Comprehensive medication guide to Insulin Glargine including estimated pricing, availability information, side effects, and how to find it in stock at your local pharmacy.
Estimated Insurance Pricing
$0–$35 copay for most commercially insured patients; Medicare Part D patients capped at $35/month under the Inflation Reduction Act; Tier 1–3 depending on plan and preferred product; prior authorization increasingly required post-Semglee discontinuation.
Estimated Cash Pricing
$80–$360 retail for brand Lantus; as low as $35/month with the Sanofi Valyou Savings Program for all patients; generic insulin glargine with GoodRx as low as $54–$75 per vial for a 30-day supply.
Medfinder Findability Score
45/100
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Insulin Glargine is a long-acting basal insulin analog used to control blood sugar in people with Type 1 and Type 2 diabetes. Sold under brand names including Lantus, Toujeo, Basaglar, and Rezvoglar, it is injected once daily subcutaneously and provides a steady, peakless level of insulin coverage for approximately 24 hours — closely mimicking the natural basal insulin secretion of a healthy pancreas.
Insulin Glargine is FDA-approved for adults with Type 1 and Type 2 diabetes, and for children ages 6 and older with Type 1 diabetes. It is one of the most prescribed insulins in the United States, with an estimated 38 million Americans living with diabetes who may rely on insulin therapy.
Multiple products are available in 2026 at 100 units/mL (U-100): Lantus, Basaglar KwikPen, Rezvoglar, Langlara, and generic insulin glargine. Toujeo is available at 300 units/mL (U-300). Semglee (insulin glargine-yfgn) was discontinued on December 31, 2025.
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Insulin Glargine is a recombinant human insulin analog with two modifications: asparagine at position 21 of the A chain is replaced with glycine, and two arginine residues are added to the B chain. These changes make the molecule soluble only in acidic conditions (pH 4.0).
When injected into the slightly alkaline subcutaneous tissue, the acidic solution is neutralized, causing the insulin molecules to form microprecipitates — tiny crystals that slowly dissolve over approximately 24 hours. This creates a relatively constant, peakless release of insulin into the bloodstream, mimicking natural basal insulin secretion.
Like natural insulin, Insulin Glargine binds to insulin receptors on muscle, fat, and liver cells, facilitating glucose uptake and suppressing hepatic glucose production — keeping blood sugar stable between meals and overnight.
100 units/mL (U-100) — 10 mL vial
Lantus brand; also available as generic; use with U-100 syringe
100 units/mL (U-100) — 3 mL SoloStar prefilled pen
Lantus SoloStar; delivers 1–80 units per injection in 1-unit increments
100 units/mL (U-100) — 3 mL KwikPen
Basaglar brand by Eli Lilly; 1-unit increments from 1–80 units
300 units/mL (U-300) — 1.5 mL SoloStar prefilled pen
Toujeo brand; NOT interchangeable 1:1 with U-100 products
300 units/mL (U-300) — 3 mL Max SoloStar prefilled pen
Toujeo Max; for patients requiring ≥20 units/day; 2-unit increments
In 2026, the Insulin Glargine market is experiencing intermittent availability disruptions. Brand Lantus is not in a formal FDA shortage, but the December 31, 2025 discontinuation of Semglee (the most widely used interchangeable biosimilar) has created a demand surge for remaining products. Pen formulations are harder to find than vials at many pharmacies, and some regions experience more consistent stockouts than others.
Insurance formulary transitions add further complexity — many plans are updating their preferred drug lists in real-time, leading to new prior authorization requirements for some patients switching from Semglee to Lantus or Basaglar.
The most efficient way to find Insulin Glargine in stock near you is to use medfinder, which calls pharmacies in your area to find which ones can fill your specific prescription — saving you time and frustration.
Insulin Glargine is not a controlled substance, so any licensed prescriber in the United States can write a prescription for it — no DEA registration beyond standard prescribing authority is required. It can be prescribed by a wide range of healthcare professionals who manage diabetes.
Telehealth providers can prescribe Insulin Glargine for established Type 2 diabetes patients through platforms like Teladoc, MDLive, and Doctor On Demand. New-onset Type 1 diabetes typically requires in-person evaluation by an endocrinologist due to clinical complexity.
No. Insulin Glargine is not a controlled substance and has no DEA scheduling. Any licensed prescriber in the United States can write a prescription for Insulin Glargine without special DEA registration or restrictions. There are no federal limitations on refill quantities or prescription validity windows from a controlled substance perspective.
However, insurance plans may impose their own quantity limits, prior authorization requirements, and step therapy requirements that govern access. These are insurance-level restrictions, not federal controlled substance regulations. Patients can generally receive 30-day or 90-day supplies without the restrictions that apply to Schedule II–V controlled substances.
Common side effects (usually manageable):
Serious side effects requiring medical attention:
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Insulin Detemir (Levemir)
Long-acting insulin analog by Novo Nordisk; similar mechanism to glargine but slightly shorter duration; often requires twice-daily dosing; 1:1 starting dose when switching from glargine
Insulin Degludec (Tresiba)
Ultra-long-acting insulin analog by Novo Nordisk; duration up to 42 hours; very flat action profile; lower day-to-day variability than glargine; has experienced its own intermittent shortages
NPH Insulin (Humulin N, Novolin N)
Older intermediate-acting insulin; peaks 4–12 hours post-injection; requires twice-daily dosing; available over-the-counter at Walmart (ReliOn brand) — emergency use only under physician guidance
Toujeo (insulin glargine U-300)
Same active ingredient but 3x more concentrated; longer, flatter action profile; lower nocturnal hypoglycemia risk; not a 1:1 dose conversion when switching from U-100 products
Prefer Insulin Glargine? We can find it.
Beta-blockers (metoprolol, atenolol, propranolol)
moderateMask tachycardia symptoms of hypoglycemia; increase frequency of blood glucose monitoring if on beta-blockers
Corticosteroids (prednisone, methylprednisolone)
majorCause significant blood sugar elevation and insulin resistance; may require substantially higher insulin doses during steroid courses
ACE inhibitors (lisinopril, captopril, enalapril)
moderateEnhance glucose-lowering effect; monitor blood sugar when starting or adjusting ACE inhibitor doses
ARBs (candesartan, valsartan, losartan)
moderateMay require insulin dose adjustment; increased glucose monitoring recommended with concomitant use
Antipsychotics (olanzapine, quetiapine, clozapine)
moderateCan cause significant insulin resistance and blood sugar elevation; monitor glucose closely when starting antipsychotic therapy
Thiazolidinediones (pioglitazone, rosiglitazone)
majorFluid retention and heart failure risk when combined with insulin; monitor for weight gain and edema
Alcohol
moderateCan cause prolonged severe hypoglycemia; blocks liver glucose release when blood sugar drops; avoid drinking on an empty stomach
Clonidine
moderateMasks hypoglycemia symptoms and may reduce blood sugar; monitor carefully
Insulin Glargine remains the cornerstone of basal insulin therapy for millions of Americans with diabetes. Despite the disruption caused by Semglee's December 2025 discontinuation and the Basaglar Tempo pen phase-out, multiple products are still available in 2026. The key is knowing which ones are in stock at pharmacies near you, and how to pay no more than $35/month with available savings programs.
Pricing improvements since 2023 — including Sanofi's 78% list price reduction and the expanded Valyou Savings Program — mean Insulin Glargine is more affordable than at any point in the past decade. The $35/month Medicare cap under the Inflation Reduction Act provides additional relief for Medicare patients.
If you're having trouble locating Insulin Glargine at your pharmacy, medfinder calls pharmacies near you to find which ones have your specific product in stock — so you can get the medication you need without the runaround.
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Our medication guides are researched and written to help patients make informed decisions. All content is reviewed for accuracy and updated regularly. Learn more about our standards
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