People consumed tea leaves steemed in boiling water as many as 500,000 years ago. India and China were among the first countries to cultivate tea. Today, millions of people drink tea around the world and studies are now suggesting that green tea (Camellia sinensis) in particular has many health benefits. Green tea has the highest polyphenol content while black tea has roughly two to three times the caffeine content of green tea. take any healthy food excessively; it is likely to turn into a poison. Green tea contains active substances that can trigger side effects and interact with other supplements or medications. People should take green tea and green tea extracts with care to get its beneficial effects and to avoid its side effects. People with heart problems, kidney disorders, stomach ulcers, and psychological disorders (particularly anxiety) should not take green tea. Also pregnant women should avoid green tea.Key word:Green tea, green tea toxicity, green tea side effects, uses of green tea. Material and Methods : A total number of 140 adult male albino rats were included in this study. All animals were fed the same type of food to avoid the effect of diet on the experiments.. They had free access to water and kept at room temperature. The animals were divided into two main groups: Group A (Normal rats) , Group B (Streptozotocin –induced diabetic rats) . Each group was subdivided into four subgroups : Subgroup 1 : control group : injected with saline 0.5 ml i.v. in the tail vein ,Subgroup 2 : injected with Ghrelin 20µg /Kg i.v. ,Subgroup 3 : injected with Ghrelin 20µg /Kg i.v. + L-NAME 70 mg /Kg s.c.,Subgroup 4 : injected with L-NAME 70 mg /Kg ,Gastric secretions were collected and gastric secretion volume , both free and total acidity, pH were measured.Results :The study reported that ghrelin significantly enhanced the secretion of both gastric acid and mucus in both normal and diabetic rats,and these effects inhibited by the nitric oxide synthase inhibitor, L_NAME. Also, there was a significant reduction in gastric acid secretion in STZ – induced diabetic rats in comparison with that in normal rats.Conclusions : Ghrelin plays a stimulatory role on gastric acid secretion and mucus secretion in both normal and STZ-induced diabetic rats and the nitric oxide synthase inhibitor L-NAME blocks this effect. So, this role is performed via nitric oxide as a mediator.