in their paper.

"Collectively, the results highlight the potential of the stevioside microneedle delivery system for the treatment of AGA."

By comparison, mice given a conventional minoxidil solution showed regrowth across 25.7 percent of the area by day 35 - still a meaningful gain over minoxidil used alone. Hair growth also began roughly a week earlier with the stevioside microneedle method.

What the AGA results mean and what comes next

Although the findings are encouraging, the work was done on mouse hair rather than human hair. The researchers are continuing to refine both the microneedle delivery system and the minoxidil mixture to identify the most effective way to administer the treatment.

"The benefits and drawbacks of various technical methods, such as metal or soluble microneedles and sustained-release systems, should be evaluated in conjunction with specific clinical scenarios," write the researchers.

Before any human clinical trials can begin, the team says the method will need to be tested in larger animals. Only then can scientists judge how these microneedle patches might perform in people, while also assessing any side effects or other complications.

Long-term practicality will also have to be demonstrated. Standard minoxidil treatments must be used at least once a day, and while microneedle delivery could potentially alter that schedule, it still needs to be suitable for repeated, routine use.

"Using stevioside to enhance minoxidil delivery represents a promising step toward more effective and natural treatments for hair loss, potentially benefiting millions worldwide," says pharmacologist Lifeng Kang, from the University of Sydney in Australia.

The research has been published in Advanced Healthcare Materials.