Short answer: L-Citrulline and nitric oxide, Pine bark extract and vascular function, and Nattokinase and circulation are PubMed citations, alongside NIH ODS and FDA general dietary supplement information — five specific, independent sources worth checking directly.
Why five distinct sources, not one blanket citation, are listed
Three ingredient-specific PubMed searches plus two general regulatory resources reflect a genuinely thorough, layered approach to sourcing.
Why the site directly clarifies what these citations do and don't prove
These citations refer to research on the individual ingredients, not the finished Boostaro product, which has not been the subject of its own clinical trial — a direct, honest distinction worth applying to each source.
💡 Worth knowing: checking the NIH and FDA general resources is worth doing even beyond this specific product, for understanding dietary supplements broadly.