Acacia rigidula – also known as Vachelia rigidula, Chaparro Prieto, and blackbrush – is an ingredient found in weight loss and bodybuilding supplements.  FDA has taken the position that it is a “new dietary ingredient” (NDI), and that there is no evidence that it may be lawfully marketed as such.  To sell an NDI, the ingredient must have been present in food, or it must have been the subject of a notification submitted to FDA showing a reasonable expectation of safety.  In March, FDA sent warning letters to six companies selling products containing Acacia rigidula.  The warning letters stated that “[f]ailure to immediately cease distribution of your product . . . and any other products you market that contain A. rigidula could result in enforcement action by FDA without further notice.”