Nurse Practitioner Advertising And Selling Mlm Products To Patients

Is it illegal for a nurse practitioner (specifically FNP-BC, PMHNP) to open a clinic (a psychiatry and wellness clinic) and advertise/sell MLM products to their patients? The products are Slenderiiz® Slenderiix™ & Xceler8™ (“skinny drops” that are not FDA approved). The clinic’s website does not mention them, but the clinic’s Facebook page and the clinician’s personal page is covered in posts emphasizing weight loss and promoting these products. If this is not legal, who would I contact to investigate? Thank you so much for any help you can provide.