Centella asiatica, commonly called cica or gotu kola, is a plant extract that stimulates collagen production, speeds wound healing, strengthens the skin barrier, and reduces inflammation. It’s one of the most well-studied botanical ingredients in skincare, and it also has a long history of oral use for mood and alertness. Here’s what it actually does in your body and on your skin.
How Centella Builds Collagen
Centella’s main trick is telling your skin cells to produce more collagen, the structural protein that keeps skin firm and resilient. It does this through four active compounds called triterpenes: asiaticoside, madecassoside, asiatic acid, and madecassic acid. These compounds stimulate fibroblasts, the cells responsible for manufacturing collagen, and ramp up the production of type I collagen specifically. Type I is the most abundant collagen in human skin and the type most associated with firmness and wound strength.
The process works at a cellular level. Asiaticoside activates a signaling pathway that triggers fibroblast cells to produce new collagen fibers. Madecassoside does something similar through the same pathway. Beyond just making more collagen, these compounds also increase the metabolism of lysine and proline, two amino acids that form the building blocks of collagen molecules. The result is more raw material and more assembly happening at the same time. In lab studies, centella extract stimulated collagen synthesis more effectively than vitamin C, which is often considered the gold standard for topical collagen support.
Wound Healing and Scar Reduction
Centella has been used for wound care across Asia for centuries, and the science behind it is solid. The extract promotes fibroblast proliferation, meaning it encourages the cells that rebuild damaged tissue to multiply and migrate into the wound site faster. It also increases production of fibronectin, a protein that acts like scaffolding for new tissue, and improves the tensile strength of newly formed skin.
For scars, centella works on multiple fronts. It stimulates scar maturation by boosting type I collagen production while simultaneously reducing the inflammatory reaction that can lead to raised, thickened scars. It also decreases myofibroblast production, which is relevant because myofibroblasts are the cells that cause excessive contraction and the puffy, raised appearance of hypertrophic scars and keloids. Madecassoside has shown particular promise in burn wound healing, where it increases antioxidant activity, enhances collagen synthesis, and influences the growth of new blood vessels to supply healing tissue.
Skin Barrier and Hydration Effects
Centella strengthens the skin barrier, which is the outermost layer that locks moisture in and keeps irritants out. In a clinical study using a formulation containing centella stem cell extract, a single application reduced transepidermal water loss (a direct measure of barrier function) by 52% after one hour and maintained a 48% reduction after 24 hours. Skin hydration increased by 59% after one hour and was still 29% higher after a full day. The untreated control sites showed no improvement at all.
A four-week study testing cosmetic formulations with centella extract found that products containing 5% concentration delivered the best results for both hydration and anti-inflammatory effects, though even 2.5% showed a significant increase in hydration within the first week. The extract also normalizes microcirculation in the skin, which helps with drainage and reduces puffiness.
Anti-Aging and Wrinkle Improvement
A 28-day pilot study tracked what happened when 20 participants applied a centella-based formulation twice daily. Skin elasticity improved steadily throughout the study: roughly 3% by day 7, about 5% by day 14, around 8% by day 21, and 12% to 12.5% by day 28. The effect sizes were large enough to be clinically meaningful, not just statistically significant.
Wrinkle improvement was even more dramatic. Participants saw wrinkle scores improve by 9% to 17% in the first week, 19% to 25% by week two, and 33% to 35% by day 28. These gains reflect centella’s combined effects: more collagen production tightens and firms, better hydration plumps fine lines, and antioxidant activity helps neutralize the reactive oxygen species that break down skin over time.
Anti-Inflammatory and Antioxidant Activity
Centella’s antioxidant properties reduce the activity of reactive oxygen species in skin tissue. This matters because ROS damage is a primary driver of both premature aging and slow wound recovery. Asiaticoside is the main compound responsible for boosting antioxidant levels in healing tissue, with flavonoids in the plant playing a supporting role.
The anti-inflammatory effect is distinct from the antioxidant one. Centella extract calms the inflammatory cascade in skin cells, which is why it’s become a go-to ingredient for sensitive and reactive skin types. Formulations with 5% centella extract demonstrated measurable anti-inflammatory properties in a controlled model of skin microinflammation. This is also why you’ll see cica products marketed for redness, irritation, and post-procedure recovery.
What Oral Centella Does
Taken by mouth, centella has a different profile. A systematic review and meta-analysis of human trials found that oral centella does not produce significant improvements in measurable cognitive functions like memory or processing speed. The brain benefits are subtler and more mood-related: people who took 750 mg per day for two months reported increased alertness and calmness, and a single dose was associated with reduced feelings of anger within an hour.
These shifts in alertness and calm may indirectly support cognitive performance by improving working memory, attention, and the ability to concentrate, but the direct cognitive-boosting effect that centella is sometimes marketed for hasn’t held up in pooled clinical data. If you’re considering oral centella supplements, the realistic expectation is a mild mood-regulating effect rather than a nootropic one. Studies have used doses ranging widely, from 250 mg of extract up to 12 grams in single-dose trials.
How to Choose a Centella Product
For topical use, concentration matters. Clinical evidence supports formulations with at least 2.5% centella extract for hydration benefits, with 5% showing the strongest results for both moisture and inflammation. Many Korean skincare products list centella or “TECA” (titrated extract of centella asiatica) as a key ingredient, but not all disclose the percentage. Products that list centella or one of its four triterpenes high on the ingredient list are more likely to contain a meaningful concentration.
Centella is generally well tolerated on skin. Dermatological reviews note good topical tolerability across studies, though allergic reactions are possible with any botanical ingredient. If you have sensitive skin, patch testing a new centella product on your inner arm for a few days before applying it to your face is a reasonable precaution. The ingredient pairs well with hyaluronic acid for hydration and with niacinamide for barrier repair, and it’s gentle enough for twice-daily use in most routines.