Non-Responder Decision Algorithm
Structured pathway for GLP-1 weight-management patients who do not achieve clinically meaningful weight loss at 16 weeks.
Draft โ requires medical reviewer signoff
This protocol is a draft requiring licensed-physician review before clinical application.
Defining Non-Response
| Response category | Threshold at 16 weeks | Action |
|---|---|---|
| Super-responder | โฅ15% weight loss | Continue. Consider dose maintenance over escalation. |
| Good responder | 8โ15% weight loss | Continue current regimen. Complete titration if not at max. |
| Partial responder | 5โ8% weight loss | Continue with lifestyle intensification; consider GH secretagogues for lean mass. |
| Non-responder | <5% weight loss | Enter the decision algorithm below. |
| Severe non-responder | <2% weight loss | Faster decision; consider class switch earlier. |
Pre-Switch Checklist โ Rule Out Confounders
Before declaring non-response, verify:
- Adherence โ actual medication uptake
- Titration completion โ at max-tolerated dose for โฅ8 weeks
- Confounding medications โ SSRIs, atypical antipsychotics (mirtazapine, olanzapine), anticonvulsants (pregabalin)
- Sleep โ undiagnosed OSA (STOP-BANG screen)
- Mental health โ depression + binge eating disorder (PHQ-9, EDE-Q)
- Thyroid โ recheck TSH
- Cortisol โ rule out Cushing features
- Caloric intake โ paradoxical under-eating
- Resistance training โ without stimulus, body composition plateaus
- Protein intake โ below 1.2 g/kg body weight
~40% of apparent non-responders resolve with confounder correction.
Algorithm
flowchart TD
A[16-week assessment: <5% loss] --> B{At max tolerated dose โฅ8 weeks?}
B -->|No| C[Complete titration<br/>Reassess]
B -->|Yes| D{Confounders present?}
D -->|Yes| E[Address confounders first]
D -->|No| F{Current agent}
F -->|Semaglutide| G[Switch to tirzepatide]
F -->|Tirzepatide| H{BMI โฅ40 or โฅ35 + comorbidity?}
H -->|Yes| I[Bariatric surgery consult]
H -->|No| J[Add lean-mass stack<br/>Consider Tesamorelin]
Class Switch โ Semaglutide โ Tirzepatide
Evidence supports tirzepatide achieving weight loss in semaglutide non-responders. Different receptor profile (GIP + GLP-1 vs. GLP-1 alone) means non-response to one does not predict non-response to the other.
Approach:
- Hold semaglutide
- 2โ4 week washout optional
- Start tirzepatide at 2.5 mg per FDA titration
- Reassess at 16 weeks
Related Peptides
Related Conditions
Supporting Evidence
| Claim | Source | PMID | Evidence Level |
|---|---|---|---|
| ~10-15% non-response rate at 16 weeks on GLP-1 | STEP 1 subgroup analysis | 33567185 | I |
| Tirzepatide achieves response post-semaglutide exposure | SURMOUNT-1 | 35658024 | I |
| Weight regain magnitude on discontinuation | STEP 4 / SURMOUNT-4 | 33755728 / 38078870 | I |
Referenced in: Module 5 Lesson 5.8