Indian Frankincense (Boswellia serrata): A Comprehensive Reference
1. Identity, Botanical Description, and Source
Boswellia serrata Roxb. (known as "Indian olibanum" or "Indian frankincense"), is a moderate to large sized branching tree of the family Burseraceae (genus Boswellia) that grows in dry mountainous regions of India, Northern Africa and the Middle East. The plant is native to much of India and the Punjab region that extends into Pakistan. Within India, the States of Andhra Pradesh, Gujarat, Madhya Pradesh, Jharkhand, and Chhattisgarh are the main sources.
The tree has a large crown spread out flat, with 9 to 14 pairs of pinnate leaves; its greenish ash-colored bark peels off in papery, smooth pieces. Indian frankincense is collected twice a year (in March and June), with cuts made in the trees months beforehand, with each tree yielding about 1 kg of gum resin per year.
1.1 Nomenclature and Regional Names
"Shallaki," "Kundur," "salai," and "guggul" are among the most prominent regional names. "Shallaki" is a widely used active ingredient in Unani, Siddha, and Ayurvedic medicines oriented toward the treatment of inflammation and pain. The plant is also identified in scientific literature under the synonymous designation Boswellia serrata Roxb. ex Colebr.
1.2 Taxonomic Context Within the Genus
Some well-known species within the genus include Boswellia sacra (commonly known as Omani frankincense), Boswellia serrata (Indian frankincense), and Boswellia carteri (African frankincense). The taxonomy of Boswellia is complex, and distinguishing between species can be challenging due to their morphological similarities; DNA analysis and chemical profiling of resins have been valuable tools for taxonomists in classifying different species accurately. Boswellia serrata is particularly noted for its high content of boswellic acids, especially AKBA (3-O-acetyl-11-keto-β-boswellic acid), which is associated with potent anti-inflammatory effects.
1.3 Resin Collection and Raw Material
Oleo gum-resin is tapped from incisions made on the trunk of the tree and is then stored in specially made bamboo baskets for removal of oil content and for getting the resin to solidify. After processing, the gum-resin is graded according to its flavor, color, shape, and size. The gum resin from the tree hardens into lumps of various shapes. These lumps are yellowish to brownish in color, irregularly spherical or resembling stalactites, and light gray with a dusting. They are easy to break, with a conchoidal, waxy fractured surface.
1.4 Composition of the Raw Oleo Gum-Resin
The oleo gum-resins contain 30–60% resin, 5–10% essential oils (soluble in organic solvents), and the rest is made up of polysaccharides. Indian frankincense contains about 60% resin, including various boswellic acids (pentacyclic triterpenic acids), as well as polysaccharides (gums) and essential oils.
1.5 Common Dosage Forms and Commercial Preparations
Boswellia serrata is a branching tree native to the mountainous regions of Northern Africa, India, and the Middle East; boswellia is an herbal extract made from the gum resin or bark of the tree and can be taken orally or applied topically. Commercial forms include standardized dry extracts in capsule and tablet form, topical preparations, and essential oils derived from the resin. Many different extracts of Boswellia gum resin have been prepared; the most prominent are Boswellia serrata acidic extract, Boswellia serrata non-acidic extract, and water-soluble extract containing polysaccharides. Proprietary standardized extracts sold under trade names such as H15, Boswelan, 5-Loxin, Aflapin, and Boswellin Super are used in clinical research and commercial supplements.
2. Traditional and Historical Use
2.1 Ayurvedic Medicine
The resin is rich in triterpenic acids and has been used for centuries in traditional Ayurvedic medicine to treat inflammatory conditions. Ancient writers of the Charaka Samhita and Sushruta Samhita mention Boswellia serrata resin under names like "Shallaki" and "Dhawalp"; these texts, dating back over 2,000 years, often cited Shallaki as a key component in formulations targeting joint pain and respiratory health.
The gum resin of Boswellia serrata, known in the vernacular as "Sallai guggal," was used in the Ayurvedic system of medicine for the management of rheumatism, respiratory diseases, and liver disorders. Extracts have been used in Ayurvedic medicine for their anti-inflammatory, antiseptic, astringent, and stimulant activity to treat inflammatory conditions and gastrointestinal complaints.
In ancient Ayurvedic texts, particular methods describe the extraction, purification, and usage of this oleo gum resin. During medieval periods, Yadava and Maratha physicians in central India developed refined methods to collect and purify the resin — sometimes using cow's milk and herbal decoctions to reduce impurities. In the northern Himalayan traditions, the resin was often consumed in milk decoctions (Kshira Paka) — a preparation method that demonstrates pharmacological sophistication, since milk's fat content would enhance the bioavailability of the resin's lipophilic boswellic acid constituents.
2.2 Other Traditional Medical Systems
"Shallaki" is a widely used active ingredient in the Unani, Siddha, and Ayurvedic medicines, oriented for the treatment of inflammation and pain. Boswellia serrata has been used since ancient times in China, Africa, India, and the Middle East for the prevention and treatment of several illnesses.
2.3 Religious and Ceremonial Use
The resin of Boswellia species has been used as incense in religious and cultural ceremonies and in medicine since time immemorial. The resin obtained from these trees has been traded for centuries along ancient trade routes and continues to be valued in various industries, including perfumery, traditional medicine, and religious rituals.
2.4 Traditional Therapeutic Preparations and Indications
It has astringent and antiseptic properties and is described as useful in diarrhea, dysentery, piles, ulcers, tumor, skin diseases, and genitourinary affections. Topical balms, decoctions, medicated ghee, and powdered resin mixed with warm water have all been recorded as traditional preparation forms.
3. Key Constituents and Active Compounds
3.1 Major Boswellic Acids
The main four triterpene acids include β-boswellic acid (β-BA), acetyl-β-boswellic acid (ABA), 11-keto-β-boswellic acid (KBA), and 3-O-acetyl-11-keto-β-boswellic acid (AKBA). Boswellic acid is a pentacyclic triterpene with strong anti-inflammatory activity; the most important source is the extract of the gum resin of Boswellia serrata.
Boswellia extract contains essential oils, terpenoids, sugars and volatile oils, and prominently several pentacyclic triterpene acids such as beta boswellic acid.
3.2 AKBA: The Principal Bioactive Compound
3-O-Acetyl-11-keto-beta-boswellic acid (AKBA) is considered the boswellic acid with the strongest pharmacological activity; AKBA has a powerful inhibitory effect on 5-lipoxygenase (5-LOX). The anticancer effect targets multiple molecular pathways, including kinases, transcription factors, enzymes, receptors, growth factors, and other elements involved in cell survival and proliferation. This effect is attributed to boswellic acids, particularly AKBA, which plays a key role in mediating anticancer properties of Indian frankincense.
4. Mechanisms of Action
4.1 5-Lipoxygenase (5-LOX) Inhibition
Boswellic acids are specific, non-redox inhibitors of 5-lipoxygenase (5-LOX), an enzyme involved in arachidonic acid metabolism. Evaluations of the inhibitory effects of different boswellic acids on 5-LOX across various in vitro test systems, including purified 5-LOX enzyme, E. coli lysates, and neutrophils, found that both AKBA and KBA demonstrated strong inhibition of 5-LOX across all systems, while α-boswellic acid exhibited greater inhibitory activity than β-boswellic acid.
An important caveat exists regarding this mechanism's in vivo relevance: in the presence of albumin (10 mg/mL), the inhibitory effect of KBA on neutrophil 5-LOX was abolished, which may explain why KBA failed to inhibit 5-LOX product formation in human whole blood during in vitro assays.
4.2 NF-κB Pathway Inhibition
A well-known biological activity of boswellic acid is inhibition of kappa B kinases as the molecular target, with consequent inhibition of NF-κB activation and TNF-α release from activated monocytes. AKBA can potentiate apoptosis, inhibit invasion, and abolish osteoclastogenesis in different human cancer cell lines; the mechanism of these actions was found to be suppression of NF-κB and NF-κB-regulated gene expression.
4.3 Inhibition of Leukocyte Elastase and Complement
The mechanism behind boswellic acids also includes inhibition of 5-lipoxygenase and leukotriene synthesis, along with inhibition of leukocyte elastase. They show an anti-inflammatory effect via inhibition of the complement system and the inhibition of 5-lipoxygenase.
4.4 Matrix Metalloproteinase (MMP) Inhibition and Cartilage Effects
The molecular mechanism of boswellic acid includes the inhibition of MMP transcription in fibroblasts and endothelial cells. Some evidence has suggested that the acids may have disease-modifying effects, thereby decreasing glycosaminoglycan degradation and cartilage damage.
4.5 Topoisomerase Inhibition
The mechanisms of activity of boswellic acids comprise a variety of targets, including enzymes of angiogenesis and others such as topoisomerases, 5-lipoxygenase (5-LO), cytochrome P450, and mitogen-activated protein kinase (MAPK, especially p38), which are either promoted or inhibited by boswellic acids. Certain boswellic acids also inhibit elastase in leukocytes, inhibit proliferation, induce apoptosis, and inhibit topoisomerases in cancer cell lines.
4.6 HIF-1α and VEGF Inhibition
AKBA is a potent inhibitor of hypoxia-inducible factor (HIF)-1α, which results in downstream inhibition of vascular endothelial growth factor (VEGF) expression and reduction in brain edema.
4.7 Intestinal Barrier Protection
H₂O₂ or IFN-γ+TNF-α treatment of intestinal cell monolayers significantly reduced transepithelial electrical resistance and caused disassembly of tight junction proteins occludin and ZO-1; both Boswellia serrata extract and AKBA pretreatment significantly prevented these functional and morphological alterations, as well as NF-κB phosphorylation induced by inflammatory stimuli, and counteracted the increase of reactive oxygen species caused by H₂O₂ exposure.
5. Scientific Evidence by Area of Use
5.1 Osteoarthritis
The strongest clinical evidence for Boswellia serrata is in osteoarthritis. A meta-analysis obtained data from randomized controlled trials to assess the effects of Boswellia or its extract versus placebo or western medicine in patients with osteoarthritis (OA). The primary outcomes included visual analogue score (VAS), WOMAC pain, WOMAC stiffness, WOMAC function, and Lequesne index. Seven trials involving 545 patients were included.
Compared with the control group, Boswellia and its extract may relieve pain (VAS: WMD −8.33; 95% CI −11.19 to −5.46; P<0.00001; WOMAC pain: WMD −14.22; 95% CI −22.34 to −6.09; P=0.0006) and stiffness (WOMAC stiffness: WMD −10.04; 95% CI −15.86 to −4.22).
An individual clinical trial specifically cited in multiple reviews was the Kimmatkar et al. (2003) crossover design: 30 patients with osteoarthritis of the knee — 15 each receiving active Boswellia serrata extract or placebo for eight weeks — were assessed; patients receiving the extract reported a decrease in knee pain, increased knee flexion, and increased walking distance.
In a randomized, placebo-controlled clinical study (N=80), a proprietary, standardized Boswellia serrata gum resin extract significantly improved joint pain, musculoskeletal function, and cartilage morphology after 180 days of supplementation in adult volunteers with knee osteoarthritis.
The benefits appear to build over time. At four weeks, pain scores improved modestly; by eight weeks, the improvement roughly doubled.
Evidence strength: Moderate to moderately strong. Multiple small-to-medium RCTs and one meta-analysis of 545 patients support consistent improvements in pain and function with few serious adverse events. Limitations include small individual trial sizes, heterogeneous extract formulations, and inconsistent standardization of boswellic acid content.
5.2 Inflammatory Bowel Disease: Ulcerative Colitis and Crohn's Disease
A 1997 study compared experiences of people with ulcerative colitis who took a Boswellia serrata gum resin preparation three times a day to others who took sulfasalazine three times a day. Participants who took the boswellia preparation saw improvements in a number of test results; after six weeks, 82 percent of those treated with the boswellia preparation achieved remission, while 75 percent of those on sulfasalazine achieved remission.
One notable study involving patients with ulcerative colitis found that those receiving Boswellia extract showed significant improvement in disease symptoms compared to the placebo group; the study reported a reduction in stool frequency, rectal bleeding, and mucosal inflammation as assessed by endoscopy.
Another trial focusing on Crohn's disease demonstrated that Boswellia extract was as effective as the standard drug mesalazine in maintaining remission, with fewer side effects. Out of 83 patients with Crohn's disease — 44 treated with H15 and 39 treated with mesalazine — Crohn Disease Activity Index between enrollment and end of therapy was reduced by 90 scores after treatment with H15 and by 53 scores after therapy with mesalazine, in the mean.
However, a more rigorously conducted large trial yielded conflicting results: in 22 German centers, a double-blind, placebo-controlled, randomized, parallel study was performed in 108 outpatients with Crohn's disease in clinical remission, randomized to Boswelan (3×2 capsules/day; 400 mg each) or placebo for 52 weeks; the primary endpoint was the proportion of patients in whom remission was maintained throughout the 52 weeks. The trial was prematurely terminated due to insufficient discrimination of drug and placebo with regard to the primary efficacy endpoint. The trial confirmed good tolerability of a new Boswellia serrata extract (Boswelan) in long-term treatment of Crohn's disease; however, superiority versus placebo in maintenance therapy of remission could not be demonstrated.
Twenty patients with chronic colitis given a preparation of the gum resin of Boswellia serrata (900 mg daily divided in three doses for 6 weeks) showed that 18 patients demonstrated improvement in more than one parameter, including stool properties and histopathology.
Evidence strength: Preliminary to moderate. Earlier small trials showed positive results versus active comparators, but the larger placebo-controlled Boswelan trial failed to demonstrate efficacy in Crohn's remission maintenance. Evidence for ulcerative colitis is more encouraging but still limited by small sample sizes.
5.3 Bronchial Asthma
Bronchial asthma was reduced in 70% of 40 patients treated with gum resin at 300 mg three times daily for 6 weeks in a double-blind trial (Gupta et al., 1998).
A few small studies suggest that taking boswellia orally may reduce asthma symptoms; however, there is not enough rigorous evidence to determine whether boswellia is a useful treatment for asthma. This assessment is from NCCIH (NIH's National Center for Complementary and Integrative Health).
Evidence strength: Preliminary. One positive double-blind RCT exists, but the trial is small, and regulatory-level systematic review bodies have concluded the evidence base is insufficient to confirm efficacy.
5.4 Rheumatoid Arthritis
Usage of NSAIDs declined 5.8% in the Boswellia group versus 3.1% in the placebo group, but no other benefit was noted in a study with 78 rheumatoid arthritis outpatients taking 9 tablets (3,600 mg) of Boswellia or placebo daily (Sander 1998).
Evidence strength: Weak. Available human trial data have not demonstrated robust clinically meaningful benefit for rheumatoid arthritis specifically; the evidence base is considerably weaker here than for osteoarthritis.
5.5 Radiation-Induced Cerebral Edema
To investigate the activity of Boswellia serrata in radiotherapy-related edema, a prospective, randomized, placebo-controlled, double-blind pilot trial was conducted in which 44 patients with primary or secondary malignant cerebral tumors were randomly assigned to radiotherapy plus either BS at 4,200 mg/day or placebo; the volume of cerebral edema in T2-weighted MRI was analyzed as the primary endpoint.
Compared with baseline, a reduction of cerebral edema of >75% was found in 60% of patients receiving Boswellia serrata. A correlation of edema reduction with serum levels of boswellic acids was reported — in patients with the highest Boswellia serum levels, the largest edema reduction was observed.
There has been limited research in people on taking boswellia orally for several types of cancer, and although some results are encouraging, larger clinical studies are needed. A small study of patients with malignant glioma showed that boswellia taken orally may help to reduce edema of the brain but not the tumor.
Evidence strength: Preliminary. One small randomized pilot trial has yielded promising results, and the mechanistic rationale (HIF-1α and VEGF inhibition) is plausible, but the study was a pilot, and the patient population was small. Larger confirmatory trials are needed.
5.6 Irritable Bowel Syndrome (IBS)
A lecithin-based formulation of Curcuma longa and Boswellia serrata extracts adjunct to a low-FODMAP diet significantly reduced small bowel dysbiosis, abdominal pain, and bloating in subjects (N=49) with irritable bowel syndrome, compared with the low-FODMAP diet alone (Giacosa 2024).
Evidence strength: Very preliminary. A single combination-product trial in a small population, confounded by the presence of curcumin and dietary intervention. No standalone evidence for Boswellia serrata in IBS is yet established.
5.7 Cognitive Function
In a randomized, double-blind study, supplementation for 120 days significantly improved cognitive function, sleep quality, and peripheral brain-derived neurotrophic factor (BDNF) levels in aging adults with subjective memory complaints.
Evidence strength: Very preliminary. Single trial, with the full independent replication record not yet established.
5.8 Anticancer Effects (Preclinical Focus)
Several scientific studies have shown Boswellia's pentacyclic triterpenes as one of the most promising anti-cancer agents in preclinical research. AKBA and KBA have been assessed by active inhibition of topoisomerase I and IIα, which restricts the growth of cells. These findings are predominantly from cell-culture and animal models. There has been limited research in people on taking boswellia orally for cancer, and although some results are encouraging, larger clinical studies are needed.
Evidence strength: Mechanistically compelling in vitro and animal data only; robust human clinical evidence for direct anticancer efficacy is absent.
6. Body Systems and Health Areas of Association
- Musculoskeletal system: Osteoarthritis (strongest clinical evidence); rheumatoid arthritis (limited evidence)
- Gastrointestinal system: Ulcerative colitis, Crohn's disease, chronic colitis, IBS (mixed or preliminary evidence)
- Respiratory system: Bronchial asthma (preliminary positive evidence)
- Central nervous system: Cerebral edema from radiation therapy (preliminary pilot evidence); cognitive function (single trial)
- Oncology (adjunctive): Radiation-related brain edema; extensive preclinical anticancer data without confirmed human efficacy
- Immune system: Immunomodulation via NF-κB, cytokine modulation, and leukotriene suppression (primarily in vitro and animal)
7. Dosage Forms and Study Dosages
Boswellia serrata extract in doses up to 1,000 mg daily has been safely used in several clinical trials lasting up to 6 months. It has also been used with apparent safety at a dose of 2,400 mg for up to 1 month.
Study-specific dosages reported in the literature include the following:
- Bronchial asthma (Gupta 1998): gum resin 300 mg three times daily for 6 weeks.
- Chronic colitis: gum resin 900 mg daily divided in three doses for 6 weeks.
- Crohn's disease maintenance (Boswelan trial): 3×2 capsules/day at 400 mg each (total 2,400 mg/day) for 52 weeks.
- Cerebral edema in brain tumor radiotherapy (Kirste 2011): 4,200 mg/day.
- Adverse radiation effects case series (5-Loxin): 150 mg twice a day with a fatty snack to enhance absorption.
- Osteoarthritis studies: symptomatic improvements have been reported with doses up to 6 g of B. serrata of undetermined β-boswellic acid composition.
Regarding bioavailability and food effects: an extreme increase in bioavailability — with 387% higher plasma concentration over time — was reported if boswellic acids were taken with a fatty meal. There are several commercial preparations of Boswellia available, and the concentration of the active component AKBA may not be uniform across preparations; factors affecting the bioavailability of boswellic acids are also poorly defined.
Clinical research specifically targeting isolated boswellic acids remains limited and relatively underdeveloped. Most published RCTs have investigated Boswellia serrata extracts as the intervention; these extracts often contain a complex mixture of multiple boswellic acids along with various resinous and volatile metabolites. The precise content of boswellic acids is frequently not standardized, nor is it specified which particular boswellic acid is responsible for observed activity.
8. Safety Profile and Notable Drug Interactions
8.1 General Tolerability
Boswellia serrata extract has not been linked to serum enzyme elevations during therapy. In small trials, boswellia extracts have appeared to be well tolerated with only minor and few adverse effects, which were similar in frequency among persons receiving placebo. Despite widespread use as an herbal supplement, boswellia extract has not been convincingly linked to published instances of clinically apparent liver injury.
Boswellia is typically referred to as generally safe when used as directed, with rare side effects such as diarrhea, skin rash, and nausea.
8.2 Gastrointestinal Adverse Effects
Common side effects include constipation, diarrhea, and an upset stomach.
8.3 Liver Safety
Boswellia is often included in multi-ingredient dietary supplements, some of which have been implicated in liver injury, but a specific contribution from boswellia to the injury could not be established. The frequency of hypersensitivity reactions to boswellia is also not known. LiverTox rates the likelihood score for boswellia causing clinically apparent liver injury as E (unlikely cause).
8.4 Drug Interactions: P-Glycoprotein and MRP2
Both KBA and AKBA modulated the activity of MRP2 (a multidrug-resistant protein) in vitro; clinical relevance is not known. A Boswellia extract and keto-boswellic acids inhibit the activity of P-Glycoprotein in vitro and may affect the transport of drugs mediated by this protein; clinical significance has yet to be determined.
8.5 Anticoagulant Interaction Risk
Boswellia extracts can inhibit platelet aggregation and may increase risk of bleeding when used with anticoagulant and/or antiplatelet drugs; clinical significance has yet to be determined.
8.6 Pregnancy
Boswellia may increase menstrual flow (emmenagogue) and induce miscarriage (abortifacient).
8.7 Limitations in Safety Knowledge
The reported doses of boswellia and their direct comparison across clinical models is complicated by the fact that methods used to obtain extracts and the composition of extracts are never disclosed, and are bound to vary greatly not only between manufacturers but also among lots. This heterogeneity fundamentally limits safety generalization across all commercial products.
References
- NIH/NLM LiverTox: Boswellia Serrata. NCBI Bookshelf.
- NCCIH (National Center for Complementary and Integrative Health): Boswellia: Usefulness and Safety.
- Siddiqui MZ. Boswellia Serrata, A Potential Antiinflammatory Agent: An Overview. PMC / Indian Journal of Pharmaceutical Sciences, 2011.
- Yu G, et al. Effectiveness of Boswellia and Boswellia extract for osteoarthritis patients: a systematic review and meta-analysis. BMC Complement Med Ther. 2020;20:225. PMC.
- Holtmeier W, et al. Randomized, placebo-controlled, double-blind trial of Boswellia serrata in maintaining remission of Crohn's disease: good safety profile but lack of efficacy. PubMed. Inflamm Bowel Dis. 2011.
- Kirste S, et al. Boswellia serrata acts on cerebral edema in patients irradiated for brain tumors: a prospective, randomized, placebo-controlled, double-blind pilot trial. Cancer. 2011;117(16):3788–3795.
- Iram F, et al. Anti-cancer properties of boswellic acids: mechanism of action as anti-cancerous agent. Frontiers in Pharmacology. 2023. PMC.
- PMC: From bench to bedside, boswellic acids in anti-inflammatory therapy — mechanistic insights, bioavailability challenges, and optimization approaches. PMC. 2025.
- Sailer ER, et al. Acetyl-11-keto-beta-boswellic acid (AKBA): structure requirements for binding and 5-lipoxygenase inhibitory activity. PMC / Br J Pharmacol. 1996.
- Catanzaro D, et al. Boswellia serrata Preserves Intestinal Epithelial Barrier from Oxidative and Inflammatory Damage. PMC. 2015.
- Warnick RE, et al. Treatment of adverse radiation effects with Boswellia serrata after failure of pentoxifylline and vitamin E: illustrative cases. PMC / J Neurosurg Case Lessons. 2023.
- Badria FA, et al. The Beneficial Effect of Boswellic Acid on Bone Metabolism and Possible Mechanisms of Action in Experimental Osteoporosis. PMC. 2020.
- Frankincense unveiled: Phytochemistry, bioactivity, and future directions. ScienceDirect. 2025.
- Majeed M, et al. A standardized Boswellia serrata extract shows improvements in knee osteoarthritis within five days. Frontiers in Pharmacology. 2024.
- Upadhyay R, et al. Boswellia serrata for the Management of Radiation-Induced Cerebral Edema and Necrosis: A Systematic Meta-Narrative Review. Advances in Radiation Oncology. 2025.
- Boswellia Serrata for Cerebral Radiation Necrosis After Radiosurgery for Brain Metastases. International Journal of Radiation Oncology Biology Physics. 2025.
- Memorial Sloan Kettering Cancer Center: Boswellia — Integrative Medicine Herb Information.
- HerbalGram / HerbMedPro: Boswellia serrata Clinical Trials database. American Botanical Council.
- Rjabovs V, et al. A 90-Day Gavage Safety Assessment of Boswellia serrata in Rats. PMC. 2012.
- Efficacy and Safety of Boswellia serrata and Apium graveolens L. Extract Against Knee Osteoarthritis and Cartilage Degeneration: A Randomized, Double-blind, Multicenter, Placebo-Controlled Clinical Trial. PMC. 2025.
- Majeed M, et al. Boswellia serrata Extract Containing 30% AKBA Attenuates Inflammatory Mediators in Collagen-Induced Arthritis. PMC. 2021.
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