Boswellia

The hardened gum resin of Boswellia serrata, a scrubby tree that grows in the dry hills of India — the same genus that gives frankincense, which is why the trade calls it Indian frankincense. The resin is tapped from cuts in the papery bark, dried, and extracted for its boswellic acids.

The textbook answer is 5-lipoxygenase. Boswellic acids — AKBA in particular — block that enzyme in a test tube, which is a different pathway from the COX route that aspirin and ibuprofen work on. The honest footnote is that the concentrations needed in vitro (roughly 1.5 to 50 µM, depending on the assay) are higher than an oral dose reliably puts in human blood, and the step has never been confirmed in a living person. Later work points at other targets — microsomal prostaglandin E synthase-1 and cathepsin G — and at beta-boswellic acid as much as AKBA. Real pharmacology, unsettled mechanism. Absorption is the other problem, and the one you can do something about: in healthy volunteers, 786 mg of extract taken with a high-fat meal produced several times the plasma boswellic acid levels of the same dose taken fasted.

Used to support normal joint comfort and mobility, and studied for its effect on normal inflammatory balance.

Men doing long-term joint maintenance who want the botanical with the best paperwork in the category, and who can live with the paperwork being thin. Not for anyone taking warfarin, a DOAC, clopidogrel or regular NSAIDs without a doctor's sign-off, not in pregnancy or breastfeeding, not in the run-up to surgery, and not for anyone hoping to replace a medicine they have been prescribed.

Two capsules daily with food, and preferably food with some fat in it — meal versus no meal is the one variable shown to change how much reaches your blood. Same time each day, and give it at least four weeks: every trial that found anything ran a month or longer. If you take a blood thinner, tell your doctor before you start rather than after.

Slow, if anything. The trial measurements came at days 7, 30, 60 and 90, and what benefit there was accumulated across that window rather than arriving. At the end it amounted to a modest, self-reported improvement in comfort and function — not the disappearance of stiffness. Judge it at twelve weeks or not at all, and set the expectation below the trial numbers, because the trials used an extract specified differently from this one.

Cochrane's 2014 review of oral herbal therapies for osteoarthritis (Cameron and Chrubasik, CD002947) found moderate-quality evidence from two studies and 85 participants that 100 mg a day of an enriched Boswellia serrata extract for 90 days reduced pain by a mean 17 points on a 0–100 VAS (95% CI 8 to 26) against placebo, with a smaller and less certain improvement of about 8 points in physical function. In one 96-participant study adverse events were probably lower with boswellia than placebo (18 events versus 30). A 2020 meta-analysis in BMC Complementary Medicine and Therapies (Yu et al.) pooled seven RCTs and 545 patients and reported reductions in VAS pain (WMD −8.33, 95% CI −11.19 to −5.46), WOMAC pain (−14.22, 95% CI −22.34 to −6.09), stiffness (−10.04, 95% CI −15.86 to −4.22) and function (−10.75, 95% CI −15.06 to −6.43), while rating trial quality medium to low and advising cautious interpretation. NCCIH's position is that there is not enough high-quality evidence to determine whether boswellia is useful for any health condition, and that extract doses up to 1,000 mg a day have been used safely in trials lasting up to six months (2,400 mg for up to a month). The trial extracts were AKBA-enriched: 5-Loxin at 30% AKBA (Sengupta 2008, 75 patients at 100 mg or 250 mg for 90 days) and Aflapin at about 20% (Sengupta 2010, 60 patients). The older unenriched work (Kimmatkar 2003, Phytomedicine) used 333 mg three times daily in a 30-patient crossover trial over eight weeks. On mechanism, boswellic acids inhibit 5-lipoxygenase in vitro at IC50 values of roughly 1.5–50 µM with no in vivo confirmation, and later work implicates microsomal prostaglandin E synthase-1 and cathepsin G. On absorption, Sterk 2004 found several-fold higher plasma boswellic acids when 786 mg of extract was taken with a high-fat meal rather than fasted. Not supported: any claim that boswellia treats, prevents or cures arthritis or any other disease, or repairs cartilage in humans.