TIRZEPATIDE

What is tirzepatide for weight loss?

Tirzepatide (Zepbound brand) is a once-weekly injection used for weight loss, weight management, and weight-related conditions, including obstructive sleep apnea (OSA). Tirzepatide works by reducing appetite, increasing the feeling of fullness, and slowing gastric emptying, which helps with weight loss.

For information about tirzepatide for type 2 diabetes, see here.

Tirzepatide is a GIP and GLP-1 receptor agonist.

Tirzepatide is self-administered as a subcutaneous injection using a single-dose pen, multi-dose KwikPen, or a vial with a syringe, and should always be used alongside a healthy diet and regular exercise.

Tirzepatide (Zepbound) Keypoints

• FDA-approved for weight management for adults with obesity, or overweight patients with weight-related conditions
• Prescription medicine
• Once-weekly injection
• Average 22.5% body-weight reduction for tirzepatide (15mg) over 72 weeks
• Not for use in type 1 diabetes
• Common side effects: nausea, diarrhea, vomiting

Who can use tirzepatide for weight loss?

• obesity, or
• overweight and have weight-related medical condition(s)Severe obstructive sleep apnea (OSA) in adults with obesity.

Tirzepatide for type 2 diabetes is FDA-approved under the brand name  Mounjaro for use in adults, together with diet and exercise. Tirzepatide should not be used in people with type 1 diabetes.

It is not known if tirzepatide can be used in people who have had pancreatitis.

Zepbound is a prescription medicine available as single-dose pens and single-dose vials in the strengths: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg per 0.5 mL.

How does tirzepatide work?

Tirzepatide is a GIP and GLP-1 receptor agonist and works like both of our natural hormones, GIP and GLP-1. Normally, when we eat, natural hormones called GIP and GLP-1 are released by the gut. 

Tirzepatide works by suppressing appetite, slowing gastric emptying, increasing the feeling of fullness, and increasing insulin release and insulin sensitivity. 

Tirzepatide works (mechanism of action) by activating both GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) hormone receptors.

How much weight can I lose on tirzepatide? 

Patients on tirzepatide (15mg) lost an average of 52 lbs  (22.5%) of their initial body weight over 72 weeks, compared to the placebo group, who lost an average of 5.3 lbs (2.4%) of their weight. These results were demonstrated in the clinical trial SURMOUNT-1 (NCT04184622). Individual results may vary. 

Tirzepatide vs. semaglutide weight loss: SURMOUNT-5 Clinical Trial Results 

Tirzepatide dual mechanism of action (GIP and GLP-1 receptor agonist) makes it significantly more effective than semaglutide for weight loss, which only activates GLP-1 receptors, as demonstrated in the head-to-head Surmount-5 clinical trial (NCT05822830), which reported an overall 47% greater weight loss with tirzepatide (Mounjaro, Zepbound) compared to semaglutide. 

• Average weight loss: 50.3 lbs with tirzepatide vs. 33.1 lbs with semaglutide
• Average % Weight loss: 20.2% with tirzepatide vs.13.7% with semaglutid
• Waist size reduction: 7.2 inches with tirzepatide vs. 5.1 inches with semaglutide.

The Surmount-5 trial was a compared tirzepatide to semaglutide for weight loss over a 72-week treatment period at their maximum tolerated doses.

Tirzepatide side effects

Common tirzepatide side effects

The most common tirzepatide side effects include abdominal pain, burping, constipation, diarrhea, dyspepsia, fatigue, gastroesophageal reflux disease, hair loss, hypersensitivity reactions, injection site reactions, nausea, and vomiting, which affect 5% or more patients.

Serious tirzepatide side effects

Tirzepatide can cause serious side effects. Call your doctor at once if you have:

• severe stomach problems, if you have severe pain in your stomach area (abdomen) that will not go away, with or without vomiting, or you may feel the pain from your abdomen to your back;
• dehydration leading to kidney problems. Diarrhea, nausea, and vomiting may cause a loss of fluids (dehydration) which may cause kidney problems. It is important for you to drink fluids to help reduce your chance of dehydration. 
• gallbladder problems with symptoms including chalky-colored stools, stomach yellowing of skin or eyes (jaundice), fever, and severe upper stomach;
• pancreas inflammation (pancreatitis). Stop using this medicine and call your healthcare provider right away if you have severe pain in your stomach area (abdomen) that will not go away, with or without vomiting. You may feel the pain from your abdomen to your back. 
• serious allergic reactions, see above
• low blood sugar symptoms (hypoglycemia) may include headache, hunger, weakness, sweating, confusion, irritability, dizziness, fast heart rate, or feeling jittery; or
• eye side effects or vision changes in patients with type 2 diabetes, including blurry vision or blurred vision or any other vision changes
• signs of a thyroid tumor symptoms may include swelling or a lump in your neck, trouble swallowing, a hoarse voice, or if you feel short of breath;
• depression or thoughts of suicide. You should pay attention to any changes in your mood, behaviors, feelings, or thoughts. Call your healthcare provider right away if you have any changes to your mental health that are new, worse, or worry you. 
• food or liquid getting into the lungs during surgery or other procedures that use anesthesia or deep sleepiness (deep sedation). This medicine may increase the chance of food getting into your lungs during surgery or other procedures. Tell all your healthcare providers that you are taking Zepbound before you are scheduled to have surgery or other procedures.