Investigating a New 4% Glycyrrhetinic Acid Treatment Approach for SSD

In a new pre- and postintervention study, researchers developed a novel 4% glycyrrhetinic acid complex scalp gel for mild to moderate scalp seborrheic dermatitis (SSD).¹ The product was assessed for efficacy using a short-contact application strategy.

Background

Current SSD therapies, with ingredients such as ketoconazole, ciclopirox olamine, zinc-pyrithione, or selenium sulfide, often take weeks to show improvement and may have limited efficacy or adverse effects.² Glycyrrhetinic acid, derived from licorice root, has well-documented anti-inflammatory, antimicrobial, antioxidant, and antiallergic properties.

Prior research from the authors found that a 6% glycyrrhetinic acid complex showed significant improvements after 2 weeks.³ However, this study uniquely evaluates its use in a gel formulation applied briefly for 10 minutes before rinsing, defined as "short-contact therapy." The evaluated gel was also augmented by Laurus nobilis (bay leaf) oil, known for its antibacterial and anti-inflammatory properties.

Methods and Materials

A total of 40 adult patients with mild to moderate SSD were enrolled and instructed to apply a thick layer of the gel daily for 2 weeks. Participants, all between the ages of 18 and 70, were recruited from the En Chu Kong Hospital in Taiwan between March 2024 and June 2024. The mean age of the cohort was 41.8 years: 25 were male and 15 were female.

Key clinical metrics, including the Adherent Scalp Flaking Score (ASFS) and Dermatology Life Quality Index (DLQI), were recorded at baseline, week 1, and week 2. The primary outcome was a reduction in ASFS, which assesses the severity of scalp flaking, while secondary outcomes included improvements in DLQI and patient satisfaction via a Treatment Satisfaction Questionnaire (TSQ). According to the ASFS, mild disease was defined as a score below 20, while moderate disease was considered to be between 21 and 40.

Results

The results showed a significant and rapid reduction in symptoms. The mean ASFS dropped by 50% at week 1 and 61.2% at week 2, both statistically significant improvements compared to baseline. Similarly, DLQI scores improved by 64.4% at week 1 and 66.9% at week 2. However, these differences between week 1 and week 2 were not statistically significant, suggesting that the majority of the improvement occurred early in treatment (p = 0.980). The TSQ showed a high satisfaction rate, with a mean score of 4.2 on a five-point Likert scale. Importantly, no adverse events were reported and none of the patients discontinued follow-up due to adverse reactions.

Subgroup analysis showed that patients who did not respond as well at week 1 (ASFS improved ≤ 50%) were more likely to have used scalp medications previously, suggesting possible interference with the gel’s effectiveness. Among the 13 nonresponders, 9 still demonstrated improvement, while 1 showed no change, and 3 experienced worsening in their scores. There were no significant differences in age, gender, or underlying health conditions between responders and nonresponders.

Limitations and Next Steps

Several limitations were noted, despite these promising findings. The sample size was relatively small and restricted to a single site, limiting generalizability. Severe SSD cases were not included, and the absence of a control group or comparison with standard treatments makes it difficult to definitively rank this gel’s efficacy. Moreover, the open-label design and short duration do not reflect real-world treatment adherence or long-term outcomes.

Overall, the steroid-sparing, anti-inflammatory, and antimicrobial properties of short-contact 4% glycyrrhetinic acid complex scalp gel offered rapid and substantial relief from SSD symptoms. Further large-scale, randomized controlled trials are needed to confirm its efficacy and position it within broader practice.

“By utilizing a novel gel containing herbal ingredients, we observed a rapid onset of therapeutic response, addressing a critical gap in early efficacy and offering an alternative to traditional steroid-based treatments,” the researchers concluded.

References

1. Wang, Chii-Shyan, Wang, Hsiao-Chi, Chen, Hsuan-Hsiang, Evaluation of a Novel Short-Contact Therapy With 4% Glycyrrhetinic Acid Complex Gel for Scalp Seborrheic Dermatitis: A Pre- and Postintervention Study, Dermatologic Therapy, 2025, 4298078, 7 pages, 2025. https://doi.org/10.1155/dth/4298078

2. Clark GW, Pope SM, Jaboori KA. Diagnosis and treatment of seborrheic dermatitis. Am Fam Physician. 2015;91(3):185-190.

3. Wang HC, Wang CS, Hsieh SC, Hung YT, Chen HH. Evaluation of a new-formula shampoo containing 6% glycyrrhetinic acid complex for scalp seborrheic dermatitis: A pilot study. J Cosmet Dermatol. 2022;21(8):3423-3430. doi:10.1111/jocd.14623