How a natural sweetener improves hair loss treatment

Hair thinning and receding hairlines are common conditions with a specific name: androgenetic alopecia. This is a hormone-related form of inherited hair loss that affects an estimated 50 million men and 30 million women in the United States.

One research team thinks a simple tweak could make treatments work better. They used stevioside, a plant-derived sweet compound from Stevia rebaudiana leaves, to help minoxidil cross the scalp.

The experts then paired this with a dissolving microneedle patch – a patch made of microscopic, drug-filled tips that melt into skin.

How the hair patch works

The work comes from a team in Australia and China, including Dr. Lifeng Kang at the University of Sydney (US).

The patch dissolves into skin and releases minoxidil carried by stevioside micelles, tiny clusters of molecules that trap oil-loving drugs inside water-friendly shells.

The researchers first showed that stevioside can pull poorly soluble drugs into water at useful levels. For minoxidil, solubility rose to about 47 mg per milliliter, roughly an 18-fold jump over the drug alone.

They molded this solid dispersion into tiny needles that dissolve after pressing into skin. In lab tests across 24 hours, the patch delivered about 85 percent of its minoxidil load and left about 18 percent retained in skin.

In mice with testosterone-suppressed hair growth, the patch pushed follicles into the growth phase. By day 35, new hair covered about 67.5 percent of the treated area, outpacing a standard minoxidil solution.

Improving hair loss treatments

Topical minoxidil helps many people with pattern hair loss. It has approval for people of all genders, but it does not dissolve well in water and is absorbed through skin only in small amounts.

Only about 1.4 percent of a typical topical dose gets through intact skin. That low uptake helps explain why daily use over months is usually needed to see fuller strands.

Alcohol-based solutions can sting or irritate sensitive scalps. Foam products reduce that issue for some users, but they still need to rely on repeated applications.

A patch that holds minoxidil in solution and meters it directly into skin could reduce those hassles. It could also move more of the drug toward hair follicles.

How the patch helps hair

Microneedling itself can improve hair counts when added to minoxidil. A recent meta-analysis found that combined therapy increased hair numbers in comparison to using minoxidil alone across 12 to 24 weeks.

Different needle depths worked, with benefits seen at both less than 1 millimeter and greater than 1 millimeter depth. That suggests the microchannels, not just depth, matter for delivery.

Dissolving microneedles add a drug payload on top of the mechanical effect. They also avoid the waste and dosing variability that come with metal rollers.

Self-applied patches can standardize pressure and time on skin. That consistency makes it easier to test dose response in trials.

Help from a natural sweetener

Steviol glycosides are natural, plant-based compounds that give stevia its sweetness. They have a well-studied safety record as food additives in the European Union. 

Regulators set an ADI, or acceptable daily intake level that is considered safe over a lifetime, of 4 mg per kg body weight per day. Toxicology reviews did not find any carcinogenic or genotoxic signals.

Food safety does not automatically guarantee skin safety at higher local exposure. It does mean the starting material is familiar to regulators and widely consumed.

Chemically, stevioside has a fat-loving core and sugar groups that face water. In solution, multiple molecules can cluster into micelles that hide a water-hating drug in the center.

That behavior explains why the minoxidil solubility rose sharply in the study. It also helps the drug stay dissolved long enough to soak into the upper layers of skin.

Hair loss treatment results in mice

The mouse model used testosterone propionate, a synthetic hormone that suppresses hair growth, to hold follicles in a resting state.

With microneedle patch treatment, follicles shifted into growth and formed darker, deeper structures that were visible upon microscopic tissue examination.

Across one day of lab release testing, the hair patch delivered most of its dose and left a meaningful fraction inside skin. That retention matters because follicles sit in the skin, not on top of it.

In the animal study, the treated area reached 67.5 percent hair coverage by day 35. The standard solution group reached about 25.7 percent under the same conditions.

The authors also reported higher skin retention from the patch compared with the solution, despite a lower initial drug load. That pattern fits the idea that dissolved, targeted delivery beats excess drugs that sit on the surface.

Benefits of the hair patch

Daily drops or foam applications require discipline, and many people stop early. A patch that you apply less often could help with consistency and results.

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

What we still need to know

Mice are not people, and mouse hair cycles are shorter. Alopecia, a general term for hair loss of various causes, in these models comes from testosterone injections, not from decades of genes and aging.

Human scalps vary in sebum level, the natural oil that coats and protects skin, prevents inflammation, and enhances barrier function. Trials must show that a microneedle patch still works through sweat, styling products, and day-to-day movement.

Stevioside is safe in food at typical exposures, but a patch holds material against skin for hours. Developers should test for irritation and allergy in people with sensitive scalps.

A microneedle patch will also face questions about cost and disposal. If the device adds real gains in density or speed, those trade-offs might be acceptable.

Future research directions

Dose finding will matter, including how often to apply a patch. Researchers also need to learn whether patches help both early and advanced hair thinning.

Combination strategies will draw interest, but safety must lead. It is too early to assume that add-ons like finasteride, a hormone-blocking pill used for treating hair loss, would be appropriate.

Real-world use means sweat, sun, and hair-care routines. Any product must withstand these challenges without losing its grip or reducing the intended drug delivery.

The study is published in the journal Advanced Healthcare Materials.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–