The World Health Organization (WHO) has developed guidelines to provide guidance on selection of medicines for treatment intensification in type 2 diabetes (T2D) and on use of insulin in type 1 and 2 diabetes. The recommendations were formulated by a 12-member guideline development group and are based on high-quality systematic reviews from January 1, 2007 to March 2017. The recommendations include:

• Give a sulfonylurea to patients with T2D who do not achieve glycemic control with metformin alone or who have contraindications to metformin (strong recommendation, moderate-quality evidence).
• Introduce human insulin treatment to patients with T2D who do not achieve glycemic control with metformin and/or a sulfonylurea (strong recommendation, very-low-quality evidence).
• If insulin is unsuitable, a dipeptidyl peptidase-4 (DPP-4) inhibitor, a sodium–glucose cotransporter-2 (SGLT-2) inhibitor, or a thiazolidinedione (TZD) may be added (weak recommendation, very-low-quality evidence).
• Use human insulin to manage blood glucose in adults with type 1 diabetes and in adults with T2D for whom insulin is indicated (strong recommendation, low-quality evidence).
• Consider long-acting insulin analogues to manage blood glucose in adults with type 1 or T2D who have frequent severe hypoglycemia with human insulin (weak recommendation, moderate-quality evidence for severe hypoglycemia).