This book will be very helpful for researcher for the treatment work of diabetes & related research work. Sitagliptin is a drug of class DPP-IV inhibitors, therapeutic dose administered for a long time, in response to a report of precancerous changes in the pancreases of rats & organ donors treated with the DPP-IV inhibitor sitagliptin. The main objective of this study was to improve the biological activity with minimum side effects by using sub therapeutic dose of Sitagliptin with guggul sterones in streptozotocin induced diabetic rat models. An animal trial was carried out using the drug Sitagliptin low therapeutic dose, co-administered with sub-therapeutic dose of Guggul Sterones by using albino wistar rats, in different dose levels observed the toxicity and antidiabetic activity. The author hopes that this book will prove to be very important and useful for readers and researchers in the field of pharmacology & toxicology.