The aim of this trial is to evaluate the safety and tolerability of the study drug known as LY3374849, when given as an injection to healthy participants.

The study will also investigate how quickly the body absorbs and gets rid of LY3374849 and how it affects the levels of blood sugar in comparison to insulin degludec, after a single dose is given by injection under the skin and directly into a vein.

Participation in this study includes screening, which is required within 28 days before start of study and a follow up at least 28 days after receiving the last dose of study drug.

This study has 3 parts:

• Participants in Part A will complete 1 study period (approximately 1 week).
• Participants in Part B will complete 3 study periods (approximately 3 weeks).
• Participants in Part C will complete 2 study periods (approximately 2 weeks).

Parts B and C added per protocol amendment, approved in April 2019.

Inclusion Criteria:

• Healthy male or a female who cannot become pregnant
• Have a body mass index (BMI) of at least 18 kilogram per square meter (kg/m²)
• Have normal blood pressure, pulse rate, electrocardiogram (ECG), blood and urine laboratory test results that are acceptable for the study
• Have veins suitable for easy blood collection and glucose solution infusion

Exclusion Criteria:

• Are currently participating in or completed a clinical trial within the last 30 days or any other type of medical research judged to be incompatible with this study
• Had donated or had blood loss of more than 450 milliliters (mL) within the last 3 months
• Have a regular alcohol intake greater than 21 units/week (male), or 14 units/week (female)
• Smoke more than 10 cigarettes per day
• Are infected with hepatitis B or human immunodeficiency virus (HIV)
• Have a history of allergies or reactions to more than one drug, or significant severe drug allergy
• Are taking illegal drugs

Double-blind in Part A. Open label in Parts B and C.