TLIK, do you mean kashrus-wise, or are you questioning if there might be a different reason not to take them?
I found these about homeopathic remedies:
http://www.hebrewbooks.org/pdfpager.aspx?req=27996&st=&pgnum=34&hilite=
http://www.hebrewbooks.org/pdfpager.aspx?req=1600&st=&pgnum=432&hilite=
http://www.hebrewbooks.org/pdfpager.aspx?req=1415&st=&pgnum=53&hilite=