Gotu Kola

Centella asiatica (L.) Urb. belongs to Apiaceae (Umbelliferae), the carrot and parsley family; its older name is Hydrocotyle asiatica L., and NCBI Taxonomy files it as taxon 48106. EMA’s assessment report describes a slender, stoloniferous perennial that creeps along the ground and roots at the nodes, growing in damp places in tropical countries. The leaves are rounded to kidney- or fan-shaped, with a blade typically 10–40 mm long and 20–40 mm wide, sometimes up to 70 mm, held on a stalk that is usually five to ten, even fifteen, times longer than the blade. The flowers are tiny and inconspicuous, borne in small clusters close to the ground. EMA lists it as native to Asian countries such as Sri Lanka and Malaysia, as well as Madagascar and South Africa, and LiverTox describes it as native to tropical Southeast Asia and Australia. It is eaten as a vegetable as well as used as medicine.

Names are a minefield. EMA records Indian pennywort, Jal Brahmi, Brahmi-Buti, and Mandukaparni (the Ayurvedic name) in India, and gotu kola, its Sinhala name, is now the usual English trade name. Because brahmi is also the common name of Bacopa monnieri, a quite different creeping wetland herb used in Ayurveda for memory, the two are often swapped. Shah and colleagues (Molecular Biology Reports 2023) note that brahmi is used for both species; when they tested market brahmi products, only 22–56% tested positive for the expected plants, depending on the method. Thai researchers (Suksawat, Scientific Reports 2025) also found gotu kola confused with Hydrocotyle umbellata, a lookalike pennywort, in online products.

The medicinally interesting compounds are pentacyclic triterpenes, sometimes called centelloids. EMA names the saponins asiaticoside (PubChem CID 11954171, C48H78O19) and madecassoside (CID 24825675, C48H78O20) and their aglycones asiatic acid (CID 119034) and madecassic acid (CID 73412) as the most abundant; saponins can reach 8% of the dried herb, but levels vary widely with geography, genetics, and growing conditions. The European Pharmacopoeia requires the dried aerial parts to contain at least 6.0% total triterpenoid derivatives, expressed as asiaticoside. The leaves also contain flavonoids such as quercetin and kaempferol, chlorogenic acids, and a little essential oil. TECA, TTFCA, and TTF are different acronyms for the same purified extract, about 40% asiaticoside and 60% asiatic and madecassic acids, which EMA says is so heavily processed that it no longer counts as a herbal preparation.

EMA’s assessment report notes that gotu kola is referred to in the Chinese Shennong Herbal, about 2,000 years old, that Chinese physicians prescribed the leaves for leucorrhoea and fever, and that in Ayurvedic medicine it is described under the name Mandukaparni for conditions ranging from asthma and bronchitis to skin diseases, leprosy, and urinary complaints. In Malaysia it is eaten fresh as a salad vegetable and reputed to improve memory and ease mental fatigue and anxiety, and on Java and the Malay Peninsula fresh extracts were used both on wounds and as a brain tonic. Bradwejn and colleagues (Journal of Clinical Psychopharmacology 2000) note its long use in Ayurvedic and Chinese medicine for depression and anxiety. In Sri Lanka, where Chandrika and Prasad Kumarab (Advances in Food and Nutrition Research 2015) describe it as one of the most commonly eaten leafy greens, it is shredded raw with grated coconut, onion, chilli, and lime as gotu kola sambol or mallum, and cooked into a green herbal porridge.

Western medicine met the plant through leprosy. EMA records that in 1852 Boileau, a French doctor in Mauritius, reported using the whole plant to treat leprosy, after which it was tried on leprosy patients in hospitals in Madras and entered the Indian pharmacopoeia. Centella appeared in the French Codex in 1884, the first dry extract was made in 1941, and around that time the French scientist P. Boiteau isolated its triterpene molecules. The British Herbal Pharmacopoeia of 1983 recorded the aerial parts taken by mouth for rheumatic and skin conditions and applied to indolent wounds, leprous ulcers, and surgical scars, at 0.6 g three times daily.

Modern European use grew around the purified extract. A sterile dressing impregnated with TECA (Madecassol) has been authorized in France since 1976 for the granulating phase of wounds and skin ulcers, and TECA tablets, creams, ointments, and powders are authorized in Belgium, France, Greece, Italy, Portugal, and Spain for wounds, hypertrophic scars and keloids, burns, and venous insufficiency (EMA). EMA’s herbal committee first reviewed the plant in 2009–2010 and ended with a public statement that no monograph could be established, because the only products on the market used the purified extract. On revisiting the evidence, it adopted a monograph on 30 March 2022 covering only traditional cutaneous use of the plain herb, based on the British Herbal Pharmacopoeia.

Most mechanistic work concerns skin repair. EMA’s assessment report summarizes laboratory studies in which asiaticoside induced type I collagen synthesis in human skin fibroblasts, sped burn wound repair in animals at very low doses, and increased the migration of fibroblasts and keratinocytes in culture. MSKCC adds that asiaticoside stimulates collagen and glycosaminoglycan synthesis and the growth of new blood vessels, and has anti-inflammatory effects on cytokines such as TNF-alpha and IL-6 in animal models. Paradoxically for a wound-healing herb, asiaticoside, asiatic acid, and madecassoside reduced proliferation and collagen production in fibroblasts taken from keloids, the overgrown scars that some people form, which is the laboratory rationale for using the extract on hypertrophic scars.

For veins, the proposed action is on the microcirculation rather than the large veins. In small trials of TTFCA, De Sanctis and colleagues (Angiology 2001) reported reduced capillary filtration and ankle swelling, and EMA lists improvements in filtration rate, skin oxygen and carbon dioxide levels, resting blood flow, and capillary permeability at 60–180 mg a day. TTFCA at 30 mg twice daily for three months also lowered serum enzymes involved in mucopolysaccharide metabolism, part of connective tissue turnover, in people with varicose veins (EMA). None of these measures has been linked to hard outcomes such as ulcer prevention.

The brain effects claimed for gotu kola rest mostly on animal studies. MSKCC notes that a water extract prevented beta-amyloid aggregates in a mouse model of Alzheimer’s disease, and Bradwejn’s group was drawn to the plant because some herbs with reputed calming effects bind to cholecystokinin receptors involved in fear and anxiety. Little is known about how gotu kola is absorbed or handled by the body: EMA states that pharmacokinetic data for the herb and its preparations are missing. In laboratory tests it inhibits several liver enzymes that metabolize drugs (MSKCC), with unknown clinical relevance.

Chronic venous insufficiency is the best-studied use, almost entirely with the purified extract. Pointel and colleagues (Angiology 1987) randomized 94 people with venous insufficiency of the legs to TECA 120 mg a day, 60 mg a day, or placebo for two months; heaviness, oedema, and the patients’ overall assessment improved with TECA, and vein distensibility improved rather than worsening as it did on placebo. De Sanctis and colleagues (Angiology 2001) gave TTFCA 60 mg or 30 mg three times daily or placebo for four weeks to small groups with venous hypertension and found dose-related falls in capillary filtration, ankle circumference, and symptoms, with 180 mg a day working best. That trial was one of a cluster of small studies published together in a 2001 supplement of Angiology, largely by the same research group.

Reviews are cautious. Chong and Aziz (Evidence-Based Complementary and Alternative Medicine 2013) found eight randomized trials and pooled data showing improvements in microcirculation measures and ankle swelling, but warned that most studies were poorly reported with unclear risk of bias. Cochrane’s review of phlebotonics (Martinez-Zapata, 2020) included only two Centella trials among 56 with usable data; for phlebotonics as a class it found moderate-certainty evidence of a slight reduction in leg oedema, little or no difference in quality of life, and low-certainty evidence of no effect on ulcer healing. MSKCC says several trials suggest benefit for venous insufficiency but that there is no evidence gotu kola treats ordinary high blood pressure.

Wounds, burns, and scars: the evidence is suggestive but thin. In Thailand, Paocharoen (Journal of the Medical Association of Thailand 2010) enrolled 200 people with diabetic foot wounds and gave capsules providing 50 mg of asiaticoside, two capsules three times daily, or placebo, assessing wounds over three weeks; wound contraction was better with gotu kola, but granulation tissue formed better on placebo. In Iran, Saeidinia and colleagues (Medicine 2017) randomized 75 people with partial-thickness burns and analysed 60; an ointment of Centella extract healed burns in about 15 days on average against about 22 days with silver sulfadiazine cream. A Thai trial of a 7% Centella cream on skin graft donor sites (Jenwitheesuk, 2018) improved only scar pigmentation, with 23 of 30 patients completing, and a trial in 153 women having breast radiotherapy (Thanthong, Integrative Cancer Therapies 2020) found that a Centella cream neither reduced nor delayed radiation dermatitis. EMA concluded that design flaws and poorly described preparations made the wound trials insufficient for well-established use.

Memory and cognition: Wattanathorn and colleagues (Journal of Ethnopharmacology 2008) gave 28 healthy older adults 250, 500, or 750 mg of extract daily for two months and reported better working memory and mood on the highest dose. But Puttarak and colleagues (Scientific Reports 2017), pooling 11 randomized trials, found no significant difference from placebo in any cognitive domain; gotu kola might increase alertness and reduce anger an hour after a dose. EMA noted doses in these studies ranging from 40 mg to 12,000 mg a day, often with other ingredients, and concluded there were no grounds for use to improve cognition.

Anxiety: in a small experiment, Bradwejn and colleagues (2000) gave 40 healthy volunteers a single 12 g dose of powdered herb or placebo; gotu kola reduced the startle reflex to a loud noise at 30 and 60 minutes but did not change self-rated mood, heart rate, or blood pressure. A small Indian study of 33 people with generalized anxiety disorder (Jana, 2010) reported lower anxiety scores after 500 mg twice daily for 60 days. EMA judged the number and quality of anxiety trials insufficient, and MSKCC says the evidence is insufficient for anxiety or cognition.

EU traditional use (EMA/HMPC/489142/2020, adopted 30 March 2022): for adults and older people only, to aid the healing of minor wounds. Either 0.6 g of the cut dried herb is infused in a small amount of boiling water and the still-warm infusion used to soak a dressing applied to the wound three times daily, or 0.6 g of powdered herb is applied directly to the wound three times daily, a maximum of 1.8 g a day. Do not use for more than one week; if the wound has not improved, or worsens, see a doctor or qualified healthcare practitioner. EMA does not recommend use under 18 because of a lack of data, or during pregnancy or breastfeeding.

Purified extract products: TECA or TTFCA is sold as tablets (10 or 30 mg), 1% creams and ointments, 2% powders, and impregnated dressings, under medicinal licences in several EU countries (EMA). The venous trials used 60–180 mg a day by mouth, divided into two or three doses, for four weeks to two months; capsules of 30 mg of asiatic acid, taken twice daily, are authorized in Portugal for venous insufficiency. These are medicines with their own product information, not interchangeable with gotu kola leaf supplements, whose extract type and strength are usually unstated. EMA notes that no information is available on the extracts used in food supplements.

Food and supplements: fresh gotu kola leaves are a common vegetable in Sri Lanka and Southeast Asia, eaten raw in salads and sambols, cooked in porridge, or juiced. Supplements sold for memory or anxiety vary widely, from crude leaf powder to ethanolic extracts, with doses in trials from 40 mg to 12 g a day and little standardization. Because EMA would not accept oral use of the herb, there is no regulator-endorsed oral dose. Anyone choosing an oral product should keep courses short, avoid it with liver disease or alongside other liver-stressing substances, and stop at the first sign of liver trouble.