Research library
Finasteride, explained
12 guides, organized by the question you are trying to answer.
Research Guides
Finasteride and fertility: what the label and studies say about semen and sperm
What the Propecia label and three studies report about semen, sperm counts and reversibility, with the dose used in each.
What the Finasteride 1 mg prescribing information says about use in men
A plain summary of what the Propecia (finasteride 1 mg) label says about who it is indicated for, how it is taken and who it is not for.
PSA tests and prostate cancer screening while taking Finasteride
What the label and trials report about PSA on finasteride, and what the label and the 5 mg Prostate Cancer Prevention Trial say about prostate cancer.
What the Finasteride trials measured: label studies, long-term data and reviews
What the label's 12-month studies, long-term data, published trials and reviews measured, plus one 2023 review that reported a different result.
Who Finasteride 1 mg is not for: women, children and pregnancy exposure
What the Propecia label and the FDA say about women, pregnancy, children, handling and semen exposure.
How Finasteride works: the enzyme, DHT and what was measured
What the Propecia label and a 1999 study abstract say about finasteride, the Type II 5α-reductase enzyme and DHT, with each number tied to its source.
How long Finasteride takes to show results and what sources say about stopping
What the Propecia label reports about timing, the 12-month and 5-year study measures, and what it says happens after treatment is withdrawn.
Mood and Finasteride: what the sources say about depression and suicidal ideation
The label listings, cohort studies, reviews and spontaneous-report analyses on depression and suicidal ideation, and why none show cause and effect.
Other treatments for male pattern hair loss: what the sources say
What labels, reviews, trials and a Canadian consensus say about minoxidil, dutasteride, topical finasteride and low-level laser therapy.
Sexual side effects of Finasteride: what the label, trials and databases report
What the label, trials, reviews, a claims database and reports say about sexual side effects, with rates, study length and comparison groups.
What male pattern hair loss is and what drives it
What MedlinePlus and review sources say about male pattern hair loss: the usual pattern, androgens and genes, and what else can cause hair loss.
When hair loss is not pattern loss: other causes and how they are found
Other causes of hair loss that MedlinePlus lists, and how review abstracts say clinicians tell them apart from pattern loss.
