Tirzepatide is a prescription medicine that can quiet hunger. What benefits did the shot bring, and what harm occurred?

What does Tirzepatide offer, and where are the limits?

Tirzepatide copies hormones, chemicals the body sends to carry messages. This page covers weight changes and the harms treatment can bring. Its 39-amino-acid chain joins small parts also found in proteins. The medicine copies two hormones released after meals, GIP and GLP-1.

Your pancreas, a gland near the stomach, makes insulin. Insulin helps move sugar from blood into the body's cells. Tirzepatide delays the stomach emptying after meals, so hunger can ease. Early tests found greater energy burning as well.

Adults lost 20.9% of their weight, on average, over 72 weeks. That loss exceeded earlier approved weight medicines in large studies ^[4]. In another study, tirzepatide patients lost more weight than semaglutide patients ^[5]. Your own weight loss may be smaller or larger than those averages.

In May 2022, approval first covered adults with type 2 diabetes. November 2023 added approval for weight care in qualifying adults. Approval later included sleep apnea with obesity, meaning harmful excess weight. With sleep apnea, breathing repeatedly pauses while a person sleeps.

Most people tolerated treatment, though stomach trouble sometimes ended care early. Feeling sick was a frequent reason for stopping the shots. The Tirzepatide effects page explains reported benefits and unwanted effects.

What happened when people continued or stopped the shots?

SURMOUNT-1 studied 2,539 adults with excess weight over a 72-week period. Some had obesity; others had overweight and a weight-related illness. This phase 3 study was a large test of treatment. People received either tirzepatide or placebo, a shot without the medicine.

Chance chose the treatment, hidden from patients and study staff. Milligrams describe the amount of medicine inside each shot. After 72 weeks, the 5 milligram group had lost 15.0%, on average ^[4].

The 10 milligram group lost an average 19.5% of starting weight. With 15 milligrams, average weight loss reached 20.9%. The placebo group lost 3.1% of starting weight, on average.

At the largest amount, more than half lost at least 20%. That's a fifth or more of the weight before treatment. Such large losses hadn't appeared in earlier major weight studies.

SURMOUNT-4 began with a 36-week period when everyone received tirzepatide. Average weight loss reached 20.9% before some people changed to placebo. At week 88, continued medicine had brought another 5.5% loss. The group changed to placebo had regained 14.0% ^[9].

Ending treatment brought back a large share of the lost weight. Continued medicine helped people hold onto the earlier weight loss. The Tirzepatide research page follows these studies in greater detail.

2026: SURMOUNT-MAINTAIN examined continuing treatment with 5 milligrams each week. People changed treatment at week 60 and were followed to week 112. Total loss was 16.6% with 5 milligrams, against 9.9% with placebo ^[12]. Continuing at the lower amount preserved much of the loss.

What did Tirzepatide results show against semaglutide?

2025: SURMOUNT-5 compared weight treatment in 751 adults with obesity. Nobody had type 2 diabetes, and everyone knew their assigned medicine. Chance chose which medicine each person received during the study.

Tirzepatide shots held 10 or 15 milligrams, according to side effects. The semaglutide amounts were 1.7 or 2.4 milligrams on that basis. A milligram measures medicine, rather than the weight someone loses. At 72 weeks, average losses were 20.2% for tirzepatide and 13.7% for semaglutide ^[5].

Waists also shrank more among the people receiving tirzepatide. Weight falls of at least 10%, 15%, 20%, or 25% occurred more often. This was the first large weight study comparing these medicines directly. The tirzepatide weight loss page gives the fuller results.

SURPASS-2 instead studied adults who had type 2 diabetes. Their blood test measured average sugar across roughly three months. At week 40, tirzepatide 15 milligrams lowered sugar more than semaglutide 1 milligram ^[3]. Weight fell more with every tirzepatide amount tested as well.

The better average doesn't decide which medicine suits your health. Other illnesses, other medicines, and unwanted effects all affect that choice. The papers for these comparisons appear under Tirzepatide references.

Why does the Tirzepatide peptide remain between weekly shots?

This peptide contains a 39-amino-acid chain, made from small protein parts. Peptides consist of joined small parts of the kind found in proteins. This chain copies GIP, a hormone released when food arrives. An attached fatty part clings to a protein in blood ^[7].

The medicine stays attached to that protein, so removal is slower. Blood held roughly half after five days, supporting weekly treatment. The approved shots deliver medicine beneath the skin, where entry is slow.

In cells grown in dishes, tirzepatide copied both meal-hormone effects. Researchers measured chemical messages inside cells responding to GIP and GLP-1 ^[2]. The GIP response was stronger; these weren't blood-sugar readings in people. Another GLP-1 test examined messages prompting insulin release or dulling hormone responses.

Tirzepatide favoured the insulin-release message over the message that dulls cell responses. That could keep cells responding longer, though treated people weren't tested here. Researchers also proposed fewer unwanted effects, which these tests didn't prove.

In mice, the combined effects outperformed copying GLP-1 alone ^[1]. More insulin was released when sugar was high. A separate sugar-raising hormone also had less effect during treatment.

Food left the stomach more slowly, and hunger became less pressing. The what is tirzepatide page connects early tests with later studies. Your prescriber weighs the possible benefits against the risks to your health.

Which problems accompanied the benefits in these studies?

Weight and diabetes studies most often found stomach trouble ^[4]. People felt sick, vomited, had loose stools, or became constipated. Medicine increases often brought trouble, usually mild or moderate. A review of 13 weight studies found more trouble than placebo ^[10].

Placebo contains no tirzepatide, allowing doctors to compare treatment groups. Animal tumours led to a warning about the thyroid gland ^[6]. That neck gland helps control how the body uses energy. The animal tests don't establish that people face the same tumour risk.

Medullary thyroid carcinoma is a particular kind of thyroid cancer. That cancer in a patient's or relative's history rules out treatment. Multiple Endocrine Neoplasia syndrome type 2 also rules out treatment. Children can inherit this illness, which causes tumours in hormone-making glands.

Nine studies involving 9,871 people found extra gallbladder or drainage-tube illness ^[8]. The gallbladder stores fluid that helps break down fat. The paper's 95% confidence range supported extra risk despite some uncertainty. That range describes doubt about how much extra risk occurred.

Pancreas inflammation means swelling and irritation of the insulin-making gland. Its separate 95% range couldn't settle whether treatment increased the risk. Cases remain a label warning, so doctors still consider pancreas illness. Your risks are discussed further on the Tirzepatide effects page.