Injection sclerotherapy for all grades of interhemorrhoids in various situations and co-morbidities has become popular method of treatment. Several types of surgical operations both conventional and stapled hemorrhoidectomy has many and serious described side effects. On the contrary, proctoscopic injection sclerotherapy using some of the modern sclerosants and thin bore needle injections is an office-based ambulatory method of treatment of internal hemorrhoids; it is low in cost, devoid of any major complications besides it is quite successful as reported. Its safety and efficacy has been published in recent years. This manuscript is a result of thorough systemic review using PRISMA guidelines on various sclerosing agents, their merits and demerits, methods of administration, and outcome in internal hemorrhoids.