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Hair lossActive ingredient

Dutasteride

Type I and type II 5-alpha reductase inhibitor1 FDA label read

Dutasteride belongs to the same class as finasteride but blocks both type I and type II 5-alpha reductase rather than type II alone. In the United States it is approved only for benign prostatic hyperplasia. Approvals differ between countries, which is a frequent source of confusion; this page covers the US label, and that label does not mention hair loss.

Not FDA approved for hair loss

Highlights of the labels

Avodart
Enlarged prostatenot hair loss
Supply
Prescription only
Generic
8 approved applications
Boxed warning
None in these labels
Newest label read here is Avodart, effective 12 March 2025.Source documents
01

Brands and what each one is approved for

One active ingredient can hold several separate FDA approvals. They are different documents with different approved uses, and mixing them up is the most common mistake made about these medications.

AvodartWaylis Therapeutics LLCWhat its label approvesEnlarged prostateNot hair lossSupplyPrescriptionLabel version12 March 2025
02Written by us

How it works

The label describes inhibition of both isoforms of 5-alpha reductase, the enzymes that convert testosterone into dihydrotestosterone, and reports a greater reduction in circulating dihydrotestosterone than a type II inhibitor alone.

Mechanism of action, Avodart label

Dutasteride inhibits the conversion of testosterone to DHT. DHT is the androgen primarily responsible for the initial development and subsequent enlargement of the prostate gland. Testosterone is converted to DHT by the enzyme 5 alpha-reductase, which exists as 2 isoforms, type 1 and type 2.

03From the FDA label

What the FDA approved it for

The approved uses, as worded in the label.

  • AVODART is a 5 alpha-reductase inhibitor indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate to:
  • reduce the risk of the need for BPH-related surgery. AVODART in combination with the alpha-adrenergic antagonist, tamsulosin, is indicated for the treatment of symptomatic BPH in men with an enlarged prostate. Limitations of Use: AVODART is not approved for the prevention of prostate cancer.
04From the FDA label

Forms and strengths

The presentations and strengths listed in the label.

0.5-mg, opaque, dull yellow, gelatin capsules imprinted with "GX CE2" in red ink on one side. 0.5-mg soft gelatin capsules

05From the FDA label

How the label says it is taken

What the label states about administration. It is not a dosing instruction for any individual.

  • Monotherapy: 0.5 mg once daily.
  • Combination with tamsulosin: 0.5 mg once daily and tamsulosin 0.4 mg once daily.
  • Dosing considerations: Swallow whole. May take with or without food. Monotherapy The recommended dose of AVODART is 1 capsule (0.5 mg) taken once daily. Combination with Alpha-adrenergic Antagonist The recommended dose of AVODART is 1 capsule (0.5 mg) taken once daily and tamsulosin 0.4 mg taken once daily.
06From the FDA label

Most common adverse reactions

The adverse reactions the label reports as most common.

  • most common adverse reactions, reported in ≥1% of subjects treated with AVODART and more commonly than in subjects treated with placebo, are impotence, decreased libido, ejaculation disorders, and breast disorders.
  • most common adverse reactions reported in subjects receiving combination therapy (AVODART plus tamsulosin) were impotence, decreased libido, breast disorders (including breast enlargement and tenderness), ejaculation disorders, and dizziness.
  • most common adverse reaction leading to trial withdrawal was impotence (1%).
07From the FDA label

Warnings and precautions

The warnings and precautions section of the label.

  • AVODART reduces serum prostate-specific antigen (PSA) concentration by approximately 50%. However, any confirmed increase in PSA while on AVODART may signal the presence of prostate cancer and should be evaluated, even if those values are still within the normal range for untreated men.
  • AVODART may increase the risk of high-grade prostate cancer.
  • Prior to initiating treatment with AVODART, consideration should be given to other urological conditions that may cause similar symptoms.
  • Women who are pregnant or may be pregnant should not handle AVODART capsules due to potential risk to a male fetus.
  • Patients should not donate blood until 6 months after their last dose of AVODART. Effects on Prostate-Specific Antigen (PSA) and the Use of PSA in Prostate Cancer Detection In clinical trials, AVODART reduced serum PSA concentration by approximately 50% within 3 to 6 months of treatment.
08From the FDA label

Contraindications

Situations in which the label states the medication must not be used.

  • Pregnancy. Dutasteride use is contraindicated in women who are pregnant.
  • Patients with previously demonstrated, clinically significant hypersensitivity (e.g., serious skin reactions, angioedema) to AVODART or other 5 alpha-reductase inhibitors.
09From the FDA label

Drug interactions

Interactions the label singles out.

Use with caution in patients taking potent, chronic cytochrome P450 (CYP)3A4 enzyme inhibitors (e.g., ritonavir).

10From the FDA label

Pregnancy and breastfeeding

The opening of the pregnancy section of the label. The full section is longer and is in the source document.

AVODART is contraindicated for use in pregnancy because it may cause harm to the male fetus. AVODART is not indicated for use in women. AVODART is a 5 alpha‑reductase inhibitor that prevents conversion of testosterone to dihydrotestosterone (DHT), a hormone necessary for normal development of male genitalia.

11Written by us

Generic or brand

Generic dutasteride is approved and available.

The FDA label database lists 8 approved generic applications for this ingredient.

12Written by us

What affects the cost

Dutasteride is generic and inexpensive relative to brand products, but its US approval does not cover hair loss. This site sells nothing and links to no sellers.

13From CMS pricing

What pharmacies pay for it

These are acquisition costs: what pharmacies in the United States pay on average to buy the medication, published weekly by the Centers for Medicare and Medicaid Services. They are not retail prices and not what a person pays at the counter, which depends on insurance, pharmacy and discount programmes. They are useful as an objective floor and for seeing how far a brand sits above its generic.

per tablet, capsule or penGeneric$0.172 (range $0.166 to $0.178, 250 listings)

Median of 250 listings. Effective dates 2025-12-17 to 2026-07-22, file dated 2026-07-29.

14

Compared with other medications

What the labels do not do is compare one medication against another. These pages put two of them side by side.

15Written by us

Common questions

Is dutasteride approved for hair loss in the United States?
No. The US label covers benign prostatic hyperplasia, and that is the document this page is built from. Approvals differ between countries, so a claim you read elsewhere may be describing a different regulator. We only report what the linked US label says.
What is Avodart?
Avodart is the brand name under which dutasteride is sold in the United States, and it is the label this page is built from. That label indicates it for symptomatic benign prostatic hyperplasia in men with an enlarged prostate, on its own or in combination with tamsulosin, and states that it is not approved for the prevention of prostate cancer.
Is Avodart used by women?
The US label covers treatment in men. It contraindicates use in women who are pregnant, and it instructs that women who are pregnant or may be pregnant should not handle the capsules, because of the potential risk to a male fetus. The label describes no approved use in women.
How does it differ from finasteride?
Finasteride inhibits type II 5-alpha reductase. Dutasteride inhibits both type I and type II. The comparison page sets out what each label says side by side.
16

Other medications under hair loss

Whether each one carries an FDA approval for this use is marked on its page and in this list.

17

Sources

Every fact above comes from one of these documents. The date is the effective date of the label version this page was built from.

Each stripe is one section of the label, each division in a stripe one entry in that section.

Page last updated 18 August 2026

Compiled by the HealthyStudy editorial team from FDA source documents. No medical reviewer is credited on this page, because none reviewed it.