Two medicines, side by side
Diethylpropion vs phendimetrazine
Diethylpropion and phendimetrazine are both labeled for weight management. Drugs@FDA records approvals of diethylpropion since 1959 and of phendimetrazine since 1979. Pharmacies paid $0.238 per diethylpropion 25 mg tablet and $0.132 per phendimetrazine 35 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like.
Check it at the source: the diethylpropion FDA label on DailyMed (effective December 31, 2019); the phendimetrazine FDA label on DailyMed (effective December 6, 2024).
Highlights of the diethylpropion record
Diethylpropion (Tenuate) · label of December 31, 2019
Used for
From the label: indicationsDiethylpropion hydrochloride tablets USP, 25 mg are indicated in the management of exogenous obesity as a short-term adjunct (a few weeks) in a regimen of weight reduction based on caloric restriction in patients with an initial body mass index (BMI) of 30 kg/m 2 or higher and who have not responded to appropriate weight reducing regimen (diet and/or exercise) alone. […]
On the market
- Earliest approval on file
- August 6, 1959
- Generic labelers
- 13 labelers
- Pharmacy cost
- $0.238 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 2
Highlights of the phendimetrazine record
Phendimetrazine · label of December 6, 2024
Used for
From the label: indicationsPhendimetrazine tartrate is indicated in the management of exogenous obesity as a short term adjunct (a few weeks) in a regimen of weight reduction based on caloric restriction in patients with an initial body mass index (BMI) of 30 kg/m 2 or higher who have not responded to appropriate weight reducing regimen (diet and/or exercise) alone. Below is a chart of Body Mass Index (BMI) based on various heights and weights. […]
On the market
- Earliest approval on file
- April 16, 1979
- Generic labelers
- 11 labelers
- Pharmacy cost
- $0.132 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 0
Source: FDA drug labels via openFDA (Diethylpropion label of December 31, 2019, Phendimetrazine label of December 6, 2024); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do diethylpropion and phendimetrazine differ on the record?
Both are in FDA's class sympathomimetic amine anorectics.
Half-life, in each label's words: Diethylpropion, “Using a phosphorescence assay that is specific for basic compounds containing benzoyl group, the plasma half-life of …”; Phendimetrazine, “The average half-life of elimination when studied under controlled conditions is about 3.7 hours for both the …”
Generics: diethylpropion since 1979; phendimetrazine since 1975 (Drugs@FDA).
DEA schedule: diethylpropion CIV; phendimetrazine CIII.
| Diethylpropion | Phendimetrazine | |
|---|---|---|
| Labeled for | Weight management | Weight management |
| Pharmacologic class | Sympathomimetic Amine Anorectic | Sympathomimetic Amine Anorectic |
| How it works (label) | n/a | n/a |
| Half-life (label) | Using a phosphorescence assay that is specific for basic compounds containing benzoyl group, the plasma half-life of the aminoketone metabolites is estimated to be between 4 to 6 hours. | The average half-life of elimination when studied under controlled conditions is about 3.7 hours for both the extended-release and immediate release forms. |
| Earliest approval on file (Drugs@FDA) | August 6, 1959 | April 16, 1979 |
| First generic approved | August 15, 1979 | October 20, 1975 |
| Generic labelers (NDC) | 13 labelers | 11 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.238 per tablet (Diethylpropion 25 mg tablet) | $0.132 per tablet (Phendimetrazine 35 mg tablet) |
| 12-month price change | +12% | +4% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 2 | 0 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 127 | 57 |
| DEA schedule | CIV | CIII |
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 diethylpropion
- every medicine labeled for the same conditions