Triterpenes

What is Triterpenes?

Triterpenes are not one supplement. They are a chemical family — molecules built from six five-carbon isoprene units, giving a 30-carbon skeleton — found across thousands of plants and fungi. When a label says "triterpenes" it is describing a shape, not an ingredient, in roughly the way "flavonoids" or "alkaloids" does. Caffeine and strychnine are both alkaloids; boswellic acid and cucurbitacin E are both triterpenes.

That matters because the members of this family behave very differently. Escin from horse chestnut seed tightens leaky veins. Boswellic acids from frankincense resin dampen a specific inflammatory enzyme pathway. Glycyrrhizin from licorice blocks an enzyme in the kidney and can push blood pressure up. Ganoderic acids give reishi its bitterness. Cucurbitacins from wild gourds are cytotoxic and have poisoned people who drank bitter bottle-gourd juice.

So the sensible way to read any claim about triterpenes is to ask which one, from which plant, at what dose, standardised how. A small number of triterpene-rich extracts have respectable human trial records. A much larger number of individual triterpenes — ursolic acid, betulinic acid, lupeol, maslinic acid — are laboratory stars with almost no controlled human data behind them, despite being sold as if the two things were the same.

How does Triterpenes work?

There is no single mechanism, because the class shares a carbon skeleton rather than a target. Several of the better-studied members interfere with inflammatory signalling: boswellic acids inhibit 5-lipoxygenase and microsomal prostaglandin E synthase, reducing leukotriene and prostaglandin production. Escin acts on venous wall tone and capillary permeability, which is why it reduces fluid leaking into swollen legs. Centella's asiaticoside and madecassoside stimulate collagen synthesis and fibroblast activity in healing tissue. Glycyrrhizin inhibits 11-beta-hydroxysteroid dehydrogenase type 2, which lets cortisol act on mineralocorticoid receptors — the reason it causes potassium loss and fluid retention. Many triterpene saponins are also surfactant-like, which explains both their absorption problems and their tendency to irritate the stomach. Most isolated triterpenes are poorly absorbed and rapidly cleared, a gap that laboratory studies routinely ignore.

What forms does Triterpenes come in?

Standardised extracts are the only forms with meaningful clinical grounding. Boswellia serrata is typically standardised to 30–65% boswellic acids, or to a defined AKBA content (5–30%) in branded preparations. Horse chestnut seed extract is standardised to escin content, usually 16–20% giving 50 mg escin per dose. Centella asiatica is sold as a "total triterpenic fraction" containing defined asiaticoside, asiatic acid and madecassic acid. Reishi extracts vary enormously and are often standardised to combined polysaccharide and triterpene percentages of dubious reliability. Isolated ursolic acid, betulinic acid and lupeol powders exist as consumer supplements but have no established human dose, no standard formulation and poor oral bioavailability. Topical Centella and birch-bark betulin preparations are used for scars and wound healing. Glycyrrhizin appears both in licorice extracts and, in Japan, as a prescription intravenous drug (SNMC) for liver disease — that is a medical setting, not a supplement one.

Where it comes from:

The chemistry is modern; the plants are ancient. Frankincense resin (salai guggul) has been used in Ayurveda for inflammatory and joint conditions for well over two thousand years, and Boswellia is named in the classical Sanskrit texts. Centella asiatica (gotu kola, brahmi in some usages) appears in both Ayurvedic and Chinese materia medica for wounds and skin. Reishi (lingzhi, 霊芝) is one of the most revered tonics in Chinese medicine. Licorice is among the most-used single herbs in Chinese and Kampo formulas. Horse chestnut has a European folk record for varicose veins. Chemists only began isolating and naming the triterpene skeletons in the nineteenth and twentieth centuries, and the marketing category of "triterpene supplements" is a recent invention that groups these unrelated traditions together under one chemical heading.

What does Triterpenes help with?

• Knee osteoarthritis and joint stiffness: This is the strongest joint-related evidence in the class, and it belongs specifically to standardised Boswellia serrata extracts rather than to triterpenes generally. Several randomised trials, most of them small and many industry-funded, report reductions in knee pain and improved function over 4–12 weeks compared with placebo, with effect sizes that are modest but reasonably consistent. Meta-analyses have called the evidence promising but limited by trial quality and by the fact that different branded extracts are not interchangeable. It is not a substitute for a diagnosis or for physiotherapy.
• Chronic venous insufficiency, leg swelling and heaviness: Horse chestnut seed extract standardised to escin has one of the better evidence bases here: a Cochrane review of placebo-controlled trials found reductions in leg pain, oedema and itching over a few weeks, though it noted that trials were mostly short and of moderate quality. Centella asiatica's total triterpenic fraction has smaller supportive trials for venous symptoms and microcirculation. These extracts ease symptoms; they do not correct the underlying vein damage, and compression therapy remains the standard. Sudden swelling in one leg needs medical assessment, not a supplement.
• Wound healing, scars and stretch marks (topical): Topical Centella asiatica preparations containing asiaticoside and madecassoside have small clinical trials and long dermatological use for scar appearance, stretch mark prevention in pregnancy and support of wound healing, plausibly through increased collagen synthesis. Birch-bark betulin gel has been studied in specific wound settings. The trials are small, often unblinded, and outcomes are frequently subjective scar-appearance scores. Reasonable to try on established scars; not appropriate on open, infected or surgical wounds without medical advice.
• Inflammatory bowel conditions: Boswellia extracts have been trialled in ulcerative colitis and Crohn's disease based on their effect on leukotriene pathways. A few small studies suggested it might be comparable to mesalazine in mild ulcerative colitis, but a larger placebo-controlled maintenance trial in Crohn's did not show benefit over placebo. The honest summary is that this remains unproven. Inflammatory bowel disease requires specialist management, and swapping prescribed maintenance therapy for a botanical extract carries a real risk of relapse.
• Asthma and airway inflammation: The leukotriene-blocking mechanism of boswellic acids is the same pathway targeted by drugs like montelukast, which makes the idea biologically reasonable. A small number of older, mostly small trials reported improvements in symptoms and lung function measures with boswellia extracts, sometimes combined with other herbs. The studies are too few, too small and too old-methodology to support recommending this for asthma. Asthma is a condition where undertreatment can be dangerous; rescue and preventer inhalers should not be substituted.
• Blood sugar and metabolic markers: Corosolic acid from banaba leaf, maslinic and oleanolic acid from olive leaf, and ginsenosides from ginseng have all been proposed as glucose-lowering triterpenes. Human evidence is limited to small short-term trials with inconsistent results and modest changes in fasting glucose or HbA1c. Nothing here is strong enough to influence diabetes management, and the combination of a glucose-lowering supplement with prescribed diabetes medication can push blood sugar too low. Discuss with whoever manages your diabetes before starting.
• Liver health and chronic hepatitis: Glycyrrhizin, the main triterpene saponin of licorice, has been used in Japan for decades as an intravenous preparation (Stronger Neo-Minophagen C) in chronic hepatitis, with observational and some trial data on liver enzymes. That is a prescription drug given under monitoring, and it does not transfer to oral licorice supplements — which at sustained doses cause potassium loss, fluid retention and raised blood pressure. Oral licorice or glycyrrhizin should not be self-prescribed for liver disease.
• Fatigue and quality of life during cancer treatment: Reishi (Ganoderma lucidum), whose triterpene fraction includes the ganoderic acids, has been studied as an adjunct in cancer care. A Cochrane review found the evidence too weak to justify reishi as a first-line treatment and noted that trials were small and of poor quality, with a suggestion of improved immune markers and some quality-of-life benefit. Reishi can also interact with anticoagulants and may not be appropriate alongside some treatments. This is a conversation to have with an oncology team, not a self-directed decision.

What can Triterpenes help prevent?

• Progression of leg oedema symptoms in chronic venous insufficiency — escin-standardised horse chestnut extract reduces swelling and heaviness over weeks in placebo-controlled trials, though it has not been shown to prevent the underlying vein disease from advancing
• Visible scarring after wound closure: topical Centella triterpene preparations have small trials suggesting better scar appearance and some use for stretch mark prevention in pregnancy, with modest and largely subjective evidence
• No triterpene supplement has been shown in humans to prevent cancer, heart disease or dementia, despite extensive laboratory work often quoted to that effect

Which foods are rich in Triterpenes?

Triterpenes are ordinary parts of a plant-rich diet, and the dietary route is the safest way to get them. Apple peel is one of the richest common sources of ursolic acid — eat apples unpeeled. Extra-virgin olive oil and olive leaf provide oleanolic and maslinic acid. Rosemary, thyme, basil, oregano, sage, holy basil and peppermint all contain ursolic acid, and the herbs contribute more per gram than most fruits. Cranberries, blueberries, bilberries and tomato skins add oleanolic and related acids. Whole ginseng root, reishi as a decoction, and licorice root tea deliver the saponin-type triterpenes — licorice tea only occasionally, not daily. Chaga and reishi mushrooms are traditional sources of betulin-family and ganoderic triterpenes. Foods to be careful with: any gourd, courgette, squash or bottle gourd that tastes bitter should be spat out and thrown away — the bitterness is cucurbitacin, and bitter bottle-gourd juice has caused serious poisoning. Regular daily licorice confectionery or licorice tea is the other food-side risk, for the blood pressure and potassium reasons described above.

What are the side effects of Triterpenes?

• Stomach upset, nausea, reflux or diarrhoea: the most common complaint across triterpene-rich extracts, particularly boswellia and saponin-containing products
• Itching or rash, occasionally with horse chestnut extract
• Headache and dizziness at higher doses of several extracts
• Licorice/glycyrrhizin-containing products: low potassium, fluid retention, raised blood pressure, ankle swelling, muscle weakness or cramps — this is pseudoaldosteronism and it can become serious with prolonged use or with diuretics
• Reishi: dryness of the mouth and throat, nosebleeds, and rare reports of liver enzyme elevation with powdered preparations
• Ginseng saponins: insomnia, jitteriness and blood-pressure changes
• Increased bleeding tendency with escin, reishi and ginseng, especially alongside anticoagulants
• Cucurbitacin-containing bitter gourd or bottle-gourd preparations: severe vomiting, diarrhoea and gastrointestinal bleeding — these are genuine poisonings, not side effects
• Unpurified horse chestnut (raw seed, bark, leaf) is toxic; only standardised seed extract is used

Good to know:

Safety cannot be generalised across this class. Some triterpenes are ordinary dietary constituents found in apple peel and olive oil; others, such as cucurbitacins and celastrol, are potent cytotoxic compounds with narrow safety margins. Judge the specific product, not the category, and be sceptical of any supplement that lists "triterpenes" as its active ingredient without naming which ones and how much.

How much Triterpenes should you take?

• Recommended daily: There is no dose for "triterpenes" — only for specific standardised extracts. Boswellia serrata extract standardised to 30–65% boswellic acids: typically 300–400 mg two to three times daily, or 100–250 mg daily of high-AKBA branded extracts. Horse chestnut seed extract standardised to escin: typically 300 mg twice daily, delivering about 100 mg escin per day. Centella asiatica total triterpenic fraction: about 60–120 mg daily in divided doses; topical creams usually 1–7% applied twice daily. Reishi extract doses vary widely and are poorly standardised. For isolated ursolic acid, betulinic acid, oleanolic acid or lupeol there is no established safe or effective human dose, and none should be assumed from cell studies. Licorice-derived glycyrrhizin should be kept well below 100 mg per day and ideally avoided as a deliberate supplement.
• Best time of day: Boswellia is usually split across the day to keep levels steady. Horse chestnut is taken morning and evening. Topical Centella is applied morning and night to clean skin.
• With or without food: Take with food. Most triterpenes are fat-soluble and absorb better with a meal containing some fat; several, particularly boswellia and horse chestnut, also cause reflux or stomach irritation on an empty stomach.
• Time to effect: Escin for leg oedema: often noticeable within 2–4 weeks. Boswellic acids for joint symptoms: usually 4–8 weeks, though some high-AKBA extracts have reported earlier changes. Topical Centella on scars: 6–12 weeks. Isolated triterpene compounds: no reliable human timeline exists.
• How long to take it: Most trials ran 4–12 weeks. Reassess at 8–12 weeks — if there is no clear benefit, stop rather than escalate. Any product containing licorice or glycyrrhizin should be limited to short courses (a few weeks) unless supervised, because the pseudoaldosteronism risk rises with duration. Stop at least two weeks before planned surgery.