medicationPrescription only (US)FDA-approved for benign prostatic hyperplasia; hair-loss use is off-label in the USContraindicated in pregnancy
DutasterideBenefits, Dosage & Interactions
Also known as: Avodart
Dutasteride is a medication primarily prescribed for the management of benign prostatic hyperplasia (BPH), also known as an enlarged prostate, and for male pattern hair loss (androgenetic alopecia). It belongs to a class of drugs called 5-alpha-reductase inhibitors. The reported plasma half-life is about 1200 hours, which shapes dosing frequency.
How much Dutasteride do people take?
0.5 mg/day is the amount used for benign prostatic hyperplasia and in the hair-loss comparisons. Route reported: Oral. Frequency reported: Once daily. These are amounts documented in the cited studies and labels for Dutasteride — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
See the full reported protocol and its sourcesResearched by DoseRoutine Research TeamReviewed for accuracy by Nicholas Alexander, RSE, SO, PMPLast updated Educational reference only — not medical advice. Always confirm dosing and safety decisions with a licensed clinician.
Evidence: Strong — 1 human randomized trial and regulatory approval on file.
Evidence strengthStrong · 4/4
PreclinicalStrong human evidence
1 human randomized trial and regulatory approval on file.
How does dutasteride affect prostate symptoms?
Dutasteride inhibits 5-alpha reductase, reducing conversion of testosterone to DHT. It is used for benign prostate enlargement, not as immediate relief for an inability to urinate, which needs urgent assessment.
Source: MedlinePlus: Dutasteride
Browse compound evidence cardsPlasma half-life
~1200 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 Dutasteride in the cited sources. Published ranges are not dosing advice.
References & evidence
Documents the Dutasteride entry is written from. Each number matches an inline marker above.
- [1]Efficacy and safety of oral finasteride versus dutasteride in moderate-to-severe androgenetic alopecia in malesPoostiyan N, et al. · Journal of Dermatological Treatment · 2026 · Peer-reviewed · PMID 42466626
- [2]Impact of 5-alpha reductase inhibitors on male reproductive health: A review of finasteride and dutasterideQuintero T, et al. · Reproductive Toxicology · 2026 · Peer-reviewed · PMID 42069234
References & Evidence
Sources on this page that document Dutasteride dosing, timing and safety.
- [1]National Center for Biotechnology Information View source
- [2]U.S. National Library of Medicine View source
Educational information only — not medical advice. Dose ranges vary by person, indication and prescriber.
What is Dutasteride?Sources for this section: Jumps to this entry in the sources and references list at the end of the page.
Dutasteride is a medication primarily prescribed for the management of benign prostatic hyperplasia (BPH), also known as an enlarged prostate, and for male pattern hair loss (androgenetic alopecia). It belongs to a class of drugs called 5-alpha-reductase inhibitors. Its action involves reducing the levels of dihydrotestosterone (DHT), a potent androgen hormone that plays a key role in the development of BPH and hair loss. Dutasteride is available in oral capsule form and is often marketed under the brand name Avodart. It is typically used long-term due to its mechanism of action and the chronic nature of the conditions it treats. The dose is user-directed and must be set by a licensed clinician.
What does the research say about Dutasteride?
Tap a section to expand.
Dutasteride functions as a dual inhibitor of the enzyme 5-alpha-reductase. This enzyme exists in two main isoforms, type 1 and type 2, both of which are responsible for converting testosterone into dihydrotestosterone (DHT). DHT is a more potent androgen than testosterone and is implicated in various physiological processes and pathological conditions. In the prostate, DHT stimulates the growth of prostatic cells, leading to BPH. In hair follicles, it contributes to the miniaturization of hair follicles, leading to male pattern hair loss.
Dutasteride inhibits both 5-alpha-reductase type 1 and type 2, whereas finasteride, another drug in the same class, primarily inhibits type 2. By inhibiting these enzymes, dutasteride significantly reduces serum and intraprostatic DHT levels. This reduction in DHT leads to a shrinkage of the enlarged prostate gland over time, improving urinary flow and reducing BPH-related symptoms. For male pattern hair loss, the reduction in DHT helps to reverse the miniaturization process, promoting hair growth and slowing down further hair loss.
Source for this section: Sources for How does Dutasteride work?: Jumps to this entry in the sources and references list at the end of the page.
Dutasteride offers several key benefits for individuals with specific conditions:
* **Benign Prostatic Hyperplasia (BPH) Treatment:** For men with BPH, dutasteride can significantly reduce the size of the prostate, improve urinary flow, and alleviate bothersome urinary symptoms such as frequent urination, urgency, weak stream, and incomplete bladder emptying. It has also been shown to reduce the risk of acute urinary retention and the need for BPH-related surgery (FDA label).
* **Male Pattern Hair Loss (Androgenetic Alopecia):** In men experiencing male pattern hair loss, dutasteride can help to increase hair count, improve hair thickness, and slow down the progression of hair loss. It is considered effective in areas such as the crown and frontal scalp. (PubChem)
It is important to note that the full benefits of dutasteride, particularly for BPH, may not be apparent for several months of consistent use. For hair loss, visible improvements may also take several months.
Clinical studies have robustly demonstrated the efficacy of dutasteride for both BPH and male pattern hair loss.
For BPH, a review published in the *Cochrane Database of Systematic Reviews* analyzed multiple trials, concluding that 5-alpha reductase inhibitors like dutasteride are effective in improving urinary symptoms, reducing prostate volume, and preventing BPH-related complications. The FDA label for dutasteride (Avodart) specifically outlines studies where dutasteride led to statistically significant reductions in prostate volume and improvements in symptom scores compared to placebo over a period of 6 months to 2 years.
Regarding male pattern hair loss, a meta-analysis published in the *Journal of the American Academy of Dermatology* compared dutasteride with finasteride and placebo, finding dutasteride to be more effective than finasteride and placebo in increasing total hair count and improving subjective and objective assessments of hair growth. Studies cited by DrugBank also support dutasteride's efficacy in increasing hair count in men with androgenetic alopecia, often showing superior results to finasteride over similar treatment durations. The mechanism of dual inhibition of 5-alpha-reductase enzymes by dutasteride is hypothesized to contribute to its enhanced efficacy in reducing DHT levels compared to finasteride.
Common side effects associated with dutasteride primarily relate to its effects on hormone levels:
* Decreased libido (sex drive)
* Ejaculation disorders (e.g., decreased ejaculate volume)
* Erectile dysfunction (difficulty getting or maintaining an erection)
* Breast tenderness and enlargement (gynecomastia)
* Allergic reactions, including rash, itching, hives, and localized swelling (e.g., face, lips, throat)
* Mood changes, including depression
* Headache
Less common but serious side effects include:
* Male breast cancer (reported rarely; the relationship with dutasteride is not definitively established but requires monitoring. The FDA label advises healthcare providers to instruct patients to report any breast changes.)
* High-grade prostate cancer (some studies have indicated an increased risk of high-grade prostate cancer with 5-alpha-reductase inhibitors, though the overall survival benefit for low-grade prostate cancer might be present, and the clinical significance is still under investigation. Patients should discuss this with their clinician.)
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for What are the side effects of Dutasteride?: Jumps to this entry in the sources and references list at the end of the page.
Dutasteride carries several important warnings:
* **Risk of High-Grade Prostate Cancer:** While dutasteride reduces the overall risk of prostate cancer, there is an observed increased risk of developing high-grade prostate cancer in some men taking 5-alpha-reductase inhibitors. Patients should be regularly screened for prostate cancer, and any symptoms or concerns should be discussed with a clinician (FDA label).
* **Effect on Prostate-Specific Antigen (PSA):** Dutasteride reduces serum PSA levels by approximately 50% after 6 months of use. This reduction must be considered when interpreting PSA values for prostate cancer screening. A clinician should establish a new baseline PSA and adjust subsequent readings accordingly (NIH ODS).
* **Reproductive Effects:** Dutasteride can affect sperm characteristics, including decreased sperm count, semen volume, and sperm motility. The long-term effects on male fertility are not fully established but have been reported in some men (EMA SmPC).
* **Exposure to Women:** Due to its teratogenic potential, women who are pregnant or may become pregnant should not handle dutasteride capsules, as the active ingredient can be absorbed through the skin and may cause abnormalities in a male fetus (NIH ODS).
* **Blood Donation:** Men taking dutasteride should not donate blood for at least 6 months after their last dose to prevent exposure of dutasteride to pregnant women through blood products (FDA label).
* **Mood Disorders:** Dutasteride may cause mood alterations, including depression. Patients and their families should be advised to monitor for psychiatric symptoms and seek medical advice if these occur (EMA SmPC).
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for Who should avoid Dutasteride?: Jumps to this entry in the sources and references list at the end of the page.
Dutasteride is contraindicated in the following situations:
* **Hypersensitivity:** Individuals with a known hypersensitivity to dutasteride, other 5-alpha-reductase inhibitors (e.g., finasteride), or any component of the product formulation should not use dutasteride.
* **Pregnancy and Women of Childbearing Potential:** Dutasteride is contraindicated for use in women, particularly those who are pregnant or who may become pregnant. It can cause serious birth defects in a male fetus by inhibiting the development of external genitalia (FDA label).
* **Pediatric Use:** Dutasteride is not indicated for use in children.
* **Severe Hepatic Impairment:** While not an absolute contraindication, caution is advised, and the use of dutasteride may be contraindicated in individuals with severe liver impairment, as the drug is extensively metabolized by the liver (EMA SmPC).
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for When should Dutasteride not be taken?: Jumps to this entry in the sources and references list at the end of the page.
While dutasteride does not have an extensive list of absolute contraindications with other medications, certain interactions should be noted due to its metabolic pathway:
* **CYP3A4 Inhibitors:** Dutasteride is metabolized by the cytochrome P450 3A4 (CYP3A4) enzyme. Co-administration with strong CYP3A4 inhibitors (e.g., ritonavir, indinavir, ketoconazole, itraconazole, telithromycin, nefazodone) may significantly increase dutasteride plasma concentrations, potentially leading to increased side effects. Dose adjustments or closer monitoring may be necessary (DrugBank).
* **Alpha-Blockers (e.g., Tamsulosin):** Dutasteride is often used concomitantly with alpha-blockers to manage BPH symptoms. Clinical studies assessing combination therapy have shown benefits, but clinicians should be aware of the individual side effect profiles of both drug classes (FDA label).
Always inform your treating clinician about all medications, supplements, and herbal products you are taking to ensure safe co-administration.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for What should you not mix with Dutasteride?: Jumps to this entry in the sources and references list at the end of the page.
Dutasteride can typically be taken at any time of day, with or without food. Consistency in dosing time each day is often recommended to maintain stable drug levels in the body. However, the specific dose and timing are user-directed and must be set by a licensed clinician. Due to its long half-life (approximately 5 weeks), steady-state concentrations are reached after about 6 months of daily dosing (FDA label). This long half-life means that its effects persist for an extended period even after discontinuation.
Source for this section: Sources for When should you take Dutasteride?: Jumps to this entry in the sources and references list at the end of the page.
Put it into practice
Reading about Dutasteride is the first step — DoseRoutine helps you act on it. These free tools turn what you just learned into a routine.
What interacts with Dutasteride?
| 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 for this interaction: Jumps to this entry in the sources and references list at the end of the page. | 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 for this interaction: Jumps to this entry in the sources and references list at the end of the page. | 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 for this interaction: Jumps to this entry in the sources and references list at the end of the page. | Discuss goals with prescribing clinician; monitor sexual function. |
Frequently asked questions about Dutasteride
For BPH, significant improvements in symptoms and prostate size may take 3 to 6 months of consistent use, with full benefits potentially taking up to 12 months. For male pattern hair loss, visible improvements can take 3 to 6 months, and continued use is generally necessary to maintain results.
Dutasteride does not cure BPH or hair loss. For BPH, it helps manage symptoms and reduce prostate size. For hair loss, it helps slow progression and promote new growth but does not restore all lost hair. Benefits typically cease if the medication is discontinued, and the conditions may progress again.
Yes, dutasteride significantly reduces serum PSA levels, typically by about 50% after 6 months of use. It is crucial to inform your clinician that you are taking dutasteride if you undergo a PSA test for prostate cancer screening, as the results will need to be interpreted differently. Your clinician will establish a new baseline PSA for you.
No specific dietary restrictions are typically required with dutasteride. It can be taken with or without food. However, maintaining a healthy lifestyle is generally recommended, especially for conditions like BPH.
No, dutasteride is contraindicated for use in women, particularly those who are pregnant or who may become pregnant. Exposure to dutasteride can cause serious birth defects in a male fetus. Women should avoid handling dutasteride capsules, or wear gloves if handling is unavoidable.
Interaction risk for Dutasteride comes from the rest of the stack: other medications, prescription medicines, hormone therapy and peptides. With a reported plasma half-life near 1200 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 Dutasteride with no sign-up.
The reported plasma half-life is about 1200 hours, which is what drives how often it is redosed. Published ranges differ between studies and formulations — the dose to use is the one on your label or from your clinician.
There is no single answer for Dutasteride 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 Dutasteride 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 long plasma half-life of about 1200 hours means Dutasteride is commonly dosed every few days or weekly rather than daily. 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
With a plasma half-life near 1200 hours, a single missed dose of Dutasteride usually has a smaller effect on overall exposure than an irregular pattern of missed doses does. 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 Dutasteride 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.
Dutasteride inhibits 5-alpha reductase, reducing conversion of testosterone to DHT. It is used for benign prostate enlargement, not as immediate relief for an inability to urinate, which needs urgent assessment.
Capsules should be swallowed whole, not opened or crushed. Leaking capsules can expose others to the medicine; people who are or may be pregnant should not handle them because of fetal risk.
0.5 mg/day is the amount used for benign prostatic hyperplasia and in the hair-loss comparisons. Route reported: Oral. Frequency reported: Once daily. These are amounts documented in the cited studies and labels for Dutasteride — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
Which studies looked at Dutasteride?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.Comparison of oral minoxidil, finasteride, and dutasteride for treating androgenetic alopecia(opens PubMed in a new tab)J Dermatolog Treat · 2022 · PMID 35920739 · https://pubmed.ncbi.nlm.nih.gov/35920739/
- 2.Topical dutasteride for androgenic alopecia: current state and prospects(opens PubMed in a new tab)Ther Deliv · 2025 · PMID 39641480 · https://pubmed.ncbi.nlm.nih.gov/39641480/
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- PubChem CID 11679580(opens in a new tab)National Center for Biotechnology Information · pubchem.ncbi.nlm.nih.gov/compound/11679580
- MedlinePlus(opens in a new tab)U.S. National Library of Medicine · medlineplus.gov/druginfo/meds/a603001.html
Verify at
Publisher search links for Dutasteride. These are places to check the information — they are not citations, so they are not numbered.
- 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
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- European Medicines Agency(publisher search, opens in a new tab)European Medicines Agency · publisher search
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- Wikipedia entry(publisher search, opens in a new tab)Wikipedia · 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 Dutasteride?
Plain-text summary, safe to quote verbatim:
Dutasteride is a medication primarily prescribed for the management of benign prostatic hyperplasia (BPH), also known as an enlarged prostate, and for male pattern hair loss (androgenetic alopecia). It belongs to a class of drugs called 5-alpha-reductase inhibitors. The reported plasma half-life is about 1200 hours, which shapes dosing frequency.
Source: DoseRoutine — https://doseroutine.com/library/dutasteride
Dutasteride cheat sheet
DoseRoutine cheat sheet · Medication
Dutasteride
Dutasteride is a medication primarily prescribed for the management of benign prostatic hyperplasia (BPH), also known as an enlarged prostate, and for male pattern hair loss (androgenetic alopecia). It belongs to a class of drugs called 5-alpha-reductase inhibitors.
Evidence
Strong
1 human randomized trial and regulatory approval on file.
Studied range
0.5 mg/day is the amount used for benign prostatic hyperplasia and in the hair-loss comparisons
Route
Oral
Frequency studied
Once daily
Half-life
~1200 h
Storage
Room temperature; soft capsules should not be handled if leaking
Prescription only (US)FDA-approved for benign prostatic hyperplasia; hair-loss use is off-label in the USContraindicated in pregnancy
Studied ranges, not dosing advice. Not medical advice — talk to a clinician. doseroutine.com/library/dutasteride
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Dutasteride — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/dutasteride
What compounds are similar to Dutasteride?
Others in the medication category or studied for the same goals.