Comparing Weight-Loss Medications
This comparison reflects Dr. John Diaz's interpretation of the published clinical evidence below. It is provided for educational purposes only — it is not medical advice, a treatment recommendation, or a guarantee of results. Whether any medication is right for you is determined by a licensed provider. Individual results vary.
Comparison table
| Semaglutide Capsule | Tirzepatide Capsule | Semaglutide Injection | Tirzepatide Injection | Ozempic | Wegovy | Zepbound | |
|---|---|---|---|---|---|---|---|
| Compounded or branded ¹ | Compounded | Compounded | Compounded | Compounded | Brand | Brand | Brand |
| Form | Oral | Oral | Injection | Injection | Injection | Injection | Injection |
| Active ingredient | Semaglutide | Tirzepatide | Semaglutide | Tirzepatide | Semaglutide | Semaglutide | Tirzepatide |
| Other ingredients | Vitamin B12 | Vitamin B12 | Vitamin B12 | Vitamin B12 | — | — | — |
| Weight loss ² | + | + | ++ | +++ | ++ | ++ | ++++ |
| Cost ³ | $ | $$ | $ | $$ | $$$$ | $$$$$ | $$$ |
Weight loss: more + = greater average weight loss. Cost: more $ = higher typical cost.
¹ About compounded medications. Compounded medications are prepared by a state-licensed pharmacy based on an individual prescription. They are not FDA-approved, and the FDA does not review compounded drugs for safety, effectiveness, or quality before they are marketed.
² About the weight-loss ratings — please read. These ratings reflect the studied performance of each active ingredient (semaglutide or tirzepatide) in clinical trials of FDA-approved products, based on Dr. Diaz's interpretation of the published evidence cited below. They are general, relative indicators — not guarantees, and not individual predictions; individual results vary widely. Compounded products have not been studied for product-specific weight-loss effectiveness, and their results should not be assumed to match those of the approved medications. A rating shown for a compounded product reflects its active ingredient's studied performance, not proof that the compounded product achieves the same result.
³ Cost is a general relative indicator of typical cost and may vary.
What the evidence shows
(Web-organized version of Dr. Diaz's evidence summary — condensed for readability; full references below.)
Bottom line
- Ozempic and Wegovy both contain semaglutide; Zepbound contains tirzepatide.
- At the highest widely studied obesity doses, injectable tirzepatide generally produces the greatest average weight loss.
- In the head-to-head SURMOUNT-5 trial, tirzepatide produced 20.2% mean weight loss versus 13.7% with standard-dose Wegovy at 72 weeks — a 6.5-percentage-point difference [1].
- Standard injectable Wegovy (2.4 mg) and the studied oral semaglutide 25-mg tablet produce broadly similar average losses across separate trials, but have not been proven equivalent in a powered head-to-head study [4][6].
- Ozempic is usually less effective for weight loss than Wegovy because it uses lower semaglutide doses and was primarily studied in type 2 diabetes [7][8].
- The pivotal oral semaglutide product is a specially engineered tablet — not a generic capsule. There is no FDA-approved oral tirzepatide, and compounded capsules cannot be assumed to reproduce the results of approved formulations [9][11].
Strongest direct comparison: Zepbound vs. standard Wegovy (SURMOUNT-5)
In adults with obesity/overweight without diabetes, at 72 weeks, maximum-tolerated tirzepatide (10–15 mg) produced 20.2% mean weight loss vs. 13.7% for semaglutide (1.7–2.4 mg) — a 6.5-point difference favoring tirzepatide [1]. At a 200-lb starting weight, that corresponds to roughly 40 lb vs. 27 lb on average (group averages, not individual predictions).
Dose matters (SURMOUNT-1)
Tirzepatide showed a clear dose-response at 72 weeks: 5 mg → 15.0%, 10 mg → 19.5%, 15 mg → 20.9% [2]. The lowest maintenance dose overlaps with standard Wegovy's average.
Semaglutide formulations
- Standard Wegovy 2.4 mg: 14.9% at 68 weeks (STEP 1) [4].
- Higher-dose Wegovy 7.2 mg: ~18.7% (treatment-policy) / ~20.7% (on-treatment) at 72 weeks (STEP UP) [5]. No direct Zepbound comparison — numerical closeness is not proof of equivalence.
- Oral semaglutide 25 mg tablet: 13.6% at 64 weeks (~16.6% on-treatment) (OASIS 4) [6]. Requires specific fasting/water administration — one reason a compounded capsule can't be presumed equivalent [9].
Ozempic vs. Wegovy
Same molecule (semaglutide), but Ozempic uses lower, diabetes-focused doses. In STEP 2, semaglutide 2.4 mg gave ~9.6% vs. 7.0% at 1 mg vs. 3.4% placebo at 68 weeks [7]. Obesity-dose Wegovy generally produces more weight loss than Ozempic-dose semaglutide [8].
Compounded semaglutide and tirzepatide "capsules"
It would not be scientifically supportable to advertise a compounded capsule as producing a specific weight-loss percentage based on trials of the approved products, unless that exact compounded product had adequate pharmacokinetic, bioavailability, quality, and clinical-outcome evidence. There is no approved oral tirzepatide and no comparable pivotal obesity evidence for a tirzepatide capsule. The FDA notes compounded drugs are not FDA-approved or reviewed for safety, effectiveness, or quality, and has raised concerns about dosing errors and semaglutide salt forms that differ from approved products [11].
Practical mean-weight-loss ranking (for orientation)
| Rank | Treatment | Typical mean loss | Interpretation |
|---|---|---|---|
| 1 | Zepbound 10–15 mg injection | ≈20% | Strongest direct evidence of superiority over standard Wegovy |
| 2 | Wegovy HD 7.2 mg injection | ≈19% | Higher-dose semaglutide; no direct Zepbound comparison |
| 3 | Standard Wegovy 2.4 mg injection | ≈14–15% | Established obesity efficacy; extensive evidence |
| 4 | Oral semaglutide 25-mg tablet | ≈14% | ~17% on-treatment; adherence-sensitive |
| 5 | Ozempic 1–2 mg injection | ≈6–7% (diabetes trials) | Lower dose; different populations |
| 6 | Compounded semaglutide/tirzepatide capsules | Unknown | No reliable product-specific efficacy estimate |
Important qualification: Cross-trial percentages help with orientation but are not the same as head-to-head comparisons. Results vary by dose, diabetes status, duration, adherence, and analysis method. Tolerability, contraindications, adherence, availability, cost, and cardiometabolic factors may matter more for you than average differences between trial means.
Key references
- Aronne LJ, Horn DB, le Roux CW, et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity. N Engl J Med. 2025;393(1):26–36. https://doi.org/10.1056/NEJMoa2416394
- Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022;387(3):205–216. https://doi.org/10.1056/NEJMoa2206038
- Frías JP, Davies MJ, Rosenstock J, et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes. N Engl J Med. 2021;385:503–515. https://doi.org/10.1056/NEJMoa2107519
- Wilding JPH, Batterham RL, Calanna S, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021;384(11):989–1002. https://doi.org/10.1056/NEJMoa2032183
- Wharton S, Freitas P, Hjelmesæth J, et al. Once-weekly semaglutide 7.2 mg in adults with obesity: the STEP UP randomized trial. Lancet Diabetes Endocrinol. 2025;13(11):949–963. https://doi.org/10.1016/S2213-8587(25)00226-8
- Wharton S, Lingvay I, Bogdanski P, et al. Oral Semaglutide at a Dose of 25 mg in Adults with Overweight or Obesity. N Engl J Med. 2025;393(11):1077–1087. https://doi.org/10.1056/NEJMoa2500969
- Davies M, Færch L, Jeppesen OK, et al. Semaglutide 2.4 mg once a week in adults with overweight or obesity and type 2 diabetes: STEP 2. Lancet. 2021;397(10278):971–984. https://doi.org/10.1016/S0140-6736(21)00213-0
- Frías JP, Auerbach P, Bajaj HS, et al. Once-weekly semaglutide 2.0 mg versus 1.0 mg in type 2 diabetes: SUSTAIN FORTE. Lancet Diabetes Endocrinol. 2021;9(9):563–574. https://doi.org/10.1016/S2213-8587(21)00174-1
- U.S. Food and Drug Administration. Wegovy prescribing information (including the oral 25-mg tablet formulation).
- U.S. Food and Drug Administration. Approval information for higher-dose semaglutide 7.2 mg (Wegovy HD), March 19, 2026.
- U.S. Food and Drug Administration. FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss.
This page is an educational evidence synthesis reflecting Dr. John Diaz's professional interpretation of the published literature. It is not a substitute for individualized medical advice, current product labeling, or a review of contraindications and risks. Because formulations and regulatory status change, information is subject to update. Talk to your RxSpan MD provider about what is appropriate for you.