Electric comb for hair regrowth restores fur in mice

An electric comb for hair regrowth has produced a striking result in mice: after just one month of treatment, fur had returned across almost the entire treated skin area. Mice receiving topical minoxidil, one of the most widely used hair-loss medications, achieved approximately 70% coverage.

The device, called Detangle, was developed by a research team led by scientists at Beihang University in Beijing. Their findings appeared in Nature Communications on November 3, 2026.

At first glance, Detangle looks like an ordinary hairbrush. Its teeth, however, contain miniature electrodes and compartments holding molecules designed to influence hair follicle activity.

As the comb moves across the skin, it generates a localized electric field that simultaneously stimulates follicles and helps transport therapeutic molecules into their cells.

The underlying challenge is familiar to drug-delivery researchers: hair follicles lie beneath the skin's protective surface, making them difficult targets for many topical treatments.

Getting treatment to the follicle

Androgenetic alopecia, commonly known as pattern hair loss, involves the progressive miniaturization of susceptible hair follicles.

Genetics plays a major role, but one important biological driver is dihydrotestosterone (DHT), a hormone produced from testosterone by the enzyme 5-alpha-reductase.

In susceptible follicles, DHT gradually shortens the hair growth phase and contributes to follicular miniaturization. Hair becomes finer, shorter, and eventually less visible.

Two familiar treatments address different aspects of this process.

Finasteride reduces DHT production by inhibiting 5-alpha-reductase. Oral treatment can be effective, but its systemic action comes with potential adverse effects.

Topical minoxidil supports hair growth through a different mechanism, although responses vary and the skin barrier can limit the delivery of certain substances.

The Beihang team approached the problem from an engineering perspective. Rather than relying on a drug diffusing through the skin, they designed a device capable of helping biologically active molecules reach follicular cells.

An electric field with two purposes

Detangle uses electrodes positioned at different heights along its comb teeth.

This unusual geometry concentrates the electric field deeper into the follicular region. According to the researchers, the field penetrated approximately nine times deeper than that produced by conventional electrodes applied externally to the skin under their experimental conditions.

The pulses serve two functions.

They provide localized electrical stimulation and temporarily increase cell membrane permeability, facilitating the delivery of large molecules into cells.

This second process is related to electroporation, in which a controlled electric field makes cellular membranes more permeable for a short period.

The researchers combined this delivery mechanism with two genetic payloads.

One was a plasmid encoding VEGF-A, a protein that promotes blood vessel formation. Increasing vascular support around hair follicles may help create conditions favorable for hair growth.

The other was a small interfering RNA, or siRNA, targeting SRD5A2, the gene encoding type 2 steroid 5-alpha-reductase.

By reducing expression of this enzyme, the siRNA is intended to lower local DHT production and counteract one of the biological processes associated with follicular miniaturization.

The system therefore targets both the environment supporting follicle growth and a hormonal pathway involved in pattern hair loss.

Importantly, this is more than an electrically powered comb. Its performance depends on a combination of bioelectronic stimulation and molecular delivery.

What happened over 28 days?

The researchers tested Detangle in mice with experimentally induced hair loss designed to model aspects of androgenetic alopecia.

The animals received treatments approximately every three days over a 28-day period. Other groups received established hair-loss treatments, including minoxidil and finasteride.

By the end of the experiment, fur had regrown across nearly 100% of the evaluated skin area in the Detangle group. The corresponding figure for topical minoxidil was approximately 70%.

The researchers also reported changes consistent with improved vascularization and increased follicle numbers in treated skin.

Those results suggest that the treatment influenced more than the visible appearance of the fur.

But the headline number requires careful interpretation.

Nearly 100% regrowth refers to coverage of the experimental skin area. It does not establish that every original follicle was restored or that the tissue returned completely to its previous biological state.

The distinction matters even more when considering human hair loss.

Pattern baldness in people is a chronic condition that typically develops over years. The mouse model used in this study reproduced selected aspects of that condition over a much shorter period.

The researchers did not conduct a clinical trial in humans. The study also did not establish how long the new hair would persist after treatment stopped or whether repeated use would be safe and effective on the human scalp.

The genetic payloads add another layer of complexity. A device delivering a VEGF-A plasmid and gene-silencing RNA would require a very different level of evaluation from an ordinary cosmetic hairbrush.

Nevertheless, the underlying delivery strategy has implications beyond alopecia.

Moving large biological molecules through the skin and into specific cell populations is a major challenge across dermatology and biomedical engineering.

Detangle offers an experimental demonstration of a way to combine physical stimulation with targeted molecular delivery in a device designed for a familiar daily action.

What the researchers have established is not a cure for human baldness, but a proof of concept: a comb-shaped bioelectronic system can transport genetic material into follicular cells and substantially improve hair regrowth in an experimental mouse model.