Prescription omega-3 fatty acid products and dietary supplements are not interchangeable

Purpose: To provide an overview of prescription and dietary supplement omega-3 fatty acid (OM3-FA) products and considerations for clinical use. Design: Narrative review. Methodology: The PubMed database was searched for cardiovascular-related investigations focused on eicosapentaenoic acid (EPA) and/or docosahexaenoic acid (DHA) (limit: English-only articles). Additional regulatory information on prescription and dietary supplements was obtained from United States Food and Drug Administration online sources. Results: Prescription OM3-FA products are supported by robust clinical development and safety monitoring programs, whereas dietary supplements are not required to demonstrate safety or efficacy prior to marketing. There are no over-the-counter OM3-FA products available in the United States. Investigations of OM3-FA dietary supplements show that quantities of EPA and DHA are highly variable within and between brands. Dietary supplements also may contain potentially harmful components, including oxidized OM3-FA, other lipids, cholesterol, and toxins. Prescription OM3-FA products may contain DHA and EPA or EPA alone. All prescription OM3-FA products have demonstrated statistically significant triglyceride reduction as monotherapy or in combination with statins in patients with hypertriglyceridemia. Differential effects between products containing EPA and DHA compared with a high-purity EPA product (icosapent ethyl) have clinical implications: Increases in low-density lipoprotein cholesterol associated with DHA have the potential to confound strategies for managing patients with dyslipidemia. Cardiovascular outcomes studies of prescription OM3-FA products are ongoing. Conclusions: OM3-FA dietary supplements should not be substituted for prescription products, and prescription OM3-FA products that contain DHA are not equivalent to or interchangeable with high-purity EPA (icosapent ethyl) and should not be substituted for it.