Two medicines, side by side
Finasteride vs tadalafil
Finasteride and tadalafil are both labeled for enlarged prostate (bph). Drugs@FDA records approvals of finasteride since 1992 and of tadalafil since 2003. Pharmacies paid $0.0688 per finasteride 5 mg tablet and $0.167 per tadalafil 20 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. In FDA's classes, finasteride is a 5-alpha reductase inhibitor and tadalafil a phosphodiesterase 5 inhibitor.
Check it at the source: the finasteride FDA label on DailyMed (effective March 18, 2026); the tadalafil FDA label on DailyMed (effective June 3, 2026).
Highlights of the finasteride record
Finasteride (Proscar) · label of March 18, 2026
Used for
From the label: indicationsPROSCAR, is a 5α-reductase inhibitor, indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate to ( 1.1 ): Improve symptoms Reduce the risk of acute urinary retention Reduce the risk of the need for surgery including transurethral resection of the prostate (TURP) and prostatectomy. […]
On the market
- Earliest approval on file
- June 19, 1992
- Generic labelers
- 30 labelers
- Pharmacy cost
- $0.0688 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 6
Highlights of the tadalafil record
Tadalafil (Cialis) · label of June 3, 2026
Used for
From the label: indicationsCIALIS ® is a phosphodiesterase 5 (PDE5) inhibitor indicated for the treatment of: erectile dysfunction (ED) ( 1.1 ) the signs and symptoms of benign prostatic hyperplasia (BPH) ( 1.2 ) ED and the signs and symptoms of BPH (ED/BPH) ( 1.3 ) If CIALIS is used with finasteride to initiate BPH treatment, such use is recommended for up to 26 weeks ( 1.4 ). 1.1 Erectile Dysfunction CIALIS ® is indicated for the treatment […]
On the market
- Earliest approval on file
- November 21, 2003
- Generic labelers
- 49 labelers
- Pharmacy cost
- $0.167 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 12
Source: FDA drug labels via openFDA (Finasteride label of March 18, 2026, Tadalafil label of June 3, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do finasteride and tadalafil differ on the record?
In FDA's classes, finasteride is a 5-alpha reductase inhibitor and tadalafil a phosphodiesterase 5 inhibitor.
How each works, in its label's words: Finasteride, “The development and enlargement of the prostate gland is dependent on the potent androgen, 5α-dihydrotestosterone (DHT).”; Tadalafil, “Penile erection during sexual stimulation is caused by increased penile blood flow resulting from the relaxation of penile arteries and corpus cavernosal smooth muscle.”
Half-life, in each label's words: Finasteride, “Excretion In healthy young subjects (n=15), mean plasma clearance of finasteride was 165 mL/min (range, 70-279 mL/min) …”; Tadalafil, “Excretion – The mean oral clearance for tadalafil is 2.5 L/hr and the mean terminal half-life is 17.5 hours in healthy …”
Generics: finasteride since 2006; tadalafil since 2018 (Drugs@FDA).
| Finasteride | Tadalafil | |
|---|---|---|
| Labeled for | Enlarged prostate (BPH) | Erectile dysfunction, Enlarged prostate (BPH), Pulmonary arterial hypertension |
| Pharmacologic class | 5-alpha Reductase Inhibitor | Phosphodiesterase 5 Inhibitor |
| How it works (label) | The development and enlargement of the prostate gland is dependent on the potent androgen, 5α-dihydrotestosterone (DHT). Type II 5α-reductase metabolizes testosterone to DHT in the prostate gland, liver and skin. | Penile erection during sexual stimulation is caused by increased penile blood flow resulting from the relaxation of penile arteries and corpus cavernosal smooth muscle. |
| Half-life (label) | Excretion In healthy young subjects (n=15), mean plasma clearance of finasteride was 165 mL/min (range, 70-279 mL/min) and mean elimination half-life in plasma was 6 hours (range, 3-16 hours). | Excretion – The mean oral clearance for tadalafil is 2.5 L/hr and the mean terminal half-life is 17.5 hours in healthy subjects. |
| Earliest approval on file (Drugs@FDA) | June 19, 1992 | November 21, 2003 |
| First generic approved | June 19, 2006 | May 22, 2018 |
| Generic labelers (NDC) | 30 labelers | 49 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.0688 per tablet (Finasteride 5 mg tablet) | $0.167 per tablet (Tadalafil 20 mg tablet) |
| 12-month price change | -1% | -19% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 6 | 12 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 59,983 | 99,551 |
| DEA schedule | none | 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 finasteride
- every medicine labeled for the same conditions