Can plant‐derived phytochemicals provide symptom relief for hair loss?
It is known that hair growth disorders and hair loss can cause personal distress and affect well‐being. Gabriela Daniels, University of the Arts London and her Co-Workers have taken a critical look at the state of science and summarized it in a critical review article. This review provides a critical evaluation of the available evidence of their activity for hair benefit, excluding data obtained from animal tests, and offers recommendations on improving study validity and the robustness of data collection in pre‐clinical and clinical studies.
Number of clinical studies is low
In summary, whilst the range of phytochemicals proposed for treating hair loss is promising and growing, the number of clinical studies published so far is low and a common set of criteria for evaluating effective interventions with such preparations is generally lacking.
Over-reliance on clinician’s scales
Finally, when critically reviewing the reports of clinical studies with phytochemicals(topically and orally applied), the researchers conclude that there is an over-reliance on clinician’s scales and self-reported patient assessment. No histological data is presented although, some photographic evidence is published, and hence the investigators infer biological activity based on known properties of the plant extract being tested and/or in vitro data.
Combination of in vitro and/or ex vivo data would be better
In summary they recommend a combination of in vitro and/or ex vivo data with a well-designed clinical trial. Based on in vitro studies to date, it is also desirable that gender specific studies are conducted when androgen-related hair loss is targeted. The review has been accepted for publication in International Journal of Cosmetic Science https://doi.org/10.1111/ics.12554