Memory, Wound Healing, and Anxiety

How Centella asiatica supports the brain, heals tissue, and calms the nervous system

Gotu kola (Centella asiatica) is a small creeping herb used in Ayurvedic and Traditional Chinese Medicine for thousands of years. It is best known for three things: helping the brain stay sharp, supporting wound healing and skin repair, and calming the nervous system without sedation [1][2][3]. Unlike many herbs with a single claim to fame, gotu kola has a body of research spanning cognitive science, dermatology, and anxiety treatment. It grows abundantly in tropical Asia and Africa, and the whole herb is used — not just an isolated extract.

How Gotu Kola Works

The active compounds in gotu kola are triterpenoid saponins — primarily asiaticoside, madecassoside, asiatic acid, and madecassic acid. These molecules have multiple biological effects that explain most of the herb's traditional uses.

In the brain, gotu kola's triterpenoids protect neurons from oxidative damage, support mitochondrial function, and modulate neurotransmitter systems including acetylcholine (the memory neurotransmitter) and GABA (the calming neurotransmitter) [5]. Animal studies consistently show improved spatial memory and reduced anxiety-like behavior. In human trials, elderly volunteers showed improved working memory and mood after eight to twelve weeks of supplementation [1].

For anxiety, gotu kola appears to blunt the body's fight-or-flight response without causing drowsiness. A well-designed human trial measured acoustic startle response — a validated physiological marker of anxiety — and found that a single dose of gotu kola significantly reduced the startle reflex within an hour compared to placebo [2]. This suggests an acute anxiolytic effect, separate from the longer-term cognitive benefits.

For tissue repair, asiaticoside directly stimulates collagen synthesis in fibroblasts [3]. Collagen is the structural protein that holds skin, tendons, and blood vessel walls together. This mechanism explains gotu kola's long clinical history in wound care, keloid treatment, and venous insufficiency (a condition where vein walls and valves weaken, causing swelling and pooling in the legs) [6].

Practical Usage

Gotu kola is available as:

Dried herb / tea: 1–2 g per day, traditionally consumed as a food in Sri Lanka and South Asia
Standardized extract (40% triterpenoids): 60–120 mg per day, the dose used in most clinical studies
Fresh juice or powder: used topically for skin and wound applications

Most cognitive and anxiety studies used 500–750 mg of dried extract once or twice daily. Effects on mood and alertness are sometimes reported within a few days, while structural benefits to skin and veins take weeks to months.

Cautions

Gotu kola is generally well tolerated at typical doses. It should be avoided during pregnancy (it has historically been used to stimulate uterine contractions). High doses can affect the liver in rare cases — those with liver conditions should use caution. It may potentiate sedative medications. Topical use rarely causes contact dermatitis.

See our ashwagandha page for another well-studied adaptogen, or our lemon balm page for a simpler, gentler option for anxiety.

Evidence Review

Cognitive Function

The most thorough human trial on gotu kola and cognition (Wattanathorn et al., 2008; PMID 18191355) enrolled healthy elderly volunteers in a randomized, placebo-controlled design. Participants received 250 mg, 500 mg, or 750 mg of a standardized extract for two months. The 750 mg group showed significant improvements in working memory and a measurable change in the N100 event-related potential — a brain wave marker associated with attention and cognitive processing speed. This dose-dependent response is reassuring from a mechanistic standpoint.

A 2017 systematic review and meta-analysis by Puttarak et al. (PMID 28878245) analyzed 11 randomized controlled trials of Centella asiatica for cognitive and mood outcomes. The pooled analysis found significant improvements in mood outcomes including alertness, calmness, and reduced anger scores. Cognitive domain results were more mixed — some trials showed memory benefits while others did not — suggesting that study population, dose, and extract standardization matter considerably. The reviewers rated the overall evidence as moderate quality with potential for publication bias.

Anxiety

Bradwejn et al. (2000; PMID 11106141) conducted a randomized, double-blind, placebo-controlled crossover trial in 40 healthy adult volunteers. A single oral dose of 12 g of dried gotu kola (equivalent to ~500 mg of 24:1 extract) significantly attenuated the peak acoustic startle response at 30 and 60 minutes post-dose compared to placebo (p<0.05). The acoustic startle response is a validated biomarker of anxiety with good reproducibility. The study found no effect on baseline anxiety ratings, suggesting gotu kola dampens reactivity rather than inducing sedation — a clinically meaningful distinction.

Wound Healing and Collagen

Maquart et al. (1990; PMID 2354631) established the mechanistic foundation: asiaticoside isolated from gotu kola dose-dependently stimulated type I and III collagen synthesis in human fibroblast cultures without cytotoxicity. This in vitro work has been replicated in animal wound models where topical and oral asiaticoside application accelerated wound closure and increased breaking strength of healed tissue.

Clinically, the strongest evidence is in chronic venous insufficiency. A 2013 systematic review by Chong and Aziz (PMID 23533507) searched 13 databases and identified trials with adequate controls. Across multiple trials, Centella asiatica extract (TTFCA — total triterpenic fraction) significantly improved microcirculatory parameters: transcutaneous oxygen and carbon dioxide levels, ankle swelling, and venoarteriolar response. The consistent direction of effect across independent trials supports the mechanistic plausibility of vascular wall collagen strengthening.

Neuroprotection

Wong et al. (2021; PMID 34267660) reviewed the emerging evidence for Centella asiatica in neurodegenerative disease. The review catalogues multiple mechanisms: mitochondrial protection, reduction of amyloid-beta aggregation in Alzheimer's models, dopaminergic neuron protection in Parkinson's models, and anti-neuroinflammatory effects via suppression of NF-kB signaling. Most of this evidence comes from cell culture and animal models. Human trials specifically targeting neurodegeneration are limited, but the mechanistic breadth is notable and justifies ongoing clinical research.

Confidence Assessment

Anxiety (acute): Moderate — supported by a well-designed RCT with objective biomarker; sample size small (n=40)
Mood and alertness: Moderate — consistent across multiple trials per meta-analysis
Cognitive enhancement (elderly): Low-to-moderate — promising but inconsistent across trials; needs larger replication
Wound healing (topical/venous): Moderate-to-high — mechanistically solid, supported by multiple independent clinical trials
Neuroprotection: Low (human evidence) — strong mechanistic basis but clinical trials in neurodegeneration are lacking

Gotu kola is one of the more multifaceted herbal medicines, with genuine peer-reviewed support across several distinct clinical areas. The anxiety and wound healing evidence is strong enough to inform practical use; the cognitive evidence is promising but not yet definitive.

References

Positive modulation of cognition and mood in the healthy elderly volunteer following the administration of Centella asiaticaWattanathorn J, Mator L, Muchimapura S, Tongun T, Pasuriwong O, Piyawatkul N, Yimtae K, Sripanidkulchai B, Singkhoraard J. Journal of Ethnopharmacology, 2008. PubMed 18191355 →
A double-blind, placebo-controlled study on the effects of Gotu Kola (Centella asiatica) on acoustic startle response in healthy subjectsBradwejn J, Zhou Y, Koszycki D, Shlik J. Journal of Clinical Psychopharmacology, 2000. PubMed 11106141 →
Stimulation of collagen synthesis in fibroblast cultures by a triterpene extracted from Centella asiaticaMaquart FX, Bellon G, Gillery P, Wegrowski Y, Borel JP. Connective Tissue Research, 1990. PubMed 2354631 →
Effects of Centella asiatica (L.) Urb. on cognitive function and mood related outcomes: A Systematic Review and Meta-analysisPuttarak P, Dilokthornsakul P, Saokaew S, Dhippayom T, Kongkaew C, Sruamsiri R, Chuthaputti A, Chaiyakunapruk N. Scientific Reports, 2017. PubMed 28878245 →
Mitoprotective Effects of Centella asiatica (L.) Urb.: Anti-Inflammatory and Neuroprotective Opportunities in Neurodegenerative DiseaseWong JH, Barron AM, Abdullah JM. Frontiers in Pharmacology, 2021. PubMed 34267660 →
A Systematic Review of the Efficacy of Centella asiatica for Improvement of the Signs and Symptoms of Chronic Venous InsufficiencyChong NJ, Aziz Z. Evidence-Based Complementary and Alternative Medicine, 2013. PubMed 23533507 →