I've been looking in to plexus products. not for weight loss, i'm mainly interested in their probiotic and their vitamin supplements. any advice?

Dietary supplements: FDA monitors both prescription & over-the-counter medications. This means that companies must prove both safety & effectiveness of their medications before they can market them. OTOH, manufacturers of dietary supplements have no legal obligation to prove either safety or effectiveness prior to marketing. So long as put FDA disclaimer on product, they can make up wild claims & miraculous promises.