More than anti-ageing: the retinol-alternative Chios mastic as a comprehensive approach for skin & scalp

This double-blind, placebo-controlled study involved a total of 44 (Asian, female) volunteers, aged 30 to 52 years (mean age: 38.3 y). Participants applied either an emulsion containing 2 % mastic active ingredient or a placebo emulsion twice daily to the face for 28 days. The parameter was impure skin (blackheads and microcysts).

The comedogenic potential was assessed by a clinician through the count of impurities across four facial zones: forehead, temples, cheeks, and chin. Visual changes were documented using macrophotographs (Nikon D80). At the end of the study, participants completed a self-evaluation questionnaire to assess perceived efficacy.

14-day clinical study on the efficacy of Chios mastic on sebum and skin hydration

This randomized, placebo-controlled half-face study was done with 23 volunteers (Asian, female) aged 21 to 48 years (mean age: 28.3 y) having oily skin and impurities. They applied a cream containing 2 % mastic active ingredient or a placebo twice daily for 14 days. Measured parameters on day 0, 7 and 14 were sebum output (Sebumeter® SM810) measured on the forehead, skin hydration (Corneometer® CM825) measured in the cheek region, and standardized facial photography (VISIA® CR).

28-day clinical study on the anti-ageing efficacy of mastic active ingredient

This randomized, placebo-controlled study involved 18 volunteers (Caucasian, female) aged 42 to 70 years (mean age: 57 y). They applied a cream containing 2 % mastic active ingredient or a placebo to one half of the face and the inner sides of each forearm twice daily for 28 days. The measured parameters were skin elasticity on the face (Cutometer® dual MPA 580, Courage + Khazaka, Germany) and density on the forearms using the Dermalab® Ultrasound system (Cortex Technology, Denmark).

28-day clinical study on the scalp-care efficacy of mastic active ingredient

This randomized, placebo-controlled trial included a total of 42 volunteers (Caucasian, female & male), aged 18 to 68 years (mean age: 46.5 y), all with oily scalp and visible dandruff. Volunteers were split into two groups and applied either a leave-on serum with 1 % mastic active ingredient or a placebo serum once daily to the entire scalp and massaged in thoroughly. The parameters were visible scalp dandruff (Aramo® ASW 300F system, 60 x magnification) and Malassezia occurrence (microbiota samples collected from the neck using sterile swabs). Swabs were streaked onto plates (ChromAgar medium) and incubated for 72 h at 30-37±1 °C under aerobic atmosphere. Grown colonies were transferred to Columbia Agar and, after microscopic preparation (Gram staining), analysed through biochemical and enzymatic tests to identify and quantify microbial strains. Malassezia was not present in all participants: it was detected in 12 individuals in the group using mastic active ingredient and in 14 individuals in the placebo group. Microbiota analysis was therefore conducted on these 26 volunteers. Dandruff severity was quantified using numeric values derived from the macrophotographs.

Results showed that after 28 days of treatment with mastic active ingredient, a clear improvement in impure skin was observed: the number of impurities (blackheads and microcysts) decreased significantly (Figure 2).

A visible improvement of impure skin was achieved after 28 days of treatment with mastic active ingredient (Figure 3).

Reduced sebum production and improved skin hydration

Another clinical study evaluated the effectiveness of mastic in reducing sebum production and improving hydration. Results indicated that after 14 days of treatment with mastic active ingredient, a significant improvement in these key skin parameters was observed.

Skin hydration showed a significant increase at both time points – day 7 and day 14 – compared to baseline and placebo, demonstrating the moisturizing benefits of mastic active ingredient (Figure 4, left). On the other hand, sebum levels were significantly reduced after both 7 and 14 days of treatment compared to baseline and placebo, indicating effective sebum-regulating properties (Figure 4, right). Moreover, the visible improvement of skin condition in terms of sebum reduction was clearly visible after 2 weeks of treatment (Figure 5).

After 28 days of treatment with mastic active ingredient, a significant improvement of skin elasticity of 20.4 % compared to initial conditions was observed in the face of the volunteers. In addition, skin density measured at the forearm improved significantly by 13.8 % after the treatment with mastic active ingredient (Figure 6, left). Ultrasound measurements clearly showed visible improvements in skin density (Figure 6, right).

After 28 days of treatment, the scalp serum containing 1 % mastic active ingredient demonstrated significant efficacy in improving scalp condition. Dandruff levels were reduced by 50.4 % compared to baseline, while the placebo group showed a reduction of only 27.8 % (Figure 7, left). Microbiological analysis further supported these findings. The occurrence of Malassezia colonies was significantly reduced by 85.3 % in the mastic group, compared to a 25 % reduction with the placebo treatment (Figure 7, right).

The underlying mechanism of action, inhibition of CYP26A1, sets mastic active ingredient apart from conventional retinoid alternatives. By preventing the enzymatic degradation of retinoic acid, mastic increases endogenous levels of this key metabolite, thereby enhancing its biological activity without the need for external application. This may lead to normalized cell turnover, reduced inflammation, and strengthened barrier function, benefits that are crucial for both skin and scalp health.

These findings emphasize the broad applicability and scientific significance of mastic active ingredient. It effectively combats surface-level issues like oiliness, dryness, and dandruff while simultaneously addressing their underlying causes through a gentle, retinoid-boosting mechanism. The clinical data presented in this study confirm its comprehensive performance, positioning Chios mastic active ingredient as an innovative, plant-derived alternative to conventional retinoids. Its capacity to improve diverse skin and scalp conditions makes it a uniquely integrative active component in contemporary skincare formulations. Further studies are currently underway to explore the broader cosmetic potential of mastic active ingredient, including its anti-aging effects and benefits for scalp care.