Tirzepatide was originally developed to treat Type-2 diabetes but has since become a leading anti-obesity medication. It is a dual agonist of the GLP-1 and GIP receptors — meaning it activates two distinct hormonal pathways to reduce appetite, improve metabolic rate, and support sustained weight loss.

Unlike its predecessor Semaglutide (which only targets GLP-1), Tirzepatide showed 5–7% more weight loss in clinical trials. Compared to Retatrutide, a triple agonist, Tirzepatide accomplished nearly the same weight loss but over a longer period (72 weeks vs. 48).

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MECHANISM OF ACTION

• GLP-1: Suppresses appetite and increases feelings of fullness after eating.

• GIP: Promotes insulin secretion and supports energy balance through receptors in the hypothalamus.

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BENEFITS

• Average weight loss of 24.7% after 72 weeks

• Reduces appetite and cravings

• Enhances satiety and energy balance

• Supports fat oxidation and metabolism

• Improves insulin sensitivity and blood sugar control

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POSSIBLE SIDE EFFECTS (often mild and temporary; affected only ~25% in trials)

• Injection site reaction (redness, swelling, itching)

• Nausea

• Vomiting

• Diarrhea

• Constipation

• Decreased appetite

• Fatigue

• Dyspepsia (indigestion)

• Abdominal pain

• Burping (may have sulfur smell)

• Hair loss

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RARE BUT SERIOUS RISKS

• Thyroid C-Cell Tumors

• Pancreatitis

• Gastroparesis (stomach paralysis)

• Hypoglycemia (if used with insulin)

• Gallbladder disease

• Kidney issues (linked to dehydration)

• Pulmonary aspiration under anesthesia – ALWAYS disclose Tirzepatide use to surgical teams

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INTERACTIONS

• Insulin and Insulin-stimulating drugs: includes all forms of insulin, sulfonylureas (glipizide, glyburide, glimepiride), and glinides (repaglinide), due to the increased risk of hypglycemia

• Oral medications: Tirzepatide may interfere the absorption of oral medications

• Oral birth control medications: increases the likelihood of additive GI effects, may lead to excessive appetite suppression, and increases the risk of hypoglycemia

• Growth hormone/GH analogs: interactions have been reported with Somatropin, Lonapegsomatropin, Somapacitan

• Alcohol: increases the risk of hypoglycemia and worsens nausea and dehydration

• Dehydration risk: dehydration places excessive stress on the kidneys, and may lead to kidney damage; this risk increases with concurrent use with ACE inhibitors, diuretics, ARB’s, and heart failure regimens

• Berberine/Metformin: increased risk of hypoglycemia

• Chromium/Insulin Sensitizers: increased risk of hypoglycemia

• Appetite suppressants: added risk of eating disorder/anorexia

• Stimulants: excessively diminished appetite and GI intolerance overlap

• Large, greasy meals: increases the likelihood of nausea

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PEPTIDE INTERACTIONS

SEVERE

• Other GLP peptides: Receptor redundancy and desensitization

• Tesamorelin: Elevated glucose levels

• IGF-1 LR3/DES and strong ghrelin agonists (e.g. GHRP 2 and 6): may oppose or significantly amplify Tirzepatide’s metabolic signaling

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MODERATE

• IGF-1 LR3 and IGF-1 DES: Risk of hypoglycemia and rapid glucose uptake

• CJC WITH DAC: Blunts GLP metabolic benefit

• GHRP-2, GHRP-6, Hexarelin: Can counter appetite suppression

• BAM-15: Watch appetite suppression and fatigue

• LL-37: May worsen nausea and inflammation

• Oxytocin: Monitor excessive appetite loss

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CONTRAINDICATIONS

• Do not use if pregnant or breastfeeding

• Do not use with a personal or family history of Medullary Thyroid Carcinoma or MEN 2 (Multiple Endocrine Neoplasia)

• Do not use if you have Type-1 diabetes, diabetic retinopathy, or severe GI disease

• Do not use if you are allergic or hypersensitive to Tirzepatide