Two medicines, side by side
Phentermine vs semaglutide
Phentermine and semaglutide are both labeled for weight management. Drugs@FDA records approvals of phentermine since 1973 and of semaglutide since 2017. Pharmacies paid $0.0727 per phentermine 37.5 mg tablet and $331.99 per mL (Ozempic 0.25-0.5 mg/dose (2 mg/3 mL) pen) (NADAC, October 7, 2026); the strengths differ and one is a brand and one a generic, so the two prices are not like for like. In FDA's classes, phentermine is a sympathomimetic amine anorectic and semaglutide a glp-1 receptor agonist.
Check it at the source: the phentermine FDA label on DailyMed (effective April 18, 2024); the semaglutide FDA label on DailyMed (effective July 30, 2026).
Highlights of the phentermine record
Phentermine (Lomaira) · label of April 18, 2024
Used for
From the label: indicationsPhentermine Hydrochloride, USP 15 mg and 30 mg is indicated as a short-term (a few weeks) adjunct in a regimen of weight reduction based on exercise, behavioral modification and caloric restriction in the management of exogenous obesity for patients with an initial body mass index greater than or equal to 30 kg/m 2 , or greater than or equal to 27 kg/m 2 in the presence of other risk factors (e.g., controlled hypertension, diabetes, hyperlipidemia). […]
On the market
- Earliest approval on file
- August 14, 1973
- Generic labelers
- 25 labelers
- Pharmacy cost
- $0.0727 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 9
Highlights of the semaglutide record
Semaglutide (Ozempic) · label of July 30, 2026
RISK OF THYROID C-CELL TUMORS
In rodents, semaglutide causes dose-dependent and treatment-duration-dependent thyroid C-cell tumors at clinically relevant exposures. It is unknown whether OZEMPIC causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans as human relevance of semaglutide-induced rodent thyroid C-cell tumors has not been determined [see Warnings and Precautions ( 5.1 ), Nonclinical Toxicology ( 13.1 )].
Used for
From the label: indicationsOZEMPIC is indicated: • as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. • to reduce the risk of major adverse cardiovascular events (cardiovascular death, non-fatal myocardial infarction or non-fatal stroke) in adults with type 2 diabetes mellitus and established cardiovascular disease. […]
On the market
- Earliest approval on file
- December 5, 2017
- Generic labelers
- none listed
- Pharmacy cost
- $331.99 per mL
Supply and safety
- Shortage
- A presentation being discontinued
- Recalls
- 4
Source: FDA drug labels via openFDA (Phentermine label of April 18, 2024, Semaglutide label of July 30, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do phentermine and semaglutide differ on the record?
In FDA's classes, phentermine is a sympathomimetic amine anorectic and semaglutide a glp-1 receptor agonist.
How each works, in its label's words: Phentermine, “Phentermine is a sympathomimetic amine with pharmacologic activity similar to the prototype drugs of this class used in obesity, amphetamine (d- and dll-amphetamine).”; Semaglutide, “Semaglutide acts as a GLP-1 receptor agonist that selectively binds to and activates the GLP-1 receptor, the target for native GLP-1.”
Only the semaglutide label carries a boxed warning.
Generics: phentermine since 1976; semaglutide none approved (Drugs@FDA).
DEA schedule: phentermine CIV; semaglutide none.
| Phentermine | Semaglutide | |
|---|---|---|
| Labeled for | Weight management | Type 2 diabetes, Heart attack and coronary artery disease, Chronic kidney disease, Weight management |
| Pharmacologic class | Sympathomimetic Amine Anorectic | GLP-1 Receptor Agonist |
| How it works (label) | Phentermine is a sympathomimetic amine with pharmacologic activity similar to the prototype drugs of this class used in obesity, amphetamine (d- and dll-amphetamine). | Semaglutide is a GLP-1 analogue with 94% sequence homology to human GLP-1. Semaglutide acts as a GLP-1 receptor agonist that selectively binds to and activates the GLP-1 receptor, the target for native GLP-1. |
| Half-life (label) | n/a | n/a |
| Earliest approval on file (Drugs@FDA) | August 14, 1973 | December 5, 2017 |
| First generic approved | February 24, 1976 | none |
| Generic labelers (NDC) | 25 labelers | none listed |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.0727 per tablet (Phentermine 37.5 mg tablet) | $331.99 per mL (Ozempic 0.25-0.5 mg/dose (2 mg/3 mL) pen) |
| 12-month price change | +3% | +3% |
| Boxed warning | No | Yes |
| Shortage now | No current entry | A presentation being discontinued |
| Recalls recorded | 9 | 4 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 6,389 | 73,001 |
| DEA schedule | CIV | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
What next?
- Alternatives to phentermine
- every medicine labeled for the same conditions