GLP-1 and GIP Medicines for Type 2 Diabetes

Why does type 2 diabetes develop?

Insulin is a hormone made by the pancreas. It helps sugar move from the blood into muscles and other tissues so the body can use it for energy.

Two problems often occur together in type 2 diabetes: the body responds less well to insulin (insulin resistance), and the pancreas cannot make enough insulin for the body's needs. The balance differs between people, so treatment depends on blood sugar, body size and overall health.

Semaglutide and tirzepatide help the pancreas release insulin when blood sugar is high and also affect appetite and weight. They can be an option for people with type 2 diabetes who have excess weight and insulin resistance and need to improve both blood sugar and weight.

What are GLP-1 and GIP?

GLP-1 and GIP are hormones released by the gut after eating. They help the pancreas release insulin in response to higher blood sugar.

GLP-1 also helps prevent the liver from releasing too much sugar, slows the movement of food out of the stomach and reduces appetite. GIP helps insulin release after a meal. These medicines use the actions of these naturally occurring hormones.

How do the two medicines differ?

Both products discussed here are once-weekly injections for type 2 diabetes. The clinician chooses the medicine and dose after considering the response and side effects.

• Semaglutide (Ozempic) uses the action of GLP-1.
• Tirzepatide (Mounjaro) uses the actions of both GIP and GLP-1.

How much can blood sugar and weight improve?

HbA1c is a blood test that reflects blood sugar over roughly the previous one to two months. In the 40-week SURPASS-2 trial in people with type 2 diabetes, the average decreases were:

• Semaglutide 1 mg weekly: 1.86%.
• Tirzepatide 5 mg weekly: 2.01%.
• Tirzepatide 10 mg weekly: 2.24%.
• Tirzepatide 15 mg weekly: 2.30%.

How are the injections used?

Both are generally injected once a week on the same day, under the skin of the abdomen, thigh or another instructed site. A doctor, nurse or pharmacist will explain the device. Treatment starts at a low dose.

• Semaglutide (Ozempic): 0.25 mg weekly for four weeks, then usually 0.5 mg. If the response is insufficient after at least four weeks at 0.5 mg, the clinician may increase it to a maximum of 1 mg weekly for this Japanese diabetes product.
• Tirzepatide (Mounjaro): 2.5 mg weekly for four weeks, then usually 5 mg. If needed, the clinician may increase it by 2.5 mg at intervals of at least four weeks, up to 15 mg weekly.

Can these medicines help protect the kidneys?

In the FLOW trial, 3,533 people with type 2 diabetes, reduced kidney function and albumin leaking into their urine received semaglutide 1 mg weekly or placebo. Over a median of 3.4 years, semaglutide reduced the relative risk of a combined outcome of kidney failure, a major decline in kidney function, or death from kidney or cardiovascular disease by 24%. Kidney function also declined more slowly. This trial was designed primarily to test kidney outcomes.

A 2026 kidney analysis of SURPASS-CVOT studied people with type 2 diabetes and established cardiovascular disease. Over about four years, tirzepatide reduced the relative risk of a combined outcome of persistent high urine albumin, a major decline in kidney function, end-stage kidney disease or kidney-related death by 23% compared with dulaglutide. This was a planned exploratory analysis within a trial primarily studying cardiovascular outcomes.

Side effects and when to seek help

Common side effects include nausea, vomiting, diarrhea, constipation, abdominal discomfort and reduced appetite, particularly when starting or increasing the dose. Contact the clinic if symptoms persist or are difficult to tolerate.

Low blood sugar is more likely when these medicines are combined with insulin or certain diabetes tablets. Ask in advance what to do if you develop sweating, shaking or palpitations.

• Seek prompt medical care for severe persistent abdominal pain or repeated vomiting.
• Seek care for constipation with a swollen, painful abdomen, or right upper abdominal pain, fever or yellow skin or eyes.
• Contact a clinician if you cannot drink, pass much less urine or feel very dizzy. Dehydration can affect kidney function.
• Call 119 for breathing difficulty, swelling of the face or throat, or reduced consciousness.

References and related information

Updated September 8, 2026. This is general information; individual treatment is decided after a medical assessment.