What Is Xultophy 100/3.6?

1. How does Xultophy work?

Insulin degludec is an ultra-long basal insulin that controls fasting glucose over more than a day. Liraglutide, the molecule in Victoza and Saxenda, is a GLP-1 receptor agonist with a half-life of about 13 hours that raises insulin when glucose is high, suppresses glucagon, slows gastric emptying, and reduces appetite around the clock. Together they cover fasting and post-meal glucose from one injection, and the liraglutide offsets the weight gain and part of the hypoglycemia that insulin alone brings.

The fixed ratio means the liraglutide dose follows the insulin dose: 0.36 mg at 10 units, 1.8 mg at 50. That slow climb is why nausea on Xultophy runs well below liraglutide started on its own ladder, and why the label caps the dose at 50 units, the point where liraglutide reaches its full 1.8 mg.

2. What is the Xultophy dose?

Prior basal insulin or GLP-1 agonist is stopped when Xultophy starts. The dose is titrated up or down by 2 units once or twice a week, every 3 to 4 days at most, toward the fasting glucose target a prescriber sets. The label caps the dose at 50 units and warns against exceeding it, because the liraglutide component would pass its approved 1.8 mg maximum; people who need more basal insulin than that are not candidates. If a dose is missed, the label says to resume the once-daily schedule at the next scheduled dose without doubling up; if more than 3 days have elapsed since the last dose, the label says to reinitiate at the recommended starting dose, and the Medication Guide tells patients to call their healthcare provider for instructions.

The pen delivers 10 to 50 units per injection, in one-unit increments, with a dose counter that shows the units of Xultophy dialled, not separate numbers for each drug. It takes a new pen needle each time; the needle is removed and discarded after every injection and the pen stored without one attached, both to keep the fill sterile and to keep the dose accurate, since a needle left on can let air in or solution leak out.

Storage follows the pattern of other insulin pens: unopened, keep it refrigerated at 36°F to 46°F (2°C to 8°C) until the printed expiration date, protected from light in its original carton, never frozen and never used if it has been frozen. Once a pen is in use, it is good for 21 days at either room temperature, 59°F to 86°F (15°C to 30°C), or in the refrigerator, kept away from direct heat and light either way.

3. How much does Xultophy lower blood sugar?

The label pools 3,908 patients across six 26-week Phase 3 trials, the DUAL program. Three of them answer the practical questions.

Read together: against insulin alone, Xultophy lowers HbA1c at least as much with less weight gain and no extra hypoglycemia. Against a GLP-1 agonist alone, it lowers HbA1c more but adds insulin’s weight and hypoglycemia. Against insulin glargine plus mealtime insulin aspart (basal-bolus), it matches the HbA1c result from one injection a day instead of up to four, with less weight gain and fewer confirmed hypoglycemia events, using less total insulin (40 units versus 84).

In DUAL I, nausea was 8.8% on Xultophy against 19.7% on liraglutide alone and 3.6% on degludec, the slow-ramp effect; in DUAL III it stayed low in both arms, 3.1% on Xultophy versus 4.1% on the unchanged GLP-1 agonist. The Soliqua page shows the same pattern for the glargine-lixisenatide pair.

4. What are the side effects and warnings?

The label opens with liraglutide’s boxed warning: thyroid C-cell tumors at clinically relevant exposures in rats and mice, human relevance unknown, and a contraindication for a personal or family history of medullary thyroid carcinoma or MEN 2. That is the main safety difference from Soliqua, whose lixisenatide component carries no such warning. The label also lists two more contraindications: during an episode of hypoglycemia, and hypersensitivity to insulin degludec, liraglutide, or any excipient.

The label carries three limitations of use: it should not be combined with any other liraglutide-containing product or another GLP-1 receptor agonist; it is not recommended for diabetic ketoacidosis; and it has not been studied together with mealtime (prandial) insulin.

The warnings and precautions cover pancreatitis, hypoglycemia, acute kidney injury from dehydration, gastrointestinal reactions, hypersensitivity, gallbladder disease, hypokalemia from insulin, fluid retention and heart failure with thiazolidinediones, pulmonary aspiration under anesthesia, and never sharing pens even with the needle changed. The most common adverse reactions are nasopharyngitis, headache, nausea, diarrhea, upper respiratory infection, and raised lipase. In DUAL I, hypoglycemia ran 1.8 episodes per patient-year, below degludec’s 2.6 and far above liraglutide’s 0.2; the insulin sets that number.

For special populations, the label says Xultophy should be used in pregnancy only if the benefit justifies the risk to the fetus, based on animal data showing risk from liraglutide, with no human data on Xultophy itself. Safety and effectiveness have not been established in pediatric patients. In mild-to-moderate kidney impairment there is limited experience, and dose adjustment with added glucose monitoring may be needed; it has not been studied in severe kidney impairment. It has not been studied at all in hepatic impairment, though its insulin degludec component alone shows no clinically relevant pharmacokinetic difference across mild, moderate, and severe hepatic impairment.

The label’s own pharmacokinetics give the two components’ durations: insulin degludec has a half-life of about 25 hours, and liraglutide’s is about 13 hours, which is why once-daily dosing at any time works for both.

5. How is Xultophy related to Tresiba and Victoza?

Xultophy is built from two drugs Novo Nordisk already sells on their own. Tresiba is insulin degludec alone, dosed in units with no fixed daily ceiling set by a second drug. Victoza is liraglutide alone, titrated in 0.6 mg steps up to a 1.8 mg maximum. Xultophy locks the two into a single pen at a fixed 1-unit-to-0.036-mg ratio, which is also why its dose tops out at 50 units: that is the unit count at which the liraglutide side reaches Victoza’s own 1.8 mg ceiling.

A person already stable on Tresiba or Victoza switches to Xultophy at 16 units rather than starting the titration over, and stops the single-ingredient product first, since the label does not recommend combining Xultophy with another liraglutide-containing product or GLP-1 receptor agonist.

6. How does Xultophy compare with Soliqua?

The choice is the GLP-1 component: a long-acting agonist that works all day and carries the class boxed warning against a short-acting one that targets a single meal without it. Neither combination is a weight-loss product; the weight-loss GLP-1 brands and their pages, Wegovy and Zepbound, are where that evidence lives. For a log, the entry is product, date, units, and injection site; the liraglutide dose follows from the units and need not be recorded separately. How GLP-1 tracking works covers what to record.

7. Xultophy FAQ

• What does 100/3.6 mean?

  Concentration, not a dose. Each mL contains 100 units of insulin degludec and 3.6 mg of liraglutide. Dialling one unit delivers 1 unit of degludec and 0.036 mg of liraglutide, so 10 units is 10 units of insulin with 0.36 mg of liraglutide and 50 units is 50 units with 1.8 mg, the maximum Victoza dose.

• What is the Xultophy starting dose?

  10 units once daily for people not currently taking basal insulin or a GLP-1 agonist. 16 units once daily for people currently taking a basal insulin or a GLP-1 agonist, which is stopped when Xultophy starts. The pen dials in one-unit increments from 10 to 50. The dose is then adjusted by 2 units once or twice a week toward a fasting glucose target, up to a maximum of 50 units, which the label says not to exceed.

• When do you inject Xultophy?

  Once daily at the same time each day, with or without food. Both components are long-acting, degludec for more than a day and liraglutide for about 13 hours, so unlike Soliqua there is no meal rule. If a dose is missed, the label says to resume the once-daily schedule with the next dose, without doubling up; if more than 3 days have elapsed since the last dose, the label says to reinitiate at the recommended starting dose, and the Medication Guide tells patients to call their healthcare provider for instructions.

• How is Xultophy different from Soliqua?

  Different insulin and a different GLP-1 agonist. Xultophy is degludec plus liraglutide, dosed 10 to 50 units any time of day, and carries the thyroid C-cell boxed warning. Soliqua 100/33 is glargine plus lixisenatide, a short-acting agonist, dosed 15 to 60 units before the first meal, with no boxed warning.

• Does Xultophy cause weight gain?

  Less than insulin, more than liraglutide alone. In DUAL V, people switching from insulin glargine lost 1.4 kg on Xultophy over 26 weeks while those staying on glargine gained 1.8 kg. In DUAL III, people switching from a GLP-1 agonist gained 2.0 kg, because the insulin component was added.

• Is Xultophy the same as Tresiba or Victoza?

  No, but it is built from them. Xultophy 100/3.6 is Novo Nordisk's brand name for IDegLira, a fixed-ratio combination of the same insulin degludec sold alone as Tresiba and the same liraglutide sold alone as Victoza, in one daily pen. Tresiba doses in units with no upper label limit set by liraglutide; Victoza is dosed separately up to 1.8 mg. Xultophy locks the two together at 1 unit of degludec to 0.036 mg of liraglutide and caps the total at 50 units for that reason.

8. Sources