Toujeo Max SoloStar is a prefilled insulin pen that holds 900 units of concentrated insulin glargine, designed for people with diabetes who need higher daily doses. It delivers up to 160 units in a single injection, making it the larger of two Toujeo pen options. The “Max” distinction matters because the two pens differ in total capacity, dose increments, and maximum injection size.
How Toujeo Max Differs From Standard Toujeo
Both Toujeo pens contain the same insulin at the same concentration: 300 units per milliliter of insulin glargine. That concentration is three times stronger than standard insulin glargine (sold as Lantus), which means a smaller volume of liquid delivers the same number of units. The difference between the two pens is purely mechanical.
The standard Toujeo SoloStar holds 450 units total, dials in 1-unit increments, and caps out at 80 units per injection. Toujeo Max SoloStar holds 900 units total (in 3 mL of liquid), dials in 2-unit increments, and allows up to 160 units per injection. If your prescribed dose falls between even numbers, the Max pen won’t work for you because it can’t dial odd-numbered doses like 37 or 53 units.
The Max pen is typically prescribed for people who need more than 20 units of basal insulin per day. At higher doses, the larger pen simply lasts longer and requires fewer pen changes per month.
What the Pen Does in Your Body
Toujeo is a long-acting basal insulin. You inject it once daily, and it provides a slow, steady release of insulin over roughly 24 hours or longer. The high concentration (300 units/mL) creates a smaller depot under your skin compared to standard-strength insulin glargine. That compact depot dissolves more gradually, which produces a flatter, more even activity profile throughout the day. In practical terms, this means less of a spike-and-fade pattern and a lower risk of blood sugar dropping overnight.
Because Toujeo releases insulin so steadily, it has no pronounced peak. This makes it useful as background insulin that keeps blood sugar from rising between meals and overnight, but it won’t cover the spikes that come from eating. Most people on Toujeo also use a rapid-acting insulin at mealtimes or take oral diabetes medications alongside it.
How to Use the Max Pen
You inject Toujeo Max once a day at the same time each day. The pen uses standard insulin pen needles that screw onto the tip before each injection. Common injection sites include the abdomen, thigh, and upper arm. Rotating your injection spot within the same general area helps prevent the skin from developing hard lumps or fatty deposits that can interfere with insulin absorption.
To set your dose, you turn the dial at the end of the pen. Each click moves the dose by 2 units, up to the 160-unit maximum. A dose window on the pen shows the number you’ve selected. After inserting the needle under your skin, you press the injection button and hold it for several seconds to make sure the full dose is delivered. Always attach a new needle before each injection and remove it afterward to prevent air from entering the cartridge.
Storage and Shelf Life
Before you start using a Toujeo Max pen, store it in the refrigerator. Once you’ve given your first injection from a pen, keep it at room temperature (below 86°F or 30°C) and out of direct heat or sunlight. Do not put a pen back in the fridge after you’ve started using it.
An opened pen is good for 28 days. After that, discard it even if insulin remains inside. The same 28-day rule applies to any pen that has been taken out of the refrigerator, whether or not you’ve used it. Unopened pens stored in the fridge remain usable until the expiration date on the packaging.
Side Effects
Low blood sugar (hypoglycemia) is the most common side effect of any insulin, including Toujeo. Symptoms include shakiness, sweating, confusion, dizziness, and a fast heartbeat. The concentrated formulation and gradual release profile of Toujeo may carry a somewhat lower risk of overnight low blood sugar compared to standard-strength insulin glargine, though the risk is never zero.
Injection site reactions like redness, swelling, or itching can occur but are generally mild. Weight gain is also common with insulin therapy in general. Rarely, insulin can cause allergic reactions or a drop in potassium levels, which may produce muscle cramps or an irregular heartbeat.
Who the Max Pen Is For
Toujeo Max is prescribed for adults with type 1 or type 2 diabetes who need basal insulin and whose doses are high enough to benefit from the larger pen. People with type 2 diabetes who have significant insulin resistance often require daily basal doses well above 80 units, making the Max pen’s 160-unit ceiling essential. Without it, they would need to split their dose into two separate injections from a standard pen.
The 2-unit increment is the main limitation. If your dose requires odd-numbered precision, the standard SoloStar with its 1-unit increments is the better fit. Your prescriber will choose based on your total daily dose and how finely that dose needs to be adjusted.