Which GLP-1 produces the most weight loss?

Tirzepatide (Mounjaro/Zepbound) produces the greatest weight loss at approximately 22.5%, followed by semaglutide (Wegovy/Ozempic) at 15-17%. Liraglutide (Saxenda) achieves 8-9% weight loss. GLP-1s are superior to all older weight loss medications.

Is Ozempic the same as Wegovy?

Ozempic and Wegovy contain the same active ingredient (semaglutide) but differ in dosing. Ozempic is dosed for type 2 diabetes (0.5-1.0mg weekly) while Wegovy is dosed for weight loss (2.4mg weekly). Wegovy achieves greater weight loss due to higher dosing. Off-label use of Ozempic for weight loss uses Wegovy-level dosing.

What is the difference between Mounjaro and Zepbound?

Mounjaro (tirzepatide) is approved for type 2 diabetes while Zepbound is the identical medication approved for weight loss. They contain the same active ingredient and dosing (up to 15mg weekly). The distinction is merely regulatory and marketing.

Which GLP-1 has the best insurance coverage?

Insurance coverage varies by plan and employer. Semaglutide (Wegovy/Ozempic) may have slightly broader coverage due to longer market availability and diabetes indication. Many plans require prior authorization, step therapy, or BMI thresholds. Coverage for weight loss is improving but remains inconsistent.

Can you switch between different GLP-1s?

Yes, patients can switch between different GLP-1s, though a washout period and restart at lower doses is typically recommended. Switching from lower-efficacy GLP-1s (like liraglutide) to tirzepatide usually results in additional weight loss. Switching requires medical supervision.

What about other GLP-1s like dulaglutide or liraglutide?

Dulaglutide (Trulicity) and liraglutide (Saxenda) are older GLP-1s with lower weight loss efficacy (8-13%) compared to semaglutide and tirzepatide. Dulaglutide is dosed once weekly (like semaglutide/tirzepatide) but achieves less weight loss. These are rarely first-line choices for weight loss in 2026.

Which GLP-1 is Best for Weight Loss? 2026 Comparison Guide

GLP-1 receptor agonists represent a major breakthrough in weight loss treatment. This comprehensive guide compares all available GLP-1 medications, their efficacy, cost, insurance coverage, and ideal use cases.

GLP-1 Medications Overview

GLP-1 (glucagon-like peptide-1) agonists are a class of injectable medications originally developed for type 2 diabetes. These medications slow gastric emptying and increase satiety, leading to significant weight loss in the majority of patients.

As of 2026, the primary GLP-1 medications available in the United States are:

Tirzepatide (Mounjaro for diabetes, Zepbound for weight loss) — dual GLP-1/GIP agonist
Semaglutide (Ozempic for diabetes, Wegovy for weight loss) — GLP-1 agonist
Liraglutide (Victoza for diabetes, Saxenda for weight loss) — GLP-1 agonist
Dulaglutide (Trulicity) — GLP-1 agonist, primarily diabetes use

Additionally, combination medications like tirzepatide/GLP-1 plus other agents are in development, but the above four represent the current standard-of-care options.

Weight Loss Efficacy Comparison

Weight loss outcomes differ substantially between GLP-1 medications based on their mechanism and dosing.

Medication	Mechanism	Max Dose	Weight Loss %	Trial Name
Tirzepatide (15mg)	GLP-1/GIP agonist	15 mg weekly	22.5%	SURMOUNT-1
Semaglutide (2.4mg)	GLP-1 agonist	2.4 mg weekly	17.4%	STEP-4
Liraglutide (3.0mg)	GLP-1 agonist	3.0 mg daily	8.4%	SCALE
Dulaglutide (1.5mg)	GLP-1 agonist	1.5 mg weekly	4.5%	REWIND/AWARD

Key finding: Tirzepatide is 5.3 percentage points more effective than semaglutide (22.5% vs 17.4%), nearly triple the efficacy of liraglutide (8.4%), and five times more effective than dulaglutide (4.5%). This hierarchy is consistent across multiple large trials.

Tirzepatide (Mounjaro/Zepbound) — Most Effective

Tirzepatide is a dual GLP-1/GIP receptor agonist, the only medication with dual mechanism in this class. This dual action produces superior weight loss and potentially better metabolic effects.

Efficacy

Weight loss: 22.5% (SURMOUNT-1, 2,539 patients)
Patients achieving >20% weight loss: 61% at 15mg dose
Effect on HbA1c: −2.0 to −2.5% in diabetic patients

Dosing

Starting: 2.5mg weekly
Maintenance: 10mg or 15mg weekly
Titration: 16-20 weeks to reach maintenance
Frequency: Once weekly subcutaneous injection

Cost

Retail list price: $1,100-1,400/month
Insurance: Variable; increasingly covered for weight loss
Patient assistance: Available; can reduce cost to $0-250/month

Best for:

Patients wanting maximum weight loss
Patients with type 2 diabetes (dual benefits)
Patients who failed to achieve adequate loss on semaglutide

Semaglutide (Wegovy/Ozempic) — Most Studied

Semaglutide is a GLP-1-only agonist with the longest established safety data. It was approved for weight loss in 2021 and has the most published clinical trials.

Efficacy

Weight loss: 15-17% (STEP trials at 2.4mg dose)
Patients achieving >10% weight loss: 85% at 2.4mg dose
Effect on HbA1c: −1.0 to −1.5% in diabetic patients

Dosing

Starting: 0.25mg weekly
Maintenance: 1.7mg or 2.4mg weekly
Titration: 16-20 weeks to reach maintenance
Frequency: Once weekly subcutaneous injection

Cost

Retail list price: $900-1,400/month (similar to tirzepatide)
Insurance: Similar coverage patterns to tirzepatide
Patient assistance: Available through Novo Nordisk

Best for:

Patients prioritizing established long-term safety data
Patients with GI sensitivity (slower titration available)
Patients unable to afford or access tirzepatide

Liraglutide (Saxenda) — Budget/Legacy Option

Liraglutide was the first GLP-1 approved for weight loss (2014) but has been largely superseded by semaglutide and tirzepatide due to lower efficacy and daily dosing requirement.

Efficacy

Weight loss: 5-8% (SCALE trial)
Only about half as effective as semaglutide

Dosing

Starting: 0.6mg daily
Titration: Escalate by 0.6mg weekly to 3.0mg
Frequency: Daily subcutaneous injection (burden vs weekly alternatives)

Cost

Retail: $800-1,000/month
May have better insurance coverage (longer on market)
Often cheaper than tirzepatide/semaglutide due to patent expiry

Best for:

Patients with very limited budgets
Insurance plans that cover liraglutide but not semaglutide/tirzepatide
Rarely a first-choice given superior alternatives

Ozempic vs Wegovy: Same Drug, Different Indication

Ozempic (semaglutide for diabetes) and Wegovy (semaglutide for weight loss) are identical medications but marketed separately due to FDA regulatory approval pathways.

Key differences: Ozempic is typically dosed at 0.5-1.0mg weekly for diabetes control, while Wegovy reaches 2.4mg for weight loss. The higher Wegovy dosing produces greater weight loss than typical Ozempic dosing.

Off-label use: Some physicians prescribe Ozempic off-label at Wegovy-level doses (2.4mg) for weight loss, which costs less through some insurance plans than the branded Wegovy. This practice is legal but requires informed consent and off-label use acknowledgment.

Mounjaro vs Zepbound: Same Drug, Different Indication

Similar to semaglutide, tirzepatide is marketed as Mounjaro for type 2 diabetes and Zepbound for weight loss. Both products contain identical tirzepatide formulation dosed identically (up to 15mg weekly).

The only distinction is regulatory labeling and insurance billing codes. Clinical outcomes are identical regardless of which brand is prescribed.

Cost Comparison Table

Medication	Retail/Month	Typical Insurance	Patient Assistance	Copay Range
Tirzepatide (15mg)	$1,100-1,400	$150-400	$0-250	$50-200
Semaglutide (2.4mg)	$900-1,400	$150-400	$0-250	$50-200
Liraglutide (3.0mg)	$800-1,000	$100-300	$25-150	$25-100
Dulaglutide (1.5mg)	$600-900	$50-200	Free samples available	$10-100

Note: Costs vary substantially by insurance plan, geographic location, and individual negotiating circumstances. Patient assistance programs can dramatically reduce out-of-pocket costs for all medications.

Insurance Coverage Landscape 2026

Insurance coverage for GLP-1 weight loss medications has expanded significantly since 2023, but remains variable.

Medicare: Does not cover any GLP-1 for weight loss as of 2026 (covers for diabetes only). This is a major gap for seniors.

Commercial insurance: 70-80% of major plans now cover semaglutide and tirzepatide for weight loss with prior authorization. Most require BMI >27 with comorbidities or BMI >30 without comorbidities.

State Medicaid plans: Coverage varies widely by state. Some states cover tirzepatide/semaglutide while others do not.

Step therapy: Some insurance plans require patients to try liraglutide or dulaglutide first before covering semaglutide/tirzepatide, despite inferior efficacy.

Side Effect Profiles Comparison

All GLP-1s cause similar gastrointestinal side effects during titration. Tirzepatide shows slightly higher nausea/constipation rates, while liraglutide\'s daily dosing (rather than weekly) may result in different tolerability patterns.

Side Effect	Tirzepatide	Semaglutide	Liraglutide
Nausea	30-35%	25-29%	27-30%
Constipation	22-26%	15-18%	20-23%
Vomiting	8-12%	5-8%	6-9%
Discontinuation Rate	4.1%	4.3%	5-6%

Frequently Asked Questions

Recommendation Algorithm

First-line choice (2026): Tirzepatide 15mg weekly — superior efficacy, established safety, dual mechanism.

If tirzepatide unavailable or unaffordable: Semaglutide 2.4mg weekly — robust efficacy, excellent long-term data, similar cost.

If severe GI sensitivity: Semaglutide with extended titration (add 1-2 week intervals) or liraglutide.

If cost-prohibitive: Liraglutide or patient assistance programs for tirzepatide/semaglutide.

If insured by plan favoring dulaglutide: Negotiate for tirzepatide/semaglutide; dulaglutide\'s efficacy is inadequate compared to alternatives.

Summary and Conclusion

Tirzepatide (22.5% weight loss) is the most effective GLP-1 for weight loss, followed by semaglutide (17.4%), liraglutide (8.4%), and dulaglutide (4.5%). The superior efficacy of tirzepatide reflects its dual GLP-1/GIP mechanism compared to GLP-1-only alternatives.

Cost, insurance coverage, and tolerability should guide medication selection when efficacy differences are acknowledged. Patient assistance programs can make even expensive medications affordable.