What is the best approach to initiate basal insulin therapy for a patient with hyperglycemia?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: December 16, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

How to Explain Basal Insulin to Your Patient

Basal insulin is a once-daily, long-acting insulin that works continuously throughout the day and night to control your blood sugar between meals and overnight by mimicking the small, steady amount of insulin your pancreas would normally release. 1

What Basal Insulin Does

  • Basal insulin controls your "background" blood sugar by restraining your liver from releasing too much glucose, particularly overnight and between meals 1
  • It provides approximately 24 hours of steady insulin coverage without causing peaks or sudden drops in insulin levels 2, 3
  • This is different from mealtime insulin, which handles the sugar spikes that occur after eating 4, 2

Starting Your Basal Insulin

You will typically start with 10 units once daily or 0.1-0.2 units per kilogram of your body weight, depending on how high your blood sugar is 5, 6

  • The dose is injected under the skin (subcutaneously) into your abdomen, thigh, or upper arm 6
  • You must take it at the same time every day (though the specific time can be any time that works for your schedule) 1, 6
  • You should continue taking your metformin and possibly other diabetes pills alongside basal insulin 5

How We'll Adjust Your Dose

Your dose will be increased by 2-4 units every 3-7 days until your fasting blood sugar reaches 80-130 mg/dL 5, 7

  • You'll need to check your fasting blood sugar (first thing in the morning before eating) to guide these adjustments 1, 5
  • If you experience low blood sugar (hypoglycemia), we'll reduce your dose by 10-20% 1
  • Patient self-titration using a written algorithm improves blood sugar control, so you may be given instructions to adjust your own dose based on your readings 5

Important Safety Information

Rotate your injection sites within the same body region (for example, different spots on your abdomen) to prevent lumps or skin changes that can affect insulin absorption 6, 8

  • Never inject into areas with lumps or skin changes 6
  • Do not mix basal insulin with any other insulin or dilute it 6
  • Learn to recognize and treat low blood sugar: symptoms include shakiness, sweating, confusion, and rapid heartbeat 1, 5
  • Always keep fast-acting sugar (glucose tablets, juice) available 5

When Basal Insulin Alone Isn't Enough

If your A1C remains above goal after optimizing basal insulin, or if your blood sugar spikes significantly after meals (above 180 mg/dL), you'll need to add mealtime insulin or a GLP-1 medication 1, 7

  • Signs you need additional medication include: high bedtime-to-morning blood sugar differences (≥50 mg/dL), continued high A1C despite reasonable basal doses, or frequent low blood sugars 1
  • We prefer adding a GLP-1 medication before adding mealtime insulin because it causes less weight gain and fewer low blood sugar episodes 1

Common Misconceptions to Avoid

Starting insulin does not mean you've failed – type 2 diabetes is a progressive disease where the pancreas makes less insulin over time, and insulin therapy is often necessary and beneficial 1

  • Insulin is not a punishment; it's a powerful tool to prevent complications 1
  • Delaying insulin when needed prolongs exposure to high blood sugar and increases your risk of complications 7
  • Basal insulin alone will not control blood sugar spikes after meals – that requires additional medication 1, 4

What You Need to Monitor

  • Check your fasting blood sugar daily (before breakfast) 5
  • Keep a log of your readings to identify patterns 5
  • Report any episodes of blood sugar below 70 mg/dL immediately 5
  • Increase monitoring frequency during dose adjustments or if you're sick 6

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Insulin glargine: a new basal insulin.

The Annals of pharmacotherapy, 2002

Guideline

Initial Insulin Therapy Dosing and Regimen

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Insulin Intensification for Patients with Elevated A1c

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Research

EADSG Guidelines: Insulin Therapy in Diabetes.

Diabetes therapy : research, treatment and education of diabetes and related disorders, 2018

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.