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).

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.

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

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

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

INTERACTIONS

• Insulin and Insulin-stimulating drugs: increased risk of hypoglycemia
• Oral medications: Tirzepatide may interfere with absorption of oral medications
• Oral birth control medications: may lead to excessive appetite suppression
• Growth hormone/GH analogs: interactions reported with Somatropin, Lonapegsomatropin, Somapacitan
• Alcohol: increases risk of hypoglycemia and worsens nausea
• Berberine/Metformin: increased risk of hypoglycemia
• Appetite suppressants: added risk of eating disorder
• Stimulants: excessively diminished appetite
• Large, greasy meals: increases likelihood of nausea

PEPTIDE INTERACTIONS

SEVERE

• Other GLP peptides: Receptor redundancy and desensitization
• Tesamorelin: Elevated glucose levels
• IGF-1 LR3/DES and strong ghrelin agonists: may oppose or amplify Tirzepatide's metabolic signaling

MODERATE

• IGF-1 LR3 and IGF-1 DES: Risk of hypoglycemia
• 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

CONTRAINDICATIONS

• Do not use if pregnant or breastfeeding
• Do not use with a personal or family history of Medullary Thyroid Carcinoma or MEN 2
• 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