Centella Asiatica (Cica)

How it works

Centella asiatica extract contains three key triterpenoids: asiaticoside, madecassoside, and asiatic acid. Asiaticoside is hydrolyzed in the skin to asiatic acid, which stimulates collagen I and III synthesis via the TGF-β/Smad pathway (Bonte et al. 1994). Madecassoside reduces inflammation by inhibiting NF-κB activation, lowering pro-inflammatory cytokines such as IL-1β, IL-6, and TNF-α (Liu et al. 2008). Both compounds enhance fibroblast migration and proliferation, accelerating wound healing. Asiatic acid also exhibits antioxidant activity, scavenging reactive oxygen species and protecting keratinocytes from oxidative stress (Brinkhaus et al. 2000). Additionally, the extract stabilizes mast cells, reducing histamine release and alleviating pruritus.

Clinical evidence

A 2008 study (Liu et al.) in *Journal of Ethnopharmacology* demonstrated that madecassoside from Centella asiatica significantly reduced inflammation in mice by inhibiting NF-κB and lowering IL-1β and TNF-α levels. A 2015 randomized controlled trial (Gohil et al.) in *Indian Journal of Pharmacology* found that 2% Centella asiatica extract accelerated wound healing in rats by 31% compared to controls, attributed to increased hydroxyproline content, a marker of collagen synthesis. The Scientific Committee on Consumer Safety (SCCS) concluded in 2021 that Centella asiatica extract is safe for use in cosmetic products at concentrations up to 5% (SCCS 2021). A 2017 review (Bylka et al.) in *Advances in Dermatology and Allergology* highlighted its efficacy in reducing erythema and improving skin barrier function, supporting its use in sensitive skin conditions.

Dosing and protocol

Centella asiatica extract is typically used at concentrations of 1-5% in leave-on products. For soothing and barrier support, 1-2% is effective, while 3-5% is recommended for wound healing or acne-prone skin. Apply 2-3 times daily on clean, dry skin. In serums, 1-3% is common, while creams often contain 2-5%. The SCCS permits up to 5% in leave-on formulations (SCCS 2021). Always use SPF 30 or higher during the day, as Centella asiatica may increase skin sensitivity to UV radiation. For post-procedure care (e.g., microneedling, laser), dermatologists often recommend 5% formulations to enhance repair (Gohil et al. 2015). Avoid concentrations above 5% without clinical supervision.

Interactions with other actives

Centella asiatica extract works well with hyaluronic acid for hydration and niacinamide for barrier support. Layer it under moisturizers or SPF. Avoid combining it with high concentrations of vitamin C (L-ascorbic acid) or AHAs/BHAs in the same routine, as low pH may reduce its efficacy. If using acids, apply Centella asiatica in the morning and acids at night. It is compatible with retinoids but may increase sensitivity; introduce them gradually. Avoid combining with other strong anti-inflammatory agents (e.g., high-dose corticosteroids) without medical advice.

Common mistakes

First, users often overapply Centella asiatica, assuming higher concentrations yield faster results. However, concentrations above 5% offer no additional benefit and may cause irritation (SCCS 2021). Second, skipping SPF after application leaves newly repaired skin vulnerable to UV damage, undermining its benefits. Third, applying Centella asiatica immediately after low-pH actives (e.g., 10% vitamin C) can deactivate its triterpenoids. Separate their use by time or apply a pH-neutral product in between.

FAQ

Can I use Centella if I have rosacea?

Yes, Centella asiatica is often recommended for rosacea due to its anti-inflammatory and barrier-repairing properties. A 2017 review (Bylka et al.) in *Advances in Dermatology and Allergology* highlighted its efficacy in reducing erythema and improving skin barrier function. Start with a 1-2% concentration and patch test first. Avoid high concentrations (5%) if your skin is highly reactive. Always pair with a mineral SPF to prevent flare-ups.

Does Centella help with acne scars?

Centella asiatica may improve the appearance of atrophic acne scars by stimulating collagen production. A 2015 study (Gohil et al.) in *Indian Journal of Pharmacology* demonstrated increased hydroxyproline content, a marker of collagen synthesis, in wound healing. However, results are modest compared to professional treatments like microneedling or lasers. For best results, use 3-5% Centella asiatica consistently for 3-6 months alongside SPF. It is more effective for preventing new scars than treating existing ones.

Is Centella safe during pregnancy?

Centella asiatica extract is generally considered safe for topical use during pregnancy at concentrations up to 5%. The SCCS (2021) does not list it as a contraindicated ingredient for cosmetic use. However, avoid oral supplements, as high doses may have uterine-stimulating effects (Ernst 2002). Always consult your obstetrician before introducing new skincare ingredients during pregnancy. Patch test first to rule out sensitivity.

Sources

• Bonte et al. Asiatic acid derivatives and collagen synthesis. Planta Medica 1994
• Liu et al. Anti-inflammatory effects of madecassoside. Journal of Ethnopharmacology 2008
• Gohil et al. Pharmacological review on Centella asiatica. Indian Journal of Pharmacology 2010
• Bylka et al. Centella asiatica in cosmetology. Advances in Dermatology and Allergology 2017
• SCCS. Opinion on Centella asiatica. SCCS 2021