Dutasteride

Dutasteride is a prescription-only medicine licensed in the USA and UK for benign prostatic hyperplasia, but it may be prescribed off-label by a clinician for male-pattern hair loss (androgenetic alopecia), where appropriate. Hair loss is a common condition that can affect men of any age. Around 50% of men over 50 are affected, though it can start earlier. The condition can have a significant psychological impact, with one study suggesting that hair loss contributed to “depleted confidence and wellbeing” in over half (57%) of respondents. A 2022 review of 13 studies also suggested that men would benefit from psychological support in addition to seeking treatment for the condition.

The medication was originally licensed for prostate enlargement, but is now frequently prescribed “off-label” for hair loss due to its strong effect on reducing dihydrotestosterone (DHT), the hormone responsible for shrinking hair follicles. By lowering DHT levels across the scalp, dutasteride can help slow, stabilise and in many cases, reverse hair thinning.

Unlike topical treatments such as minoxidil (Regaine), dutasteride works from within the body to modulate the hormonal drivers of hair loss. Many men choose it for a reliable, evidence-based option to preserve their hair over time.

How Does Dutasteride Work?

Dutasteride works by blocking the enzyme 5-alpha-reductase (5-AR), which converts testosterone into DHT. High DHT levels cause hair follicles to shrink and produce thinner, shorter hairs. By significantly lowering DHT, dutasteride helps maintain healthier follicles and supports a longer hair growth phase.

Unlike finasteride, which blocks only one form of the enzyme, dutasteride inhibits both Type I and Type II forms of 5-AR, resulting in a much more substantial overall reduction in DHT.

Because DHT is a key hormone linked to male-pattern hair loss, this strong suppression can translate into improved hair coverage and reduced shedding. Improvements develop gradually, and most men begin noticing changes after several months of consistent use.

How Long Does Dutasteride Take to Work?

The time it takes for men taking dutasteride to notice a reduction in hair loss can vary widely from person to person. One study indicated that 77% of men taking dutasteride had improved hair thickness and density, as evidenced by clinical photography, after 24 weeks. Patients often report that it may take a year or longer to see a significant improvement in hair coverage.

Because hair follicles grow slowly, it may take several months of ongoing use before changes become noticeable. Stopping treatment will gradually allow DHT levels to rise again, which may cause hair thinning to return.

Dutasteride Results

Dutasteride is widely recognised as an effective prescription treatment for male-pattern hair loss. Because it reduces DHT levels more effectively than finasteride, it often yields greater improvements in hair density and coverage, especially in men with more advanced thinning.

A key clinical trial published in the Journal of the American Academy of Dermatology compared different doses of dutasteride (0.05-2.5 mg) with finasteride 5 mg or placebo over 24 weeks. Dutasteride showed significantly greater increases in hair count and hair thickness.

Some notable findings from this study include:

• Up to 90% reduction in serum DHT (versus around 70% with finasteride).
• A 51% reduction in scalp DHT when taking 0.5mg of dutasteride.
• Greater mean increase in hair count at 24 weeks compared with finasteride.

Meanwhile, a 2010 study that compared dutasteride 0.5 mg with placebo over 6 months demonstrated:

• Visible regrowth was observed in many men after 6 months
• Improved density, particularly in the crown

A larger long-term analysis from Korea involving more than 400 men also found that dutasteride led to stronger regrowth outcomes and sustained hair improvements well beyond the first year of treatment.

While results vary among individuals, the overall evidence strongly supports dutasteride as a reliable option for men seeking a more effective approach to DHT-related hair loss.

How to Take Dutasteride for Hair Loss

Dutasteride is taken by mouth as a 0.5 mg capsule, swallowed whole with water. Do not chew or break it open, as contact with the capsule’s contents may cause a sore throat or mouth.

It doesn’t matter whether you take it with food, but taking it at the same time each day can help you stay consistent. Regular daily use helps maintain stable DHT levels, which are essential for long-term hair improvement.

Dutasteride Dosage for Hair Loss

The usual clinician-prescribed/off-label dose used for male-pattern hair loss is 0.5 mg once daily. Dutasteride works gradually, so men usually see results building over three to six months, with continued improvement for up to a year or more. Your clinician will advise you on the required treatment duration.

What if You Miss a Dutasteride Dose

Do not take an extra capsule if you miss a dose of dutasteride. Instead, just take your next dose at the usual time. If you find you are regularly forgetting to take medication, you may need to talk to your clinician about options available to you.

If You Take Too Much Dutasteride

Contact your doctor or pharmacist for advice if you take too many dutasteride capsules.

What Happens When You Stop Taking Dutasteride?

If you stop taking Dutasteride, you may not immediately notice any changes. However, hair loss is likely to return over time. Do not stop taking dutasteride without first consulting your doctor or pharmacist. Reducing hair loss requires continual daily use of dutasteride, and it may take 6 months or more to notice visible changes.

Dutasteride Side Effects and Cautions

Like any medication, dutasteride use can cause unwanted side effects and may not be suitable for everyone. Review the following information carefully to determine whether dutasteride is right for you. Having a clear understanding of what to expect can be invaluable in making an informed decision about what treatments to use.

Side Effects of Dutasteride

Dutasteride is usually well-tolerated. If you experience side effects from dutasteride use, contact your prescribing clinician, GP, or pharmacist for advice. Please consult the information below to determine whether dutasteride is right for you.

Potential Dutasteride side effects include:

More information about potential Dutasteride side effects can be found in the Patient Information Leaflet included with the medication. You can also report any adverse reactions to the treatment using the MHRA’s Yellow Card Scheme.

Allergic Reaction

Dutasteride is usually well-tolerated, but it is important to be aware of all potential adverse effects. While rare, allergic reactions to dutasteride can occur. Signs of an allergic reaction include:

• Skin rash (which may be itchy)
• Hives (raised, itchy welts on the skin)
• Swelling of the eyelids, face, lips, arms, or legs

If you experience any of these symptoms, contact your doctor immediately and stop taking dutasteride.

Are Dutasteride Side Effects Permanent?

The majority of side effects from medication use stop when the medication is no longer used, and it has had time to clear the body. However, because dutasteride alters your hormonal balance, side effects may take longer to fully resolve. Difficulty achieving and maintaining an erection, a reduced sex drive, and difficulty with ejaculation can all persist for some time after stopping dutasteride.

Consult a clinician if you are concerned about ongoing side effects. It is usually recommended that you do not stop taking dutasteride without first seeking medical advice.

Dutasteride Interactions and Warnings

Like all medications, Dutasteride may not be suitable for everyone. It has the potential to interact with other treatments or cause adverse effects. It’s therefore essential to have a clear understanding of what to expect, so you can make a more informed decision about whether it is suitable for you.

Do not take Dutasteride if you:

• Are allergic to dutasteride, other 5-alpha reductase inhibitors, or any of the other ingredients
• Have severe liver disease

Please note that this medication is for men only. It must not be used by women, children, or adolescents.

Warnings and Precautions

Before you start taking Dutasteride, it’s important to consult your prescribing clinician if any of the following apply to you:

• You are taking an alpha-blocker, such as tamsulosin. Some studies have shown an increased risk of heart failure (the inefficient pumping of blood around the body).
• You have liver problems, as you may need additional tests during dutasteride treatment.
• You are female, as dutasteride is only prescribed for use by males

You should also be aware of the following safety information:

• Dutasteride affects a blood test for prostate-specific antigen (PSA), which is sometimes used to detect prostate cancer. You must tell your doctor that you are taking dutasteride when you have a PSA test, and you may require more frequent testing.
• In a clinical study of men at increased risk of prostate cancer, men taking dutasteride had a serious form of prostate cancer more often than men who did not take dutasteride. The effect of dutasteride on this serious form of prostate cancer is not clear.
• Dutasteride may cause breast enlargement and tenderness. If these symptoms become troublesome or if you notice a breast lump or nipple discharge, contact your doctor, as this may be a sign of a more serious condition (such as breast cancer).
• Women, children, and adolescents should not handle leaking dutasteride capsules, as the drug can be absorbed through the skin. Wash the affected area with soap and water immediately if contact occurs.

Dutasteride and Other Medications

Tell your prescribing clinician if you are taking, or have recently taken, any medication. This includes medicines you have bought without a prescription.

Some medications can interact with dutasteride, making it more likely that you will experience side effects. These include:

• Verapamil or diltiazem (for high blood pressure)
• Ritonavir or indinavir (for HIV)
• Itraconazole or ketoconazole (for fungal infections)
• Nefazodone (an antidepressant)
• Alpha-blockers (for enlarged prostate or high blood pressure)

You must tell your prescribing clinician if you are taking any of these medications, as the dose you are given may need to be adjusted.

Depression and Mood Changes

Depressed mood, depression, and, less frequently, suicidal thoughts have been reported in patients taking another medicine from the same therapeutic class (5-alpha reductase inhibitor) by mouth.  It is important to know that sexual dysfunction, another side effect of dutasteride use, can also contribute to depressed mood. If any of these symptoms occur, contact your doctor for further medical advice as soon as possible.

Pregnancy and Fertility

It’s important to be careful with sexual intercourse when taking Dutasteride. You should always use a condom during sexual intercourse. Dutasteride has been found in semen. If your partner is or may be pregnant, you must avoid exposing her to your semen, as dutasteride may affect the normal development of a male baby. Dutasteride may also affect male fertility and has been shown to decrease sperm volume, total sperm count, and sperm motility.

Where Can I Buy Dutasteride for Hair Loss in the USA and UK?

Dutasteride is available to purchase in the USA and UK only from registered pharmacies, as it is a prescription-only medication. This is to ensure access to Dutasteride remains safely regulated.

When looking to buy Dutasteride for hair loss, it’s essential to go with a reputable pharmacy you can trust. The General Pharmaceutical Council keeps an up-to-date register of licensed pharmacies.

Do I Need a Dutasteride Prescription?

Yes. Dutasteride is a prescription-only medication (POM). You cannot purchase dutasteride without a prescription from an appropriately trained prescriber. This is to determine whether the treatment is safe and suitable for you.

Can I Get Dutasteride on the NHS?

Dutasteride is not normally available on the NHS for male-pattern hair loss. It may be prescribed on the NHS for other licensed indications, such as benign prostatic hyperplasia, but hair-loss treatment is usually accessed privately. Off-label prescribing by clinicians is based on evidence from rigorous clinical trials. Off-label treatments that are considered primarily cosmetic are not available on the NHS.

Can I Buy Dutasteride Online?

Yes, you can buy Dutasteride online from reputable pharmacies, such as Prescription Doctor, after a brief medical consultation. Simply complete the form at your leisure and answer questions about your medical history and any other treatments you may be taking, so our experienced clinicians can determine if it’s an appropriate treatment for you.

If approved, your medication is dispatched from our General Pharmaceutical Council-registered pharmacy in plain packaging for complete discretion. Orders approved before 3pm on a weekday are also eligible for next-day delivery to your designated UK address.

Dutasteride for Hair Loss: Frequently Asked Questions