### Contents of Finasteride Encyclopedia #### **Paragraph 1: Overview and core content**

Finasteride is a 5α-reductase inhibitor mainly used to treatMale hair loss (androgenetic alopecia)andBenign prostatic hyperplasia (BPH). Its mechanism of action is by inhibiting the conversion of testosterone into dihydrotestosterone (DHT), thereby reducing hair follicle atrophy and prostate hyperplasia. Mainly divided into1mg (hair loss treatment)and5mg (prostate treatment)There are two dosages, and they must be used according to the doctor's advice. Common brands include Merck’sPropeciaandProscar, there are also generic drug production in China. Be aware of possible side effects (such as sexual dysfunction), but their incidence is low. The following is the detailed content.

#### **Second Paragraph: Mechanism of Action and Indications**

Finasteride selectively inhibitsType II 5α-reductase, blocks the production of DHT. DHT is a key factor leading to hair follicle miniaturization and prostate hyperplasia, so this drug is effective formale pattern baldness(sparse forehead and crown) andenlarged prostateAll have significant curative effects. Clinical data show that continuous administration of 1 mg/d of finasteride can reduce83%of hair loss patients can stop hair loss,66%Hair regrowth occurs (data source: MSD clinical trials). The 5 mg dose for the treatment of prostatic hyperplasia must be used strictly according to symptoms.

#### **Paragraph 3: Usage, Dosage and Precautions**

finasterideThe dosage for hair loss treatment is 1mg/day, need to continue3-6 monthsEffective, the effects may be reversed after stopping the drug. Patients with prostatic hyperplasia need to take5mg/day, but not for use on women or children. Common side effects includeLoss of libido, erectile dysfunction(Incidence rate <2%), most of them recover after stopping the drug. Contraindications include pregnant women (may cause fetal malformations) and those allergic to ingredients. Prostate-specific antigen (PSA) levels need to be monitored regularly during medication.

#### **Paragraph 4: Market products and manufacturers**

The origin of finasterideMerck Sharp & DohmeProduction, trade namePropecia (1mg)andProscar (5mg). Domestic generic drug manufacturers includeZhejiang Xianju Pharmaceutical,Yangzijiang Pharmaceuticaletc., product names such as"Qiyue"(1mg). In terms of price, the original drug is about150-200 yuan/box (28 pieces), generic drugs are cheaper. Here are some product comparisons:

Product name	dose	Manufacturer	reference price
Propecia	1mg	Merck	180 yuan/box
Qiyue	1mg	Zhejiang Xianju	80 yuan/box
Proscar	5mg	Merck	120 yuan/box

#### **Paragraph 5: Summary and scientific consensus**

Finasteride isFDAandChina Food and Drug AdministrationApproved effective drugs, but efficacy needs to be weighed against potential risks. The International Hair Loss Society (IHS) recommends combiningMinoxidilUse to enhance the effect. Patients should avoid self-adjustment of dosage and consult a professional physician. Research shows that its efficacy and safety are controllable in most people (Quote:New England Journal of Medicine). More targeted therapies may become available in the future, but currently finasteride remains the first-line option for hair loss and prostate treatment.

**Citation sources**: 1. Merck's drug insert (Propecia/Proscar) 2. China Food and Drug Administration drug information database 3. "New England Journal of Medicine": Finasteride clinical study (1998)