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Centella asiatica, often sold as cica, appears on a great many product pages aimed at redness and sensitivity. Those pages frequently gesture at "clinical research" without saying which research. Below is one specific study, what it reported, and the limits on what you can take from it.
Hur and colleagues published a randomised, double-blind, placebo-controlled trial in Nutrients in 2026, assessing the effects of oral centella asiatica extract on skin ageing-related parameters in middle-aged Korean women.
The design matters here, so it is worth unpacking the terms. Randomised means participants were allocated to groups by chance rather than by choice. Double-blind means neither the participants nor the assessors knew who was receiving the extract. Placebo-controlled means the comparison group received an inactive substitute. That combination is the standard defence against wishful thinking on both sides of a study, and it is a genuinely stronger design than the before-and-after photo sets that dominate ingredient marketing.
112 middle-aged women took part over 12 weeks, taking 200 mg per day of oral centella asiatica extract or placebo.
The authors reported that the extract was associated with reductions in wrinkle-related parameters and in transepidermal water loss. Transepidermal water loss, usually abbreviated TEWL, is a measurement of how quickly water evaporates through the skin. It is one of the standard instrumental proxies for barrier function: lower generally suggests the barrier is holding water more effectively.
On hydration, elasticity and brightness, the authors themselves described the changes as modest and of limited magnitude. That is the study's own characterisation, not an outside critic's, and it deserves as much weight as the positive findings.
This was an oral supplement, not a serum. Participants swallowed 200 mg a day. Nothing in this trial tested centella applied to the face, and results from an ingested extract do not transfer to a topical one. The dose, the route into the body, the concentration reaching skin, and the formulation are all different. A serum's ingredient list sharing a botanical name with a supplement is not the same as sharing its evidence.
The other constraints are ordinary but real. One trial is one trial. The participants were middle-aged Korean women, so how well the findings extend to other ages, skin types and populations is an open question rather than an assumption. Twelve weeks tells you about twelve weeks. And "associated with" is the correct phrasing throughout: this is a measured difference between groups, not a mechanism established for any individual.
Use it as a calibration exercise. When a product page cites clinical proof for cica, the reasonable questions are: which study, was it topical or oral, at what dose, in whom, and did the authors describe the effect as large or modest? If the page cannot answer those, the citation is decoration.
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Why serum-strength actives are moving from face to body, what a body serum can reasonably do, and when a good body lotion is the better buy.
We include centella in our range because it is a well-tolerated, widely used soothing active that many people get on with. We are not going to tell you a serum will do what a 200 mg daily supplement was reported to do in one trial, because that is not what the evidence says, and pretending otherwise is exactly the habit this article exists to push back on.