**5.3.18 Cistanche total glycosides (CTGs)**

The glycosidic extract of the plant *Cistanche spp.* has a long tradition in its medicinally use in Traditional Chinese Medicine (TCM). It has been described as a neuroprotective agent in a mouse model of Parkinson's Disease (PD) (Li et al., 2008). Currently, Cistanche Total Glycosides are investigated in a phase II trial (NCT00753571). Of note, the CTGs are the only agents in registered ALS trials without a defined chemical composition, which may impose problems in future comparability to other medications and effectiveness of different preparations.
