Propecia vs Synthroid: side-by-side comparison
Propecia (Alopécie androgénétique) and Synthroid (Hormones et contraception) belong to different therapeutic classes and are rarely interchangeable. This page compares the medications' purposes, mechanisms and the situations where each is used.
| Property | Propecia | Synthroid |
|---|---|---|
| Active ingredient | Finasteride | Levothyroxine |
| Manufacturer | Merck | AbbVie |
| Class | Alopécie androgénétique | Hormones et contraception |
| Strengths | 1mg | 25mcg, 50mcg, 75mcg, 100mcg, 150mcg |
| Forms | tablet | tablet |
What's the same
Propecia and Synthroid are used in very different patients, and the points in common are limited. The main shared element is that both meet regulatory standards for efficacy and safety and benefit from pharmacist oversight.
Key differences
Propecia belongs to Alopécie androgénétique while Synthroid belongs to Hormones et contraception. Indications, mechanisms and target populations differ. The comparison is most useful when a clinician has mentioned both medications and the patient wants to understand where each fits.
Mechanism and action
Propecia: La DHT, produite à partir de la testostérone par la 5-alpha-réductase, entraîne la miniaturisation des follicules pileux du cuir chevelu chez les hommes génétiquement prédisposés, raccourcissant progressivement les phase… Synthroid: La lévothyroxine remplace la thyroxine endogène déficitaire, convertie dans les tissus en hormone active, la triiodothyronine (T3), par les enzymes désiodases.
When Propecia is preferred
Propecia est autorisé dans le traitement de l'alopécie androgénétique masculine chez l'homme de 18 à 41 ans.
When Synthroid is preferred
Synthroid est autorisé dans l'hypothyroïdie de toute cause (thyroïdite de Hashimoto, post-thyroïdectomie, post-iode radioactif, congénitale), dans le goitre et dans la freination de la TSH après cancer thyroïdien différencié.
Questions fréquentes
Is Propecia or Synthroid better? ▾
Propecia and Synthroid are not interchangeable — they treat different conditions. Asking which is "better" is meaningful only when a clinician has weighed both for the same specific clinical scenario.
Can I switch from Propecia to Synthroid? ▾
Switching between Propecia and Synthroid is rarely an appropriate decision since they belong to different classes and treat different conditions. The real question is usually whether the diagnosis calls for one medication or the other — which the prescriber resolves.
Do Propecia and Synthroid have the same side effects? ▾
No — they belong to different classes and have distinct side-effect profiles. Each medication has its own prescribing information.
More Propecia comparisons
Les informations publiées sur ce site sont fournies à titre documentaire et pédagogique. Elles ne remplacent pas l'avis d'un professionnel de santé qualifié.