Just wade through the threads on Herbals, the Phoenix project, Puria Mirofica and shrinking willy, and save your cash. Those that have done it the ''right way'' medically supervised will say yes, those promoting and selling herbal remedies will also say yes. As to your last point how to talk about it, did you know your GF had already had a ''bad'' experience of being deceived, bit late in the day now you have been caught out. She will be upset. feeling somewhat paranoid and deceived. a here we go again scenario!
there is the Significant others forum where she can get support and understanding for the condition.