A Randomized, Double-Blind, Placebo-Controlled Trial Assessing the Effects of Oral Centella asiatica Extract on Skin Aging-Related Parameters in Middle-Aged Korean Women.

The short version

This randomized, double-blind, placebo-controlled trial with 112 women explored whether an oral Centella asiatica extract, taken as a daily tablet, changes measurable signs of skin aging. Centella asiatica, also called gotu kola, is traditionally used in Asian and Ayurvedic medicine for wound healing and skin problems. Skin aging here means deeper wrinkles, lower hydration, a weaker skin barrier (measured as water loss through the skin, TEWL) and less elasticity. The authors note that evidence for taking Centella by mouth for skin was limited and often based on small or subjective studies. Women aged 30 to 60 with visible crow's feet and fairly dry cheek skin were randomly assigned in Seoul to take either 200 mg a day of a standardized leaf extract (InnerCica, with asiaticoside as the marker compound) or an identical placebo for 12 weeks. Neither participants nor assessors knew who received which. Wrinkle depth, volume and roughness were measured with 3D skin imaging, and hydration, TEWL, elasticity and skin color with non-invasive probes at baseline, 6 and 12 weeks. After 12 weeks, average wrinkle depth fell by 5.87 micrometres with the extract versus 1.96 with placebo (p = 0.018; an 11.1% drop from the extract group's baseline). The deepest wrinkle, wrinkle volume and roughness also improved more than with placebo. Cheek hydration rose and cheek water loss fell more with the extract (p < 0.001 and p = 0.005), but gains in elasticity and brightness were only about 0.7%, which the authors call modest. Three mild adverse events (one extract, two placebo) were judged unrelated, and blood tests stayed normal. The authors treat wrinkle depth as the confirmed result and everything else as supportive. They note the study included only women, tested one dose for 12 weeks, did not measure how the extract might work, and did not adjust for testing many outcomes, so long-term effects remain unknown. They call for longer, more diverse studies.

Key findings

• In this 12-week study, 112 women aged 30 to 60 with visible wrinkles took either a daily 200 mg Centella asiatica (gotu kola) extract tablet or an identical placebo.
• Average wrinkle depth fell by 5.87 micrometres with the extract compared with 1.96 with placebo, and the result was statistically significant (p = 0.018).
• Skin moisture on the cheek rose and water loss through the skin fell more with the extract, but improvements in elasticity and brightness were small, about 0.7%.
• Three mild side effects were reported (one with the extract, two with placebo), and none were judged to be caused by the product.
• The study included only women, used one dose for 12 weeks, and did not measure how the extract might work, so longer-term effects are unknown.

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