Toujeo (Insulin Glargine U-300): How This Concentrated Long-Acting Insulin Works and When Telehealth Is Enough

Last updated: August 18, 2026

Toujeo is a brand name for insulin glargine U-300, a concentrated long-acting (basal) insulin analog. Clinicians use it to improve blood sugar control in adults and in children 6 years and older with diabetes mellitus. People also search “Toujeo insulin,” “Toujeo SoloStar,” “Toujeo Max SoloStar,” and “insulin glargine 300.” Those names point to this U-300 product, not to Lantus, Basaglar, Semglee, or other U-100 insulin glargine pens. Toujeo is not a meal-time insulin, not an insulin pump cartridge, and not a treatment for diabetic ketoacidosis.

This guide covers how Toujeo is usually injected, how SoloStar and Max SoloStar pens differ, what the FDA label says about starting doses and switches from Lantus or twice-daily NPH, and when a video visit is enough versus when you need labs or the ER. It is educational. It is not a diagnosis or a promise that any specific insulin will be prescribed. Do not change brands or units on your own.

Want a licensed clinician to review basal insulin or an A1C? Klarity Health has 2,000+ licensed providers. Many visits happen online. See online prescription options or browse conditions.

TLDR

• Toujeo is insulin glargine 300 units/mL for type 1 and type 2 diabetes in people 6 years and older. In type 1 diabetes it must be paired with a short-acting insulin. It is not given in a vein or an insulin pump (MedlinePlus insulin glargine; DailyMed Toujeo U-300 label).
• Mayo Clinic describes insulin glargine as a long-acting insulin that works slowly over about 24 hours. Inject it under the skin of the abdomen, upper arm, or thigh. Rotate sites. Do not inject into a vein or muscle (Mayo Clinic insulin glargine).
• FDA/DailyMed: inject once daily at any time of day, at the same time every day. Do not dilute or mix. Never transfer Toujeo from the pen cartridge into a syringe. Titrate no more often than every 3 to 4 days. The full glucose-lowering effect of a dose may take five days. Onset after an injection develops over about 6 hours.
• Insulin-naive type 2 start: 0.2 units/kg once daily. Insulin-naive type 1: about one-third to one-half of total daily insulin as Toujeo; remaining meal-time insulin covers meals. A common first total daily insulin estimate is 0.2 to 0.4 units/kg.
• Switch from once-daily long- or intermediate-acting insulin: start Toujeo at the same unit dose. People controlled on Lantus (U-100) often need a higher daily Toujeo dose later to keep the same control. Switch from twice-daily NPH or detemir: start at 80% of the total daily dose. Monitor glucose often in the first weeks.
• SoloStar: 1.5 mL, 450 units, 1-unit clicks, up to 80 units per injection. Max SoloStar: 3 mL, 900 units, 2-unit clicks, up to 160 units; recommended if you need at least 20 units per day. The dose counter shows units of Toujeo. No extra math for U-300 versus U-100 if you stay on the branded pen.
• Typical home glucose targets many adults use: 80 to 130 mg/dL before meals and under 180 mg/dL two hours after a meal starts. A reading under 70 mg/dL is low (CDC manage blood sugar).
• Medicare covers many telehealth visits from home anywhere in the U.S. through December 31, 2027 (HHS telehealth policy). Seizure, loss of consciousness, chest pain, or blood sugar that will not come up is 911, not a video visit.

What Toujeo is trying to fix

Type 1 diabetes means the pancreas makes little or no insulin. Type 2 diabetes means the body resists insulin and often does not make enough of it. Glucose stays in the blood. Over years that raises the chance of heart disease, stroke, kidney disease, nerve damage, and eye disease. NIDDK notes some people with type 2 diabetes can control glucose with food, activity, sleep, and weight change. Many still need pills or insulin. Over time you may need more than one medicine (NIDDK insulin and medicines).

Insulin glargine replaces background insulin. MedlinePlus says it moves sugar from the blood into tissues and slows the liver from making more sugar. It does not cover the spike right after a meal. That is why type 1 regimens add a short-acting insulin at meals, and why some type 2 regimens still use meal-time insulin or an oral class.

Typical home targets the CDC lists for many adults:

• Before a meal: 80 to 130 mg/dL
• Two hours after the start of a meal: under 180 mg/dL

Blood sugar under 70 mg/dL is low. If you are sick and a reading is 240 mg/dL or higher, check ketones. High ketones can signal diabetic ketoacidosis, which is an emergency. Toujeo is not the insulin used to treat DKA. The DailyMed label says Toujeo is not recommended for diabetic ketoacidosis.

Related Klarity guides: Lantus (insulin glargine U-100), Tresiba (insulin degludec), Levemir (insulin detemir), type 2 diabetes medication, SGLT2 inhibitors, sulfonylureas, DPP-4 inhibitors, and TZDs.

How Toujeo is usually taken

Toujeo is a clear, colorless U-300 solution in a prefilled pen. DailyMed adult directions:

• Once a day, at the same time every day. Any clock time is allowed if it stays consistent.
• Sites: abdomen, thigh, or deltoid (upper arm). Rotate within the same region. Do not inject into lipodystrophy or cutaneous amyloidosis.
• Do not inject into a vein or muscle. Do not use in an insulin pump. Do not dilute or mix with any other insulin or solution.
• Never transfer Toujeo from the SoloStar or Max SoloStar cartridge into a syringe. A U-100 syringe would deliver the wrong dose.
• People with visual impairment who rely on audible clicks should use extra caution when they dial a dose.

Two pens:

• Toujeo SoloStar: 1.5 mL, 450 units, 1-unit increments, maximum 80 units in one injection.
• Toujeo Max SoloStar: 3 mL, 900 units, 2-unit increments, maximum 160 units in one injection. The label recommends this pen if you need at least 20 units per day.

If you switch between SoloStar and Max SoloStar and your last dose was an odd number, the clinician usually raises or lowers the dose by 1 unit so it matches the 2-unit Max clicks. The pen’s dose counter already shows units of Toujeo. You do not convert U-300 milliliters in your head if you use the branded pen as labeled.

Starting doses on the DailyMed label (insulin-naive):

• Type 2: 0.2 units per kilogram once daily.
• Type 1: about one-third to one-half of the planned total daily insulin as Toujeo; the rest is short-acting insulin at meals. A general first total daily insulin estimate is 0.2 to 0.4 units/kg.

The maximum glucose-lowering effect of a Toujeo dose may take five days. The first dose may not cover the first 24 hours. Onset develops over about 6 hours. If someone is coming off IV insulin, that delay matters. Titrate no more often than every 3 to 4 days. Check glucose daily when you start.

Switching from another insulin (DailyMed):

• From once-daily long- or intermediate-acting insulin: start Toujeo at the same unit dose.
• From Lantus U-100 when already controlled: expect that a higher daily Toujeo dose will later be needed for the same control. On a unit-to-unit basis, Toujeo has a lower glucose-lowering effect than Lantus.
• From twice-daily NPH or insulin detemir: start Toujeo at 80% of the total daily dose.
• Check glucose often in the first weeks. Do not treat pen clicks on a Lantus SoloStar as the same as a Toujeo SoloStar.

MedlinePlus storage for insulin glargine products: keep unopened pens in the refrigerator and never freeze. Opened pens stay at room temperature and are typically discarded after 28 days. Confirm the Toujeo carton insert for the exact in-use window on your pen. Never share a pen or needle, even if you change the needle.

Who should not use Toujeo

DailyMed contraindications: do not use during a low-blood-sugar episode, and do not use if you are allergic to insulin glargine or any Toujeo excipient.

Other label cautions:

• Never share a SoloStar or Max SoloStar pen between patients.
• Combining insulin with a TZD (pioglitazone, rosiglitazone) can cause fluid retention and heart failure. Watch for sudden weight gain, ankle swelling, or shortness of breath.
• Hypokalemia can be serious. Clinicians may check potassium in people at risk.
• Kidney or liver impairment can raise hypoglycemia risk.
• Beta-blockers, clonidine, guanethidine, and reserpine can hide some low-sugar warning signs.

MedlinePlus also flags pregnancy, breastfeeding, planned surgery, alcohol, and illness as reasons to talk with the prescriber before you change anything.

Side effects people actually feel

The most common problem is low blood sugar. DailyMed notes severe hypoglycemia in about 6.6% of adults with type 1 diabetes on Toujeo plus meal-time insulin at 26 weeks, and glucose under 54 mg/dL in 77.7%. In type 2 trials, severe hypoglycemia was about 5% when Toujeo was part of a multiple daily injection plan, and about 1% when it was basal insulin only.

Other reactions listed at 5% or more in trials include nasopharyngitis and upper respiratory infection. The highlights also list allergic reactions, injection-site reaction, lipodystrophy, itching, rash, edema, and weight gain. Postmarketing reports include localized cutaneous amyloidosis at the injection site. Repeated shots in those spots can raise glucose; a sudden move to unused skin can drop it.

Serious allergy (rash all over, wheezing, swelling of the face or throat) is an emergency. Call 911.

When telehealth is enough, and when it is not

A video visit can often cover: reviewing home glucose or CGM logs, explaining the difference between Toujeo and Lantus, walking through SoloStar versus Max SoloStar, planning a labeled start or switch, checking whether an oral medicine still belongs in the mix, and deciding if labs (A1C, kidney, potassium) are due. Klarity Health has 2,000+ licensed providers. Many diabetes follow-ups happen online. See online prescription options.

Medicare patients can receive many non-behavioral telehealth visits from home anywhere in the United States through December 31, 2027. Coverage for a specific visit still varies by plan. Verify benefits before you book.

Go to urgent or emergency care, not a routine video slot, if you have:

• Seizure, loss of consciousness, or confusion that does not clear with sugar
• Blood sugar that stays low after treatment, or stays at 240 mg/dL or higher with ketones when you are sick
• Chest pain, severe shortness of breath, or signs of a severe allergic reaction
• Repeated vomiting and you cannot keep fluids down

Insurance, cost, and what “may be covered” means

Whether a plan covers Toujeo, prefers Lantus or a biosimilar U-100 glargine, or requires prior authorization varies by formulary and year. Toujeo is not interchangeable with Lantus at the counter just because both contain insulin glargine. A clinician and pharmacist still have to match the product, the pen, and the units.

This article does not promise coverage. Check your plan and confirm the exact NDC with the pharmacy before you count on a fill.

FAQ

Is Toujeo the same as Lantus?

Both are insulin glargine, but Toujeo is U-300 and Lantus is U-100. DailyMed says Toujeo has a lower glucose-lowering effect unit-for-unit than Lantus, a slower onset (about 6 hours), and a full effect that may take five days. People who switch from controlled Lantus often need more daily units of Toujeo later. Do not swap pens without a clinician.

Can I use Toujeo in a pump or a syringe?

No. The label says do not use Toujeo in an insulin pump, do not give it IV, and never transfer it from the pen into a syringe.

What if I miss a dose?

MedlinePlus tells you to get written instructions from your own clinician before the first fill. Because Toujeo lasts a long time and takes days to reach full effect, do not double a dose from memory. Check glucose and call the prescriber or the after-hours line.

Can I take Toujeo with metformin or a GLP-1?

Many type 2 regimens combine basal insulin with metformin or other oral or injectable classes. DailyMed lists GLP-1 receptor agonists, DPP-4 inhibitors, and SGLT2 inhibitors among drugs that can raise hypoglycemia risk when used with Toujeo. Dose changes belong to the clinician who sees your logs.

Bottom line

Toujeo is concentrated insulin glargine for once-daily basal coverage in people 6 and older. The pen, the units, and the five-day ramp are different from Lantus. A licensed clinician can decide if this product fits, how to start or switch, and which labs to order. Klarity Health can often do that review by video. See online prescription options or browse conditions.

Educational only. Not medical advice. Insulin products and coverage vary. Verify your prescription and benefits before you change therapy. Klarity Health has 2,000+ licensed providers.