Frankincense (Boswellia)

What it is

Boswellia serrata is a tree from India; its dried gum resin is Indian frankincense. In Ayurvedic medicine it is traditionally used for inflammatory complaints and painful joints. As a food supplement it usually comes as a dry extract in capsules or tablets.

The active compounds attributed to the resin are the boswellic acids. There are six typical ones, the best known being AKBA. Special extracts such as 5-Loxin or Aflapin are specifically enriched with AKBA, and most osteoarthritis studies were carried out with exactly such extracts. This matters: any frankincense powder is not the same product as the one used in the studies.

How it is supposed to work

In the laboratory, boswellic acids act at two points in inflammation. They inhibit 5-lipoxygenase, the key enzyme for the formation of leukotrienes, and AKBA is the most potent inhibitor among the natural boswellic acids. They also bind the prostaglandin E2 synthase mPGES-1 and thus slow the formation of the inflammatory messenger PGE2, without blocking the other prostaglandins as classic painkillers do. This effect could be demonstrated in human whole blood.

What remains open is how much of it reaches the body. Blood levels after intake are often below the concentrations that are effective in the laboratory, and they vary widely between people. A high-fat meal makes a big difference: in a study with healthy men, blood levels of the most important boswellic acids rose several-fold with fat compared with intake on an empty stomach. Researchers explain the fact that frankincense nevertheless has a clinical effect by tissue levels and the interplay of several constituents, but this has not been measured in humans.

What users are looking for

Most people reach for frankincense because of knee or hip complaints, often because they do not want to take painkillers such as ibuprofen long term. Others use it for chronic inflammatory bowel diseases, asthma or after sports injuries. Many report less morning stiffness and better mobility after a few weeks. These are user reports that match the study situation in osteoarthritis, but for the other uses go beyond what has been tested in controlled studies. Frankincense is often combined with turmeric, whose benefit in knee osteoarthritis has also been studied.

What the studies show

The 5-Loxin study

75 people with knee osteoarthritis received 100 mg or 250 mg of the AKBA-enriched extract 5-Loxin or placebo for 90 days; 70 completed the study. Both doses clearly improved pain and function, the higher one after just 7 days. In the synovial fluid, the cartilage-degrading enzyme MMP-3 also decreased. Several authors worked for the manufacturer, which the Drug Commission of the German Medical Association explicitly notes.

The cerebral edema study

44 patients with brain tumors received 4,200 mg of frankincense per day or placebo during radiotherapy. A reduction in cerebral edema of more than 75 percent was seen in 60 percent under frankincense and 26 percent under placebo. There were no serious side effects; quality of life and cognition did not change. The European Medicines Agency had already designated frankincense extract as an orphan medicinal product for this use in 2002; a larger confirmatory study is still missing today.

The Crohn’s study

In 22 German centers, the extract Boswelan was to prevent relapses of Crohn’s disease over 52 weeks. The study was stopped early because the active substance and placebo hardly differed: 59.9 percent versus 55.3 percent remained in remission. Tolerability over one year, on the other hand, was good.

Where the data stop

The osteoarthritis studies are small and short. In 2017, the Drug Commission of the German Medical Association counted four placebo-controlled studies from India with an average of 22 patients per group; none ran longer than half a year, and in two of them manufacturer employees were authors. A 2018 meta-analysis calls the study quality low overall; a 2024 meta-analysis found no significant effect overall because of the large differences between the studies, only in the comparison with placebo. There is no direct comparison with approved painkillers such as ibuprofen, and nobody has measured on X-rays whether frankincense protects cartilage.

Then there is the product question. The results apply to a few special extracts. An investigation of 17 frankincense products from Europe and the US found that 41 percent did not match their label; one Italian product contained not a single one of the typical boswellic acids. In chronic inflammatory bowel diseases the picture is inconsistent: no effect on maintenance of remission in Crohn’s disease, a signal in collagenous colitis that was significant only in the per-protocol analysis. On blood sugar and blood lipids there is a meta-analysis of 5 small studies; on sports injuries there are no reliable data.

Status, approval and legal

In Germany, frankincense is not an approved medicine, apart from one homeopathic product. It is sold as a food supplement. In the substance list of the Federal Office of Consumer Protection and Food Safety (BVL), the resin of Boswellia serrata is classified as not novel in food supplements, so no novel food authorization is required. There are no authorized health claims, and advertising with healing effects is not permitted. In 2002, the EMA designated frankincense extract as an orphan medicinal product for cerebral edema in tumors; it is not approved for this. There are no maximum levels from EFSA, BfR or DGE. Frankincense is not on the 2026 WADA Prohibited List.

Safety

In studies, frankincense is considered well tolerated. The most common complaints are mild, transient gastrointestinal symptoms such as nausea, diarrhea or constipation, plus heartburn and allergic reactions. LiverTox lists frankincense with the score E, i.e. as an unlikely cause of clinically relevant liver injury. Caution applies with anticoagulants: the German consumer advice center (Verbraucherzentrale) advises against combining it with drugs such as warfarin, and in the laboratory boswellic acids affect blood platelets in an inhibiting or promoting way depending on their structure. Reliable data are lacking for pregnancy, breastfeeding and children. Anyone with a chronic inflammatory disease should not take frankincense instead of a prescribed therapy.

Sources

• Cameron and Chrubasik, Cochrane Database Syst Rev 2014 – oral herbal therapies for osteoarthritis
• Yu et al., BMC Complement Med Ther 2020 – meta-analysis of Boswellia in osteoarthritis
• Zhang et al., Nutrients 2025 – network meta-analysis of supplements in knee osteoarthritis
• Sengupta et al., Arthritis Res Ther 2008 – 5-Loxin in knee osteoarthritis
• Kirste et al., Cancer 2011 – Boswellia for cerebral edema during radiotherapy
• Holtmeier et al., Inflamm Bowel Dis 2011 – Boswellia for maintenance of remission in Crohn’s disease
• Siemoneit et al., Br J Pharmacol 2011 – inhibition of mPGES-1 by boswellic acids
• Meins et al., Planta Med 2016 – quality of frankincense food supplements
• Steinmeyer, Arzneiverordnung in der Praxis 2017 – frankincense for the treatment of osteoarthritis
• LiverTox (NIH) – Boswellia serrata