The Quick Answer
Both semaglutide and tirzepatide are highly effective GLP-1 medications for medical weight loss. Clinical trials show tirzepatide produces slightly greater average weight loss (~20% body weight vs ~15% for semaglutide), but semaglutide has a longer track record and may be better tolerated by some patients. Both are excellent options — the best choice depends on your goals, health history, and budget.
What Are These Medications?
Both drugs belong to a class called GLP-1 receptor agonists — they mimic hormones that regulate appetite and blood sugar, helping you feel full sooner and eat less.
- Semaglutide (brand names: Ozempic for diabetes, Wegovy for weight loss) — activates GLP-1 receptors only. Originally developed for type 2 diabetes, now widely used for weight management.
- Tirzepatide (brand names: Mounjaro for diabetes, Zepbound for weight loss) — activates both GLP-1 and GIP receptors (dual agonist). The dual mechanism is believed to explain its greater efficacy.
Efficacy Comparison
| Factor | Semaglutide | Tirzepatide |
|---|---|---|
| Average weight loss | ~15% body weight | ~20% body weight |
| FDA approval (weight loss) | Yes (Wegovy, 2021) | Yes (Zepbound, 2023) |
| Mechanism | GLP-1 only | GLP-1 + GIP dual |
| Injection frequency | Once weekly | Once weekly |
| Time to max results | 12–18 months | 12–18 months |
| Years on market | 5+ years | 2+ years |
Side Effects: Which Has Fewer?
Both medications share similar GI side effects — nausea, vomiting, diarrhea, and constipation — especially when starting or increasing doses. These typically improve significantly after 4–8 weeks as your body adjusts.
- Semaglutide: GI side effects reported in ~40–45% of patients, usually mild-moderate
- Tirzepatide: Slightly higher GI side effect rate at higher doses, but similar long-term tolerability
- Both carry rare risks of pancreatitis and thyroid tumors — your provider will monitor accordingly
Your med spa provider will use a slow dose titration protocol to minimize side effects.
Cost Comparison at Med Spas
| Medication | Med Spa (Compound) | Brand Name |
|---|---|---|
| Semaglutide | $299–$499/month | $900–$1,400/month (Wegovy) |
| Tirzepatide | $399–$599/month | $650–$1,000/month (Zepbound) |
Compounded versions use the same active molecule, manufactured by FDA-registered compounding pharmacies. They are not FDA-approved drugs but are widely prescribed when brand-name supply is limited.
Which Should You Choose?
Use this decision framework:
- Budget is the priority → Semaglutide compound ($299–$499/mo) is typically $100/mo cheaper than tirzepatide
- Maximum weight loss matters most → Tirzepatide's dual mechanism produces ~5% more weight loss on average
- You have type 2 diabetes → Discuss with your provider; both were developed for diabetes management
- You're sensitive to GI side effects → Start with semaglutide at lowest dose, with careful titration
- You've tried semaglutide without success → Tirzepatide's different mechanism may work better for you
Where to Get GLP-1 Treatment
Both medications are available at thousands of med spas across the US. Many providers offer telehealth consultations with same-week prescription turnaround.
Find verified GLP-1 providers near you: GLP-1 Weight Loss at Med Spas: Complete Guide or browse semaglutide providers by city.