Fasting insulin

Elevated fasting insulin often develops years before blood sugar rises and signals insulin resistance. Monitoring allows early metabolic intervention to prevent diabetes and cardiometabolic disease.

Most adults benefit from checking fasting insulin once a year as part of a cardiometabolic panel. After a sustained lifestyle change such as more activity, dietary shift, or meaningful weight loss, retest at 8 to 12 weeks.

At baseline / for screening: Once every 12 months from age 30 as part of a cardiometabolic check. More frequently, every 3 to 6 months, if you have pre-diabetes, type 2 diabetes, polycystic ovary syndrome, or a family history of any of these.

When monitoring an intervention or change: Retest 8 to 12 weeks after a sustained lifestyle change, such as reducing refined carbs and added sugars, increasing physical activity, meaningful weight loss, or improving sleep quality. The same window applies after starting or adjusting glucose-lowering medication (metformin, GLP-1 receptor agonist, SGLT2 inhibitor). If a result was above target, reconfirm sooner once you've begun addressing the most likely driver.

Note: Acute stress, recent intense exercise, and poor sleep all raise fasting insulin transiently. Standardize sleep (full night before), fasting (10 to 12 hours), and exercise (none in prior 24 hours); under consistent conditions, retest at 8 to 12 week intervals for meaningful trends.