Benefits
Knee joint pain and stiffness, studied in adults with knee osteoarthritis
A meta-analysis of 7 randomized trials in 545 people with osteoarthritis found that boswellia, alone or combined with ingredients such as curcumin or MSM, eased pain and stiffness and improved function compared with placebo or standard treatments, with at least 4 weeks of use recommended. The trials were small, and two of the three placebo-controlled trials cited here were run by the extract maker.
Knee swelling and joint-fluid enzyme changes, studied in knee osteoarthritis
In a crossover trial in 30 people with knee osteoarthritis, knee swelling was less frequent with boswellia extract than with placebo. In a 90-day trial of the 5-Loxin extract in 75 people, MMP-3, an enzyme that breaks down cartilage, fell in joint fluid. Both trials were small, and no cited human study measured blood inflammation markers such as CRP.
Branded AKBA-enriched extracts 5-Loxin and Aflapin
5-Loxin is enriched to 30% AKBA, and Aflapin is a related composition from the same maker. In a 90-day trial in 60 people with knee osteoarthritis, 100 mg a day of either beat placebo for pain and function, with Aflapin improving from day 7. No cited trial compared enriched extracts with ordinary boswellia extracts.
Tolerability in the trials
Boswellia was generally well tolerated in the trials cited here, which enrolled 30 to 75 people each for up to 90 days, with minor digestive side effects in one trial. A network meta-analysis found no increase in adverse events versus placebo. Rarer or slower-developing side effects could have been missed, and use beyond 3 months was not tested.
Mechanism of action
5-lipoxygenase inhibition
AKBA, the main boswellic acid in enriched extracts, is reported to inhibit 5-lipoxygenase, an enzyme in the body's inflammation pathway. This comes from laboratory research described by the extract makers; no cited human study measured 5-lipoxygenase activity.
Lower cartilage-degrading enzyme in joint fluid
In the 90-day 5-Loxin trial, MMP-3, an enzyme that breaks down cartilage, fell in the joint fluid of treated people, and the same group's lab work found Aflapin inhibits MMP-3. Cartilage itself was not measured, so this does not show joint protection.
Clinical trials
Systematic review and meta-analysis of 7 randomized controlled trials of Boswellia serrata or its extracts versus placebo or standard drugs in osteoarthritis; outcomes were VAS pain, WOMAC pain, stiffness and function and the Lequesne index (Yu et al. 2020, BMC Complement Med Ther)
545 people with osteoarthritis across 7 trials.
Boswellia lowered VAS pain (WMD -8.33, 95% CI -11.19 to -5.46) and improved WOMAC pain, stiffness and function and the Lequesne index compared with control. The authors recommended at least 4 weeks of use. The trials were small, four of the seven tested boswellia combined with other ingredients such as curcumin or MSM, two compared it with ibuprofen or glucosamine rather than placebo, and two were run by the maker of 5-Loxin and Aflapin.
Randomized, double-blind, placebo-controlled trial of 5-Loxin (30% AKBA) at 100 or 250 mg a day for 90 days (Sengupta et al. 2008, Arthritis Res Ther)
75 adults with knee osteoarthritis (25 per group); 70 completed.
Both doses improved pain and physical function scores versus placebo, with the 250 mg dose improving by day 7. MMP-3, a cartilage-degrading enzyme, fell in joint fluid. Safety tests were similar to placebo. The researchers worked for Laila Impex, which makes 5-Loxin.
Randomized, double-blind, placebo-controlled trial of 100 mg a day of 5-Loxin or Aflapin for 90 days (Sengupta et al. 2010, Int J Med Sci)
60 adults with knee osteoarthritis (20 per group); 57 completed.
Both extracts improved pain and physical function versus placebo, and Aflapin improved by day 7. Safety tests were similar to placebo. The researchers worked for Laila Impex, which makes both extracts.
Randomized, double-blind, placebo-controlled crossover trial of a Boswellia serrata extract, 8 weeks per treatment with a washout between (Kimmatkar et al. 2003, Phytomedicine)
30 people with knee osteoarthritis.
During boswellia treatment, knee pain decreased, knee flexion and walking distance increased, and knee swelling was less frequent, with significant differences from placebo. X-rays showed no change. Minor digestive side effects were reported.