The Federal Food, Drug and Cosmetic Act does not preempt state law requirements for dietary supplements that do not differ from those promulgated under the FDCA. So a plaintiff can bring a UCL action against a dietary supplement supplier for failing to substantiate its advertising or labeling claim about the supplement’s structure or function–except that while the FDCA and FDA regulations place the burden on the supplier to substantiate those claims, the plaintiff bears the initial burden under California law.  The district court erred in thinking Dachauer v. NBTY, Inc. (9th Cir. 2019) 913 F.3d 844 held that the FDCA preempted all state law claims that structure/function claims were unsubstantiated.  Instead, Dachauer held only that the FDCA preempted the claim if the plaintiff tried to disprove the supplier’s substantiation of a structure/function claim (promotes heart health) with proof that the supplement did not prevent disease.  Disease claims are separately regulated by the FDA.  So the mismatch of structure/function claim with disease proof represented a departure from FDA standards that federal law preempted.  Here, however, the complaint alleged that the claim that the supplement promoted joint health was unsubstantiated because scientific studies showed it did not do so.  That “matching” structure/function proof was not preempted by federal law.  Also, Dachauer was decided on summary judgment; whereas, here the complaint was dismissed before plaintiff could conduct discovery or present proof that contradicted defendant’s substantiation of its structure/function claim.  The district court also erred in denying plaintiff leave to amend to allege evidence outside the product label itself to show that in context the label’s statement’s impliedly made a disease claim governed by a different, stricter FDA standard.