New research published in the British Journal of Dermatology has found that applying a common food additive to hair follicles can activate taste receptors and prevent hair growth in lab tests.

While taste receptors are usually associated with tastebuds in the mouth, they are found throughout the body and perform various functions. Although taste receptors have previously been found in the skin, their function is unknown.

In this study, researchers from the USA and Germany found that human scalp follicles, the tiny biofactories that produce hair, have a bitter taste receptor called TAS2R4. When stimulated with a natural, stevia-like sweetener, rebaudioside A (or Reb-A), the taste receptor sends signals to the follicles that suppress hair growth.

The signals from TAS2R4 do two things; reduce cell division in the hair follicle and start production of a growth factor, TGF-β2, known to stop hair growth.

Professor John McGrath, Editor-in-Chief of the British Journal of Dermatology, said:

“Activating taste receptors in hair follicles with natural sweetener to prevent unwanted hair growth is not a combination of words I necessarily expected to see before reading this research, and yet here we are. We don’t know for sure that activating these taste receptors in hair follicles could reduce hair growth in people – but it’s the type of research that could one day lead to a new type of hair removal product.

“The concept is that activating the receptors alters the way a hair cycles through its growth phases, promoting what is known as ‘apoptosis’, where the hair follicles start to die, stopping hair growth in its tracks.

“So far, the research has been conducted on donated human scalp skin from hair transplant and facelift patients – an important step will be to see if the findings can be repeated in clinical trials on humans rather than just isolated hair follicles.”

The researchers carefully isolated healthy hair follicles from donated scalp skin, keeping them functioning in a controlled environment, designed to prevent other sources of stimulation which could impact the research. The follicles were then treated with either a high dose of Reb-A, which is known to activate TAS2R4, or a control substance every other day for 6 days.

By analysing hair follicles donated by males and females separately, the researchers confirmed that Reb-A works regardless of sex.

The researchers also tested whether carefully blocking TAS2R4 signals would stop the sweetener from preventing hair growth – and it did. This provides further evidence that Reb-A is preventing hair growth by activating TAS2R4, as described by the researchers, rather than by some other unforeseen mechanism.

Professor Ralf Paus of the University of Miami and lead author of the study said:

“Despite the name, and their historical association with tastebuds, taste receptors crop up in unexpected places. These findings identify specific taste receptors in human hair follicles, demonstrate they are active, and that they can be triggered to control hair growth. Given that, paradoxically, a sweetener can tickle bitter taste receptors so that they send signals which halt hair growth makes one wonder: Is this ‘the bitter-sweet end of unwanted hair?

“Beyond the obvious clinical relevance of our findings, this line of research also poses two intriguing questions. We know that these taste receptors can be found in many parts of the body, such as the airways and the gut. If we can regulate TGF-β2, a powerful growth factor, simply by triggering taste receptor signalling, what other processes could be controlled in this way? And since, in real life, we don’t have much natural sweeteners floating through our tissues: which substances do these taste receptors recognize 24/7 in the real life of a hair follicle?”

-ENDS-

Notes to Editors

For more information, please contact the media team: comms@bad.org.uk, 07769000415.

Study Details

Title: Human scalp hair follicles can “taste”: Chemosensory signalling via the bitter taste receptor, TAS2R4, inhibits hair growth ex vivo

Authors: Gherardini, Jennifer; CUTANEON-Skin & Hair Innovation GmbH

Rouille, Thomas; QIMA Life Sciences-QIMA Monasterium GmbH

Stone, Rivka C.; University of Miami Miller School of Medicine, Dr. Phillip Frost Dept. of Dermatology & Cutaneous Surgery

Fehrholz, Markus; QIMA Life Sciences-QIMA Monasterium GmbH

Funk, Wolfgang; Clinic for Plastic, Aesthetic and Reconstructive Surgery Dr. Dr. Funk

Rodríguez-Feliz, Jose; Skin & Hair, Plastic Surgery Dr. Rodríguez-Feliz

Bauman, Alan J.; Bauman Medical Group

Bíró, Tamás; CUTANEON-Skin & Hair Innovation GmbH

Chéret, Jérémy; CUTANEON-Skin & Hair Innovation GmbH; University of Miami Miller School of Medicine, Dr. Phillip Frost Dept. of Dermatology & Cutaneous Surgery

Paus, Ralf; CUTANEON – Skin & Hair Innovations GmbH; University of Miami Miller School of Medicine, Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery

DOI: https://doi.org/10.1093/bjd/ljaf060

About the BAD

The British Association of Dermatologists (BAD) is the professional membership body for dermatologists in the UK. Founded in 1920, the BAD is a registered charity representing over 2,400 members, dedicated to medical education, professional practice and standards, and research in dermatology.

For further information about the charity, visit www.bad.org.uk.

About the BJD

The British Journal of Dermatology (BJD) is a top-ranked international dermatology journal, publishing the highest-quality research to advance the understanding and management of skin disease to improve patient outcomes. The BJD is one of the journals of the British Association of Dermatologists, the professional membership body for dermatologists in the UK.

https://academic.oup.com/bjd