Curcumin and Boswellia in Inflammatory Disorders: Immune Mechanisms, Bioavailability and Dose Comparability

Background/Objectives: Curcumin and Boswellia preparations have been investigated for anti-inflammatory and immunomodulatory effects, but clinical translation is complicated by differences in composition, formulation and exposure. This narrative review examines mechanisms, pharmacokinetics and clinical evidence across immune-mediated, degeneration-associated and acute systemic inflammatory disorders, emphasizing dose comparability. Methods: Literature was identified through iterative PubMed searches and reference list screening, prioritizing recent systematic reviews and meta-analyses and selected primary clinical and pharmacokinetic studies. Experimental pathway effects, human biomarker changes and patient-relevant outcomes were evaluated separately. Results: Clinical findings suggest potential adjunctive symptomatic benefits, with a comparatively larger evidence base in knee osteoarthritis; findings in other indications remain heterogeneous, inconsistent or limited. Differences in active constituents, delivery technology and administered doses restrict comparisons across preparations. Higher systemic exposure does not by itself establish greater clinical efficacy, and neither pharmacokinetic bioequivalence nor clinically equivalent doses have generally been established across formulations. Local gastrointestinal effects and tissue distribution may also contribute to clinical outcomes. Interpretation is further constrained by small trials, overlapping evidence sources and reported industry relationships. Safety considerations include idiosyncratic liver injury associated with turmeric/curcumin products and potential drug interactions. Conclusions: Curcumin and Boswellia preparations show potential as adjunctive interventions, but formulation heterogeneity and limitations of the clinical evidence preclude general assumptions of interchangeability or clinical superiority based on increased bioavailability. Future research should prioritize formulation-specific human pharmacokinetics, dose-finding and adequately powered, independently replicated clinical trials, including direct comparisons where appropriate.