medicationPrescription only (US)Finasteride 1 mg is FDA-approved (Propecia and generics) specifically for male pattern hair loss; the 5 mg strength is a separate approval for benign prostatic hyperplasia
Finasteride 1mgBenefits, Dosage & Interactions
Also known as: Propecia
Finasteride 1mg, commonly known by the brand name Propecia, is a medication primarily used for the treatment of male pattern hair loss (androgenetic alopecia) in men. The reported plasma half-life is about 4.8 hours, which shapes dosing frequency. Dose, response, and interaction risk vary by individual, so use should be reviewed with a clinician.
Researched by DoseRoutine R&D TeamReviewed for accuracy by Nicholas Alexander, RSELast updated
Evidence: Strong — 2 human randomized trials and regulatory approval on file.
Evidence strengthStrong · 4/4
PreclinicalStrong human evidence
2 human randomized trials and regulatory approval on file.
Plasma half-life
4.8–6 h
Default unit
mg
What published protocols report
Ranges documented in the literature, shown for reference. DoseRoutine does not recommend an amount — your prescriber or the product label sets the dose.
Reported for Finasteride 1mg in the cited sources. Published ranges are not dosing advice.
References & evidence
Documents the Finasteride 1mg entry is written from. Each number matches an inline marker above.
- [1]Finasteride in the treatment of men with androgenetic alopecia. Finasteride Male Pattern Hair Loss Study GroupKaufman KD, Olsen EA, Whiting D, Savin R, DeVillez R, Bergfeld W, Price VH, Van Neste D, Roberts JL, Hordinsky M, Shapiro J, Binkowitz B, Gormley GJ · Journal of the American Academy of Dermatology · 1998 · Peer-reviewed · PMID 9777765
- [2]Setipiprant for Androgenetic Alopecia in Males: Results from a Randomized, Double-Blind, Placebo-Controlled Phase 2a TrialDuBois J, Bruce S, Stewart D, Kempers S, Harutunian C, Boodhoo T, Weitzenfeld A, Chang-Lin JE · Clinical, Cosmetic and Investigational Dermatology · 2021 · Peer-reviewed · PMID 34703265
How to track Finasteride 1mg doses
Tracking Finasteride 1mg well takes four fields and a habit. Here is what to record so the log is still useful in three months.
- 1
Add the dose and unit
Log Finasteride 1mg with its dose in mg so totals stay comparable over time — including days when you split the dose or skip it.
- 2
Set the time of day and food rule
Pick the time you actually take it. Reminders fire at that time and can export to your calendar.
- 3
Check it against the rest of the stack
Run Finasteride 1mg through the interaction checker against everything else in the routine — supplements, peptides, hormones and prescriptions — before it becomes a daily habit.
- 4
Log adherence, not intentions
Mark each dose taken, skipped or delayed as it happens. Weeks of honest logs are what make an adherence rate or a trend line meaningful; retrospective guessing is not.
- 5
Review against outcomes
With a reported half-life around 4.8 h, effects and timing shifts show up over days rather than instantly. Review Finasteride 1mg alongside your logged metrics and any relevant blood work every few weeks before changing the dose.
What to log each time
- Dose in mg
- Time of day
- Taken / skipped / delayed
- Any side effects or notable changes
References & Evidence
Sources on this page that document Finasteride 1mg dosing, timing and safety.
- [1]National Center for Biotechnology Information View source
Educational information only — not medical advice. Dose ranges vary by person, indication and prescriber.
What is Finasteride 1mg?Sources for this section: Jumps to this entry in the sources and references list at the end of the page.
Finasteride 1mg, commonly known by the brand name Propecia, is a medication primarily used for the treatment of male pattern hair loss (androgenetic alopecia) in men. It works by reducing the levels of dihydrotestosterone (DHT), a hormone that plays a key role in the miniaturization of hair follicles and subsequent hair loss. Finasteride is classified as a 5-alpha reductase inhibitor. It is taken orally, typically once daily. While it can effectively slow down hair loss and even promote new hair growth in some men, its effects are generally sustained only as long as the medication is taken. Upon discontinuation, hair loss often resumes within several months.
What does the research say about Finasteride 1mg?
Tap a section to expand.
Finasteride 1mg functions as a competitive and specific inhibitor of type II 5-alpha reductase, an intracellular enzyme responsible for converting testosterone to dihydrotestosterone (DHT). DHT is a potent androgen hormone. In men genetically predisposed to male pattern hair loss, DHT contributes significantly to the progressive miniaturization of hair follicles on the scalp, leading to thinner, shorter hairs and eventual hair loss. By inhibiting 5-alpha reductase, finasteride reduces scalp and serum DHT concentrations. This reduction in DHT can reverse the hair loss process, slow down further hair loss, and stimulate regrowth of hair in some individuals. The decrease in DHT levels is dose-dependent, with finasteride 1mg specifically targeting the levels needed for androgenetic alopecia treatment. (FDA label for Propecia)
Source for this section: Sources for How does Finasteride 1mg work?: Jumps to this entry in the sources and references list at the end of the page.
The primary benefit of Finasteride 1mg is the treatment of male pattern hair loss (androgenetic alopecia). Clinical studies have consistently shown that finasteride can:
* **Reduce further hair loss**: It helps to stop the progression of hair thinning and balding.
* **Promote hair regrowth**: Many men experience new hair growth, particularly in the crown area.
* **Improve hair thickness and scalp coverage**: Over time, treated hair may become thicker and cover the scalp more effectively.
* **Maintain existing hair**: It helps to preserve the hair that is still present.
These benefits are typically observed after several months of consistent use (often 3-6 months), and maximum effects may take 12 months or longer to become apparent. The efficacy of finasteride is maintained only with continued use; discontinuation usually leads to the resumption of hair loss within 6-12 months. (Mayo Clinic)
Multiple clinical trials and long-term observational studies support the efficacy of finasteride 1mg in treating male pattern hair loss. A randomized, placebo-controlled, double-blind study observed men with androgenetic alopecia over a period of 24 months. Results indicated that finasteride-treated subjects experienced significant increases in hair count compared to placebo, with improvements in global photographic assessment and patient self-assessment scores. Another study, extended to 5 years, demonstrated that finasteride maintained and even improved hair count and appearance in a majority of men. The FDA approved finasteride 1mg for male pattern hair loss based on robust evidence from these and other trials showing its ability to decrease scalp DHT levels and consequently improve hair growth parameters. (FDA label for Propecia, DrugBank)
Possible side effects of Finasteride 1mg may include:
* Decreased libido (sex drive)
* Erectile dysfunction
* Ejaculation disorders (e.g., decreased ejaculate volume)
* Breast tenderness and enlargement (gynecomastia)
* Rash
* Depression, including suicidal ideation
* Anxiety
* Testicular pain
* Rarely, male breast cancer has been reported (however, a causal relationship has not been established and further research is ongoing).
* Post-finasteride syndrome (PFS) is a controversial and poorly understood condition reported by some individuals, characterized by persistent sexual, neurological, and physical side effects after discontinuing the drug. The medical community continues to research and debate the existence and mechanisms of PFS. (NIH ODS, FDA label for Propecia)
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Finasteride 1mg should be used with caution in certain situations. It is not indicated for use in women or children. Pregnant women should not handle crushed or broken Finasteride tablets, as finasteride can be absorbed through the skin and may cause abnormalities of the external genitalia in a male fetus. There have been reports of high-grade prostate cancer in men treated with finasteride for benign prostatic hyperplasia (BPH) at higher doses (5mg), although the effect of the 1mg dose on prostate cancer risk is less clear. Finasteride can also affect Prostate Specific Antigen (PSA) test results, which are used to screen for prostate cancer; clinicians should be informed if a patient is taking finasteride as it can lower PSA levels, potentially masking prostate cancer. Patients should be monitored for changes in mood, including depression and suicidal thoughts, and should seek medical attention if such symptoms occur. (FDA label for Propecia, MedlinePlus)
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Finasteride 1mg is contraindicated in:
* **Women**: Especially those who are or may potentially be pregnant, due to the risk of fetal abnormalities.
* **Children**: Its safety and efficacy have not been established in pediatric patients.
* **Individuals with hypersensitivity** to finasteride or any component of the tablet. (FDA label for Propecia)
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
There are no significant drug-drug interactions specifically highlighted for Finasteride 1mg that would necessitate avoiding its combination with particular substances. However, as with all medications, it is important to inform your healthcare provider about all prescription drugs, over-the-counter medications, and herbal supplements you are taking. Finasteride is metabolized by the cytochrome P450 enzyme system, specifically CYP3A4, but significant interaction with other drugs metabolized by this pathway is not anticipated due to its low binding affinity. (FDA label for Propecia)
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Finasteride 1mg is typically taken orally once a day. The specific timing within the day (morning, evening) does not generally affect its efficacy, so it can be taken at any time that is convenient for the user to ensure consistent daily administration. It can be taken with or without food. Consistent daily use is crucial for achieving and maintaining therapeutic effects. The onset of visible results for hair growth and reduced hair loss typically takes several months, and full effects may not be apparent for 12 months or more. If a dose is missed, it should not be doubled at the next scheduled time; simply resume the regular dosing schedule. (FDA label for Propecia, MedlinePlus)
Source for this section: Sources for When should you take Finasteride 1mg?: Jumps to this entry in the sources and references list at the end of the page.
What interacts with Finasteride 1mg?
| Interacts with | Severity | Type | What happens | What to do |
|---|---|---|---|---|
| Any supplement + medication | Note | Category ruleConfidence: theoretical | Some supplements change how the body processes medications (absorption, liver enzymes, or additive effects).Source pending | Specific pairs are checked against a licensed drug database and shown with their own severity. Always confirm with your provider or pharmacist. |
| Any vitamin + medication | Note | Category ruleConfidence: theoretical | Certain vitamins interact with specific medications (e.g., vitamin K with blood thinners).Source pending | Specific pairs are checked against a licensed source; confirm with your provider. |
| Testosterone Cypionate | Caution | Compound pairConfidence: theoretical | 5-alpha-reductase inhibitors block DHT conversion; can affect libido and prostate response on TRT.Source pending | Discuss goals with prescribing clinician; monitor sexual function. |
Frequently asked questions about Finasteride 1mg
Finasteride 1mg is a medication. It is also known as Propecia. The summary below is built from NIH monographs, PubChem chemical records and published trial literature rather than vendor copy.
Finasteride 1mg is commonly discussed in the context of the goals discussed on its profile page. Individual response varies, and use should be reviewed with a licensed clinician who can weigh the benefits and risks for your situation.
For Finasteride 1mg, it is typically taken null and its approximate half-life is 4.8 hours, which influences dosing frequency. Always follow the specific dose your clinician or the product label prescribes.
Finasteride 1mg carries potential side effects and drug interactions, documented in NIH, Mayo Clinic, and FDA label sources. Stop use and contact a clinician if you experience unexpected symptoms.
Interaction risk for Finasteride 1mg comes from the rest of the stack: other medications, prescription medicines, hormone therapy and peptides. With a reported plasma half-life near 4.8 hours, separating doses can change the picture as much as removing one. Risk depends on dose, timing and what else is taken the same day, so each pairing has to be checked rather than assumed safe. The free checker at https://doseroutine.com/interaction-checker covers Finasteride 1mg with no sign-up.
There is no single answer for Finasteride 1mg plus TRT. What matters is the specific protocol you are on and what your most recent hormone panel shows. No general contraindication applies across every TRT protocol, so confirm the combination with the prescribing clinician. See the free TRT interaction reference: https://doseroutine.com/trt-supplement-interactions
Pairing Finasteride 1mg with peptides has to be assessed one peptide at a time, because GLP-1 agonists, secretagogues, healing peptides and melanocortins do not share an interaction profile. Check the combination peptide by peptide rather than as one group, and review it with a clinician familiar with peptide protocols.
A short plasma half-life of roughly 4.8 hours is why protocols often split Finasteride 1mg across the day rather than using a single dose. Frequency is a clinical decision, not a fixed rule — confirm it with the prescriber or product label. Comparison of apps that keep a schedule like this: https://doseroutine.com/best-dose-tracking-apps
Because Finasteride 1mg clears quickly (plasma half-life around 4.8 hours), a missed dose leaves a real gap in exposure rather than being buffered by what is still in your system. Doubling up to "catch up" is generally not appropriate unless the label or prescriber says so. Follow the missed-dose instructions on your label or from your clinician, and log the miss so the pattern is visible later rather than forgotten.
For Finasteride 1mg the useful record is the dose, the time it was actually taken, and what else was taken in the same window. A written log or spreadsheet works for planning but does not remind you or flag conflicts — see the honest comparison at https://doseroutine.com/vs/spreadsheet and the wider roundup at https://doseroutine.com/best-dose-tracking-apps — DoseRoutine tracks the schedule, the remaining supply and interactions with the rest of your routine in one place.
Which studies looked at Finasteride 1mg?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.Finasteride-associated male infertility(opens PubMed in a new tab)Rev Hosp Clin Fac Med Sao Paulo · 2004 · PMID 15361986 · https://pubmed.ncbi.nlm.nih.gov/15361986/
- 2.Isolated depressive disorders and suicidality with finasteride use for androgenetic alopecia: A call for enhanced vigilance(opens PubMed in a new tab)Therapie · 2025 · PMID 41027755 · https://pubmed.ncbi.nlm.nih.gov/41027755/
- 3.Finasteride associated melasma in a Caucasian male(opens PubMed in a new tab)J Drugs Dermatol · 2014 · PMID 24719069 · https://pubmed.ncbi.nlm.nih.gov/24719069/
- 4.Analysis of the finasteride treatment and its withdrawal in the rat hypothalamus and hippocampus at whole-transcriptome level(opens PubMed in a new tab)J Endocrinol Invest · 2024 · PMID 38493246 · https://pubmed.ncbi.nlm.nih.gov/38493246/
- 5.Viable terminal scalp hair follicles constitute a necessary and sufficient biological end-organ that conditions clinical efficacy of finasteride in males with male pattern hair loss without implying reversal of miniaturized follicles(opens PubMed in a new tab)Skin Res Technol · 2019 · PMID 31206839 · https://pubmed.ncbi.nlm.nih.gov/31206839/
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- PubChem CID 57363(opens in a new tab)National Center for Biotechnology Information · pubchem.ncbi.nlm.nih.gov/compound/57363
Verify at
Publisher search links for Finasteride 1mg. These are places to check the information — they are not citations, so they are not numbered.
- MedlinePlus(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- FDA-approved labeling (DailyMed)(publisher search, opens in a new tab)U.S. Food and Drug Administration · publisher search
- NIH Office of Dietary Supplements(publisher search, opens in a new tab)National Institutes of Health · publisher search
- Mayo Clinic(publisher search, opens in a new tab)Mayo Clinic · publisher search
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on Finasteride 1mg?
Plain-text summary, safe to quote verbatim:
Finasteride 1mg, commonly known by the brand name Propecia, is a medication primarily used for the treatment of male pattern hair loss (androgenetic alopecia) in men. The reported plasma half-life is about 4.8 hours, which shapes dosing frequency. Dose, response, and interaction risk vary by individual, so use should be reviewed with a clinician.
Source: DoseRoutine — https://doseroutine.com/library/finasteride-1mg
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Finasteride 1mg — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/finasteride-1mg
What compounds are similar to Finasteride 1mg?
Others in the medication category or studied for the same goals.