Avodart vs Synthroid: side-by-side comparison
Avodart (Male and Female Pattern Hair Loss) and Synthroid (Hormones and Birth Control) belong to different therapeutic classes and are rarely interchangeable. This page compares the medications' purposes, mechanisms and the situations where each is used.
| Property | Avodart | Synthroid |
|---|---|---|
| Active ingredient | Dutasteride | Levothyroxine |
| Manufacturer | GlaxoSmithKline | AbbVie |
| Class | Male and Female Pattern Hair Loss | Hormones and Birth Control |
| Strengths | 0.5mg | 25mcg, 50mcg, 75mcg, 100mcg, 150mcg |
| Forms | capsule | tablet |
What's the same
Avodart 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
Avodart belongs to Male and Female Pattern Hair Loss while Synthroid belongs to Hormones and Birth Control. 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
Avodart: Avodart inhibits both isoforms of 5α-reductase, the enzyme that converts testosterone to dihydrotestosterone (DHT). Synthroid: Levothyroxine replaces deficient endogenous thyroxine, which is converted in tissues to the active hormone triiodothyronine (T3) by deiodinase enzymes.
When Avodart is preferred
Avodart is approved for the treatment of moderate to severe symptomatic benign prostatic hyperplasia, alone or in combination with the alpha-blocker tamsulosin.
When Synthroid is preferred
Synthroid is approved for hypothyroidism of any cause (Hashimoto thyroiditis, post-thyroidectomy, post-radioiodine, congenital), goitre and TSH suppression after differentiated thyroid cancer.
Frequently asked questions
Is Avodart or Synthroid better? ▾
Avodart 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 Avodart to Synthroid? ▾
Switching between Avodart 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 Avodart 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 Avodart comparisons
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.