03/06/2026
Contact dermatitis, either allergic or irritant, is a common skin disease associated with disruption in the skin barrier, which affects patients’ quality of life and impacts their work capacity. A recent clinical trial evaluated whether adding a special Calendula extract to a standard emollient cream could improve recovery of the skin barrier after experimentally induced irritant dermatitis. Calendula was studied because of its longstanding traditional dermatological use and growing experimental evidence suggesting that its topical use may support skin barrier repair via wound-healing and anti-inflammatory mechanisms.
The study included 20 healthy volunteers aged 22 to 35 years, of whom 17 were women and 3 were men. On each participant’s forearm, three separate test sites were created: one received no treatment (control), one received the emollient base alone (placebo), and one received the same emollient cream containing Calendula extract.
The active cream contained 1% of a supercritical CO₂ extract of Calendula officinalis, applied at approximately 5 mg/cm² twice daily for 8 days following experimentally induced irritant dermatitis. The base cream contained petrolatum, paraffin, cetearyl alcohol and propylene glycol, all recognised barrier-supportive ingredients.
After sodium lauryl sulfate-induced irritation (a synthetic detergent), all skin sites showed reduced hydration and increased trans-epidermal water loss (TEWL), confirming disruption of the skin barrier. However, the Calendula-treated sites recovered more rapidly than both the untreated control and placebo-cream sites. By day 4, skin hydration at the Calendula site was significantly higher (35.1 AU) than both the placebo site (27.5 AU; p = 0.035) and untreated control site (24.5 AU; p = 0.017), with the superiority over control persisting to day 8 (30.5 vs 25.6 AU; p = 0.043). TEWL, a marker of skin barrier dysfunction, was also significantly lower at the Calendula site on day 3 compared with the untreated control site (30.7 vs 36.7 g/m²/h; p = 0.022), suggesting faster barrier repair. However, there was no significant improvement in erythema/redness, indicating that the primary effect appeared to involve barrier recovery and hydration support rather than any strong anti-inflammatory activity.
The Calendula extract, produced using supercritical CO₂ extraction at 30 MPa and 40 °C, preferentially concentrated volatile lipophilic (fat-loving) constituents rather than polar flavonoids. The result was a resinous, sticky and highly lipophilic extract. Analysis showed a terpene-rich phytochemical profile dominated by sesquiterpenes including γ-cadinene (13.8%), δ-cadinene (13.6%), α-muurolene (7.1%), α-cadinol (6.6%) and t-muurolol (5.5%). This type of Calendula preparation is therefore quite different from a traditional low-alcohol tincture or aqueous extract and is chemically much closer to a very high-strength ethanolic (say 90% ethanol) galenical preparation.
Overall, the study provides preliminary clinical support for the use of a lipophilic Calendula extract in cream form in contact dermatitis. The findings suggest it may function as a barrier-supportive topical that enhances skin hydration and accelerates recovery of impaired skin function. It also aligns with my clinical experience using a high-strength 90% ethanolic Calendula liquid in dermatological practice, especially diluted 1:20 with water for healing of stubborn wounds.
For more information see: https://pubmed.ncbi.nlm.nih.gov/41527980/
