What to Know About Toujeo (Insulin Glargine Injection)

A Long-Acting Insulin Drug Approved to Treat Type 1 and 2 Diabetes

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Toujeo (insulin glargine injection) is a brand-name-only form of prescription insulin approved to help reduce blood sugar in adults with type 1 or type 2 diabetes. Toujeo contains a concentrated form of long-acting synthetic insulin called insulin glargine, which is used to partially replace the body's natural production of insulin, helping to remove excess glucose (sugar) from the bloodstream. The delivery method for Toujeo is a pre-filled pen, which is used once daily via subcutaneous (under the skin) injections. Common brands include Lantus Solostar, Toujeo SoloStar, and Basaglar KwikPen.

Injection with insulin pen stock photo
Milos Dimic / Getty Images


Toujeo is approved by the Food and Drug Administration for adults and children over 6 with diabetes who require long-acting supplemental insulin in order to control their blood glucose.

Insulin is the hormone produced by the pancreas that is responsible for taking glucose (sugar) from the blood to the cells to use for energy. You may need insulin if you are insulin-resistant, unable to control your blood sugars with oral diabetes medicine or other medication combinations, or if you have had diabetes for an extended period of time. Over time, beta cells that form insulin can die off or become sluggish, and injectable insulin such as Toujeo may be required to help get blood sugars to the target level determined by your healthcare provider.

Toujeo works to supplement your body's current insulin production. As a long-acting insulin, it should be effective for an entire day—even up to 36 hours. In some cases, other forms of insulin (short-acting, typically taken with meals) and non-insulin diabetes medications (such as metformin) also may be prescribed to help you reduce your blood glucose levels to a controlled level.

Toujeo for Type 1 Diabetes

In a pivotal trial used to support the use of Toujeo for type 1 diabetes, the drug was compared with Lantus. The study found that Toujeo provided similar glucose control with a lower risk of hypoglycemia, independently of time of injection, and less weight gain.

Toujeo for Type 2 Diabetes

Similarly, pivotal trials supporting the use of Toujeo in type 2 diabetes compared with Lantus have shown that Toujeo controls blood glucose as well as Lantus for people with type 2 diabetes treated with basal and mealtime insulin, but with consistently less risk of nocturnal hypoglycemia.

Before Taking

People with diabetes often start with a small amount of long-acting basal insulin to help get their blood sugar to the target level. Basal insulin is meant to act as a baseline or background insulin—its goal is to release a small amount of insulin over a 24-hour period. It is not used to lower mealtime sugar, but rather to help reduce your blood sugar throughout the day.

Toujeo is three times more concentrated (300 units/ml) than Lantus. The concentrated formula of Toujeo means the release of insulin is slower and therefore may reduce the risk of hypoglycemia (low blood sugar).

Even though they both are forms of insulin glargine, Toujeo and Lantus should not be used interchangeably, as they vary in concentration.

Toujeo may be a good alternative for patients with hypoglycemia or insulin resistance requiring larger doses of insulin.

Precautions and Contraindications

Toujeo is not recommended for the treatment of diabetic ketoacidosis and should not be used during episodes of hypoglycemia.

Do not use Toujeo if you are allergic to insulin or insulin products. Seek immediate medical care if you use Toujeo and develop any of the following symptoms of an allergic reaction:

  • A rash over your entire body
  • Trouble breathing
  • Shortness of breath
  • Fast heartbeat
  • Sweating
  • Swelling of your face, tongue, or throat
  • Extreme drowsiness, dizziness, or confusion

Toujeo should not be given to children under 6. Talk to your healthcare provider before using Toujeo if you have liver or kidney problems, if you are pregnant or considering becoming pregnant, breastfeeding, or considering breastfeeding.

Other long-acting basal insulin drugs similar to Toujeo include:

  • Lantus, Basaglar (glargine)
  • Tresiba (degludec)
  • Levemir (detemir)
  • Neutral protamine Hagedorn (NPH)


According to the manufacturer, Sanofi-Aventis, the dosage of Toujeo should be individually determined by your prescribing healthcare provider depending on your type of diabetes, personal metabolic needs, and blood glucose control.

Toujeo is formulated as 300 units per milliliter (mL) insulin glargine in two options:

  • 1.5 mL Toujeo SoloStar disposable prefilled pen (450 units of insulin per pen; 3 pens per pack). It delivers doses in one-unit increments and can deliver up to 80 units per injection.
  • 3 mL Toujeo Max SoloStar disposable prefilled pen (900 units of insulin per pen; 2 pens per pack). It delivers doses in two-unit increments and can deliver up to 160 units per injection. This form is recommended for people requiring at least 20 units per day.


Dosage for type 1 diabetes: As a general rule of thumb, the manufacturer-recommended dosage for people with type 1 diabetes who are new to insulin should be calculated as follows: 0.2 to 0.4 units of insulin per kilogram (kg) of body weight. In patients who are new to insulin, the initial dose should be divided and administered at different points throughout the day, as determined by your prescribing healthcare provider.

Since Toujeo is highly concentrated, injection volume will be less when compared to other forms of insulin, such as the Lantus pen. Depending on your dose of insulin, you may have to change pens less often because the pen holds more insulin.

Dosage for type 2 diabetes: For those with type 2 diabetes who are new to insulin, the manufacturer recommends a dosage of 0.2 units per kg of body weight once daily. If you also take other glucose-lowering drugs in addition to Toujeo, the dosage of those drugs may need to be adjusted accordingly by your healthcare provider.

Dosage for people over 65: The manufacturer recommends a more conservative dosage than 0.2 units per kg of body weight, due to the increased risk of hypoglycemia with advanced age.

When first starting on insulin or switching to a new form of insulin, be sure to regularly monitor your blood glucose levels using a glucometer. If you're already taking insulin in another form and transitioning to Toujeo, your healthcare provider can help you titrate your dosage accordingly.

How to Take and Store

The dose should be administered once daily at the same time each day (typically morning or night) via a subcutaneous (under the skin) injection in one of three locations:

  • Under the skin in the abdomen (at least 2 inches away from your belly button)
  • In your thigh
  • In your deltoid (upper arm near the shoulder)

Note that Toujeo doesn't start to work immediately—it may take up to 5 days to be fully effective.

Do not use Toujeo in an insulin pump or as an injection into your vein (intravenously). It's best to rotate your injection site to reduce the risk of lipohypertrophy, a condition where a small, benign lump or dent may form in skin and fat tissue at a repeated injection site. Never dilute or mix insulin with any other solution.

Toujeo doesn't need to be administered with food, though people with type 1 and type 2 diabetes who are taking insulin should generally follow consistent diet and exercise schedules. Work with your healthcare team to find a plan that works for you.

Note that needles for the Toujeo pen are sold separately, and a new needle must be attached before each injection to reduce the risk of needle blockages and subsequent underdosage or overdosage.

Missing a dose: If you take too little insulin or miss a dose, high blood sugar (hyperglycemia) may result, as there won't be sufficient insulin to effectively remove glucose from your bloodstream. Symptoms of hyperglycemia include:

  • Excessive thirst (polydipsia)
  • Increased hunger (polyphagia)
  • The need to urinate more frequently than usual (polyuria)
  • Blurred vision
  • Feeling tired and weak

Exceeding the dosage: If you take more than the recommended dose, low blood sugar (hypoglycemia) may result, as too much glucose could be removed from your bloodstream. Symptoms of hypoglycemia include:

  • Trembling or weakness
  • Fast heartbeat
  • Sweating
  • Headache
  • Fatigue or feeling sleepy
  • Pale skin
  • Anxiety or irritability
  • Talking or yelling when you're sleeping
  • A tingling feeling around your mouth
  • Hunger
  • Dizziness
  • Confusion
  • Double or blurred vision
  • Lack of coordination
  • Seeming as if you're intoxicated
  • Convulsions or unconsciousness

Overdosage: There is no listed specific overdosage amount, as the adequate dosage will vary from person to person. If you take too much insulin, mild hypoglycemia can be treated with oral glucose. Severe hypoglycemia requires immediate medical attention, because it may lead to neurological damage, seizure, or coma. Overdose may also result in low potassium levels (hypokalemia), which should be treated by a medical professional.

Storage: Unopened Toujeo pens should be stored in the refrigerator, but never the freezer. Discard the pen if it has been frozen. Opened Toujeo pens that are in-use should be kept at room temperature (below 86ºF and out of direct heat and light), with the cap on when not being used.

Anyone on insulin should always keep a glucagon emergency kit nearby. They should also educate their loved ones and friends on how to use it if they are found passed out, or when it is unsafe for them to eat or drink something with glucose in it to raise their blood glucose level.

Side Effects

There are several side effects that may occur as a result of taking Toujeo, both mild and severe.


The most common side effect of taking Toujeo or any insulin is low blood sugar. Other potential common side effects include:

  • Weight gain
  • Itching
  • Rash
  • Swelling
  • Allergic reactions, including reactions at the injection site, skin thickening, or pits at the injection site (lipodystrophy)
  • Low blood potassium (hypokalemia)


Potentially severe side effects include the following.

  • Severe hypoglycemia: A condition marked by very low blood sugar requiring immediate medical attention
  • Severe allergic reaction: A whole-body reaction including a rash, shallow breathing, heart palpitations, and sweating
  • Heart failure: Taking another diabetes medication such as Actos or Avandia (thiazolidinediones, or TZDs) in conjunction with Toujeo may result in heart failure, regardless of whether you've ever had heart problems before. Symptoms to watch out for include shortness of breath, swelling of your ankles or feet, and sudden weight gain.

Warnings and Interactions

It's important that you continue to regularly keep track of your glucose levels while using Toujeo. Be aware that your Toujeo dosage may need to shift if you increase your exercise levels, lose or gain weight, change your diet, have increased amounts of stress, or become sick.

According to the manufacturer, it is not recommended to operate heavy machinery while first taking Toujeo until you know how the drug affects you. Do not drink alcohol or use over-the-counter medications that contain alcohol while using Toujeo, since these could exacerbate hypoglycemia.

There is a very serious known interaction between Toujeo and TZDs, such as Actos and Avandia, which could result in heart failure. If you're taking TZDs currently for diabetes, consult with your healthcare provider about close monitoring while using Toujeo.

Toujeo also offers a coaching service available for anyone with a prescription for the drug. The Toujeo Coach service is a great way to help you stay on track of your glucose and insulin levels. Together with your Toujeo coach, you can develop a dosing schedule, as well as input your numbers, get reminders, and help you stay on top of any changes your healthcare provider makes to your routine.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Home PD, Bergenstal RM, Bolli GB, Ziemen M, et al. New Insulin Glargine 300 Units/mL Versus Glargine 100 Units/mL in People With Type 1 Diabetes: A Randomized, Phase 3a, Open-Label Clinical Trial (EDITION 4). Diabetes Care. 2015 Dec;38(12):2217-25. doi: 10.2337/dc15-0249.

  2. Riddle MC, Bolli GB, Ziemen et al; EDITION 1 Study Investigators. New insulin glargine 300 units/mL versus glargine 100 units/mL in people with type 2 diabetes using basal and mealtime insulin: glucose control and hypoglycemia in a 6-month randomized controlled trial (EDITION 1). Diabetes Care. 2014 Oct;37(10):2755-62. doi: 10.2337/dc14-0991.

By Barbie Cervoni MS, RD, CDCES, CDN
Barbie Cervoni MS, RD, CDCES, CDN, is a registered dietitian and certified diabetes care and education specialist.