Tirzepatide

Tirzepatide is a dual GLP-1/GIP receptor agonist, meaning it hits two incretin pathways instead of one. In head-to-head trials, it outperformed semaglutide for both weight loss and blood sugar control. The brand names are Mounjaro (diabetes) and Zepbound (weight loss).

Dosing starts at 2.5 mg weekly and goes up to 15 mg. The titration schedule is similar to semaglutide: increase every 4 weeks as tolerated. Side effects overlap too, with nausea being the main one, though some people report it's milder than semaglutide.

Compounded tirzepatide typically comes in higher-concentration vials (up to 50 mg/mL), so getting your reconstitution math right matters more here than with most peptides.

Similar timeline to semaglutide. Appetite reduction within the first week, measurable weight loss by weeks 3 to 4.

The SURMOUNT trials showed average weight loss of 20 to 25% of body weight at the highest doses over 72 weeks, which is meaningfully better than semaglutide's numbers. Some people respond better to tirzepatide than semaglutide and vice versa, so switching is common if one doesn't work well.

GI side effects are the main ones: nausea, diarrhea, constipation, decreased appetite (which is kind of the point). Tends to be a bit gentler on the stomach than semaglutide for many people, though your mileage will vary.

Same caveats as semaglutide regarding hair thinning during rapid weight loss. Injection site reactions are occasionally reported. The thyroid C-cell tumor warning applies here too.

Same protocol as semaglutide: refrigerate at 36 to 46°F, good for about 28 days after reconstitution. Reconstitute with bacteriostatic water, swirl gently.

Because compounded tirzepatide often comes in high-concentration vials, pay extra attention to your water volume. A small error in reconstitution math at 50 mg/mL means a much bigger dosing error than with a 5 mg/mL vial.