Why GLP-1s use a stepped dose schedule
Both semaglutide (Wegovy / Ozempic) and tirzepatide (Zepbound / Mounjaro) cause significant gastrointestinal side effects when started at full dose. Nausea, constipation, and fatigue are dose-dependent — start at full dose and most patients can't tolerate the medication.
The titration schedule exists to let your gut and brain adapt. Starting low (0.25 mg semaglutide or 2.5 mg tirzepatide) gets your body used to the molecule, and stepping up every 4 weeks lets the side effects ease before the next increase.
What to expect at each step
Semaglutide (Wegovy / compounded)
- Weeks 1–4 (0.25 mg): Side effects most prominent here — nausea, mild constipation, occasional fatigue. Appetite suppression starts within days but isn't dramatic yet.
- Weeks 5–8 (0.5 mg): Side effects often improve as your body adapts. Appetite suppression more noticeable.
- Weeks 9–12 (1.0 mg): Many patients plateau here for an extended period. Some clinicians hold patients at 1.0 mg for 8+ weeks before going up.
- Weeks 13–16 (1.7 mg): Significant appetite suppression and weight loss for most.
- Weeks 17+ (2.4 mg maintenance): Long-term dose for chronic weight management.
Tirzepatide (Zepbound / compounded)
- Weeks 1–4 (2.5 mg): Starting dose. Side-effect profile similar to semaglutide.
- Weeks 5–8 (5 mg): First titration. Many feel meaningful appetite changes here.
- Weeks 9–12 (7.5 mg): Effective dose for many patients.
- Weeks 13–16 (10 mg): Common maintenance dose.
- Weeks 17–20 (12.5 mg): Step up if response stalls.
- Weeks 21+ (15 mg): Maximum approved dose.
Side effects to expect (and what's actually concerning)
Common and usually fine
- Nausea, especially in the first 1–3 days after a dose
- Mild constipation (drink water, hit fiber, walk)
- Belching, mild reflux
- Reduced appetite (this is the point)
- Mild fatigue
Worth messaging your clinician about
- Vomiting that doesn't resolve in 24 hours
- Severe constipation or no bowel movements for 4+ days
- Sharp upper abdominal pain that radiates to the back (sign of pancreatitis — uncommon but serious)
- Vision changes
- Heart rate changes that feel abnormal
- Significant mood changes
Call 911 or go to ER
- Severe abdominal pain with vomiting
- Severe allergic reaction (rare but possible — hives, swelling, trouble breathing)
Why dose escalation isn't always linear
A good clinician will hold you at a step longer if:
- You're still losing weight at the current dose (no need to go higher)
- Side effects are still settling
- You're on the lower end of the BMI eligibility range
And will move you up if:
- Weight loss has stalled for 4+ weeks
- You're tolerating the current dose well
- You're far from your goal
If your program just runs every patient up the schedule on a fixed timer regardless of response, that's a sign of less individualized care.
Don't adjust your own dose
This sounds obvious but happens often. Reasons not to:
- Skipping doses doesn't "save" them — you're just delaying.
- Doubling up if you missed a dose isn't safer; the GI side effects come right back.
- Cutting your own dose in half because side effects are uncomfortable can lead to inconsistent absorption.
Message your clinician. They've handled every variation before and can adjust appropriately.