Finasteride vs Minoxidil

May 21, 2025/Andrew Le

When you have hair loss, you might notice more hair in the shower drain or a thinning spot that slowly gets bigger. While many products promise results, two treatments—finasteride and minoxidil—stand out the most.

But how do they really work? Finasteride blocks the hormone behind shrinking hair follicles. Minoxidil, on the other hand, wakes up dormant follicles and boosts blood flow. Each option has its own strengths, risks, and ideal users. Some people even combine both for better results.

In this article, you’ll learn how finasteride and minoxidil work, how to use them, what side effects to watch for, and which one might work best for you.

🔑Key Takeaways

➤ Finasteride blocks the hormone DHT, which causes hair follicles to shrink, while minoxidil helps wake up resting follicles and boosts blood flow to support new growth.

➤ Finasteride is taken as a pill once a day, while minoxidil can be applied to the scalp or taken by mouth, depending on the form and dose.

➤ Minoxidil usually starts showing results in 8 weeks, with peak effects at 4 months, but only if you keep using it.

➤ Finasteride takes about 3 to 6 months to work, and stopping it often leads to hair loss returning within a year.

➤ Minoxidil works for both men and women, while finasteride is more effective in men and shows mixed results in women.

➤ Finasteride may cause serious side effects like sexual problems, mood changes, and long-term risks, especially in younger men.

➤ Minoxidil’s side effects are usually mild when applied to the scalp but can be more serious when taken by mouth.

Mechanism of Action/How It Works

Finasteride works by lowering DHT, the hormone that causes hair loss while Minoxidil helps hair grow by improving blood flow and waking up resting hair follicles

Finasteride

As described in a 2024 book, Finasteride blocks the action of the enzyme 5-alpha reductase—specifically the type II and type III forms. These enzymes convert testosterone into dihydrotestosterone (DHT), a more potent hormone responsible for shrinking hair follicles in male pattern baldness. 

By reducing DHT levels, finasteride helps slow down hair loss and allows existing hair follicles to recover. However, it has little effect on the type I enzyme, which is mostly found in the skin and sebaceous glands.

Because DHT is strongly linked to both prostate growth and hair loss, lowering its levels through finasteride helps with both conditions. The reduction in DHT levels also prevents further damage to hair follicles and, over time, allows for regrowth in some patients. But this effect lasts only as long as the drug is taken. Once stopped, DHT levels return, and hair loss usually resumes.

Minoxidil

Minoxidil works very differently. According to a 2023 book, the exact way minoxidil stimulates hair growth is not fully understood. However, the process begins when the enzyme sulfotransferase in the scalp converts minoxidil into its active form, minoxidil sulfate. This active form is believed to act on dormant hair follicles by shortening the telogen (resting) phase, allowing hair to enter the anagen (growth) phase sooner. 

It also prolongs the anagen phase, which leads to longer and thicker hair strands. These changes often become noticeable after around 8 weeks and peak at 4 months.

Minoxidil works partly by affecting potassium channels in the hair follicles and surrounding blood vessels. This action leads to better blood flow around the follicles (vasodilation), promoting a healthier environment for hair to grow. 

In addition, it may increase vascular endothelial growth factor (VEGF) and prostaglandin production, both of which support hair development. It also shows antifibrotic effects and may counteract androgen-related hair thinning by acting like an epidermal growth factor, keeping hair follicles younger and more active through the beta-catenin pathway.

Topical minoxidil causes hair follicles to shift from resting to growing earlier and makes the follicles larger. Though it’s believed this effect may also happen in humans, the link between potassium channel activation and hair growth is not fully proven because it’s unclear if those channels even exist in human follicles. 

Still, in lab tests, minoxidil has been shown to boost cell growth, reduce collagen formation (which might help with scarring hair loss), and trigger factors like VEGF and prostaglandins that support hair growth.

Dosage and Administration

Finasteride is taken daily—1 mg for hair loss and 5 mg for prostate issues—while minoxidil can be used as a topical or oral treatment, with different doses for each form and condition.

MedicationFormDosageUse Case
FinasterideOral Tablet1 mg once dailyMale pattern hair loss
FinasterideOral Tablet5 mg once dailyBenign prostatic hyperplasia (BPH)
MinoxidilTopical Solution1 mL twice dailyHair loss (men)
MinoxidilTopical FoamHalf capful twice daily (men) / once daily (women)Hair loss
MinoxidilOral Tablet0.625 mg to 5 mg once dailyHair loss (off-label)
MinoxidilOral Tablet5–40 mg daily (in divided doses)Severe hypertension

Finasteride

According to a 2024 book, finasteride is available in two oral tablet strengths—1 mg and 5 mg—each intended for different conditions. For male pattern hair loss, the recommended dose is 1 mg taken once daily. 

For benign prostatic hyperplasia (BPH), the standard dose is 5 mg once daily. The tablet should be swallowed whole with water and must not be crushed or broken. It’s safe to take it with or without food, but consistency is key—you should take it at the same time each day. 

It may take at least three months to see results for hair loss and up to six months for BPH. If you stop taking finasteride, the effects wear off. Hair loss usually resumes within 12 months, and prostate symptoms return in a few months.

Treatment duration varies. You may need to take it for several months or even years, depending on your condition. For instance, when used for hair loss, new growth is maintained only if the medicine is continued. If you forget a dose, it’s advised to skip it and resume your normal schedule—do not double up. 

Women who are or may become pregnant must avoid handling crushed or broken tablets due to the risk of birth defects in male fetuses.

Minoxidil

Minoxidil comes in both topical and oral forms, and each has its own dosing guidelines. 

Topical minoxidil is commonly available in 2% and 5% strengths. 

For hair growth, men are generally advised to apply 1 mL of the solution—or half a capful of the foam—twice daily directly to the scalp. Women typically use the 2% solution twice daily or the 5% foam once daily. The scalp must be clean and dry before application. 

After applying, you should allow the medicine to dry for at least 2 to 4 hours and avoid using a hairdryer. Skipping this step can reduce the effectiveness or increase absorption, which may cause side effects.

Oral minoxidil, on the other hand, is a prescription medication. Doses for hair loss usually range from 0.625 mg to 5 mg daily. Higher doses, such as 10 to 40 mg per day, are reserved for severe hypertension and must be closely monitored due to possible cardiovascular effects. 

Unlike the topical form, oral minoxidil is more consistently converted to its active metabolite, minoxidil sulfate, in the liver. 

Missing a dose of either oral or topical minoxidil isn’t dangerous, but doubling up is discouraged. Regular monitoring—like pulse checks and daily weight tracking—is also recommended, especially for those on the oral form, to catch early signs of adverse effects like fluid retention or rapid heartbeat.

Efficacy

Finasteride is highly effective at slowing or stopping hair loss in most men, while minoxidil helps regrow hair and reduce shedding in both men and women, though its effect may fade over time without continued use.

Finasteride

According to a study, finasteride 1 mg daily has been shown to be highly effective for men with mild to moderate androgenetic alopecia. In three large placebo-controlled trials with 1,879 men, 86% either maintained or gained hair after one year of treatment. Only 14% continued to lose hair, compared to 58% of those who took a placebo. This clearly shows that finasteride can help most men slow or stop hair loss. Even better, studies have shown that 9 out of 10 men experience long-term benefits when using the drug daily over several years.

A five-year study in Korean men also demonstrated long-lasting results. Among 126 patients who used finasteride 1 mg for five years, 85.7% showed visible improvement. The effectiveness also varied by the area of hair loss. For example, 89.7% saw progress in the vertex area (top of the head), while 61.2% improved in the frontal region. Only a small percentage experienced hair loss after their peak improvement—just 10.3% in the vertex type and 16.2% in the frontal type. These findings show that finasteride can keep working over time, especially on certain parts of the scalp.

However, when it comes to women, results are mixed. According to a meta-analysis of nine studies involving 490 female patients, no significant increase in hair density was found after using finasteride. Instead, the treatment was rated based on visible improvement. The response rate across all studies was 81%, with better results in women who took higher doses. In those taking low doses, the response rate was 70%. Despite this, the studies showed high inconsistency, and the reliability of these findings was limited due to the small number of well-controlled trials.

Minoxidil

According to a study, topical minoxidil has shown visible effectiveness in treating androgenetic alopecia (AGA) in both men and women. 

In their five-year study, 2% topical minoxidil peaked in efficacy at year one, then gradually declined. This shows that minoxidil can help initially, but its effect may not last as long without continued use. Both 2% and 5% topical forms—whether solution or foam—showed similar levels of effectiveness, with no strong evidence that one was significantly better than the other.

In a separate observational study, 984 men used 5% topical minoxidil twice daily for 12 months. The results were promising. Physicians observed that 62% of the patients had a smaller balding area, while only 2.9% had a worse condition. When it came to hair regrowth, 15.9% of patients rated the product as very effective, and 47.8% found it effective. Even more compelling, the number of hairs lost during washing dropped from an average of 69.7 to 33.8 by the end of the study. That’s more than a 50% reduction. This supports the idea that minoxidil not only regrows hair but also helps prevent further shedding.

Moreover, research confirmed that minoxidil remains the mainstay for AGA treatment due to its favorable efficacy profile. Although the exact way it works is not fully understood, patients with higher sulfotransferase activity in their hair follicles tend to respond better. In simpler terms, the way your body processes minoxidil might affect how well it works for you. 

Minoxidil is also available in oral and sublingual forms, which, according to a study, may be more effective than topical versions, especially when used at 5 mg/day in men. Still, oral forms are not FDA-approved and should be used with caution.

✂️ In Short

For finasteride, visible results usually start after 3 to 6 months of daily use, and consistent treatment can maintain or improve hair growth for at least 5 years. However, stopping the medication often leads to a return of hair loss within 12 months.

For minoxidil, results typically begin to appear after 8 weeks, with the best effects seen around the 4-month mark and peaking at 1 year. Continued use is necessary, as hair regrowth gradually declines after the first year if treatment is stopped.

Side Effects

Finasteride can cause sexual, physical, and mental side effects—some mild, some lasting—while minoxidil is usually safer on the skin but may cause serious problems if taken by mouth.

Finasteride

Finasteride may cause a wide range of physical, sexual, and psychological side effects. While some are common and mild, others are rare but serious. Side effects may appear during use or persist even after stopping. A small percentage of users, especially younger men, have reported lasting effects, now referred to as post-finasteride syndrome (PFS).

All reported side effects of finasteride include:

  • Trouble getting or keeping an erection
  • Decreased sexual desire (loss of libido)
  • Reduced volume of semen or trouble ejaculating
  • Testicular pain
  • Depression or low mood
  • Suicidal thoughts or behavior
  • Breast enlargement
  • Breast tenderness or lumps
  • Nipple discharge
  • Rash
  • Itching
  • Hives
  • Facial swelling
  • Lip swelling
  • Difficulty breathing or swallowing
  • Dizziness or fainting
  • Persistent sexual dysfunction (linked to PFS)
  • Anhedonia (inability to feel pleasure)
  • Insomnia
  • Anxiety
  • Decreased sperm count
  • Lower semen volume
  • Reduced sperm motility
  • Reduced sperm concentration
  • Increased risk of high-grade prostate cancer
  • Risk of breast cancer in men
  • Fatigue (in women)
  • Menstrual cycle changes (in women)
  • Increased body hair (in women)
  • Gastrointestinal discomfort (in women)
  • Headaches (mostly in women)
  • Dizziness (in women)
  • Decreased libido (in women)
  • Spontaneous abortion or fetal harm if handled during pregnancy

Finasteride’s side effects may last months or even years depending on dose, duration, and individual factors. Post-finasteride syndrome is still being researched but is already linked to over 89 reported suicides worldwide. Some men never fully recover.

Minoxidil

Minoxidil is mostly well tolerated, especially when used topically. Most side effects are mild and related to skin irritation. Systemic reactions are rare and usually occur only when the medication is used improperly or in oral form. Oral minoxidil carries a higher risk, especially at higher doses.

All reported side effects of minoxidil include:

  • Itching at the application site
  • Redness or rash on the scalp
  • Burning sensation
  • Peeling or flaking of the scalp
  • Acne at the site of application
  • Inflammation of hair roots
  • Swelling of the face
  • Changes in hair color
  • Changes in hair texture
  • Facial hair growth (especially in women)
  • Increased hair shedding during early use
  • Blurred vision
  • Chest pain
  • Fast or irregular heartbeat
  • Lightheadedness or dizziness
  • Fainting
  • Headaches
  • Numbness or tingling in hands, feet, or face
  • Flushing
  • Swelling of hands, feet, or lower legs
  • Rapid weight gain
  • Shortness of breath (rare, systemic absorption)
  • Confusion (rare)
  • Insomnia (oral form)
  • Gastrointestinal discomfort (oral form)
  • Low blood pressure (hypotension)
  • Rapid heartbeat (tachycardia)
  • Drowsiness (rare)

Although some side effects—like hair shedding or scalp irritation—are temporary, others (especially systemic ones) can be more serious. Oral minoxidil should only be used under supervision. Again, it is not FDA-approved for hair loss and may cause more side effects in women, including dizziness and menstrual changes.

Cost

Based on prices from Cost Plus Drugs, finasteride and minoxidil tablets cost around $5 to $6 per 30-count bottle, saving buyers up to $64 compared to retail prices.

DrugStrengthCostRetail PriceSavings
Finasteride1mg$5.82$70.20$64.38
Finasteride5mg$6.16$50.10$43.94
Minoxidil2.5mg$5.83$17.10$11.27
Minoxidil10mg$6.20$24.00$17.80

Finasteride

Finasteride comes in two strengths—1mg and 5mg—and is sold in 30-count tablets. The 1mg version costs $5.82 for a 30-count supply. Meanwhile, the 5mg strength is priced slightly higher at $6.16 for the same count. 

These prices are significantly lower than traditional retail pharmacy prices. For example, a 30-count bottle of 1mg finasteride typically costs $70.20 at other pharmacies, which means users save $64.38 when buying from Cost Plus. Similarly, the 5mg version is usually $50.10 at retail, so users save $43.94.

Minoxidil

Minoxidil is offered in two strengths—2.5mg and 10mg—with a 30-count bottle for each. The 2.5mg version costs $5.83, while the 10mg version is $6.20. 

The 2.5mg tablet normally costs $17.10 at other pharmacies, so this lower price saves customers $11.27. The 10mg strength retails for $24.00, which means a total savings of $17.80 when ordered through Cost Plus.

Wrap Up

Finasteride and minoxidil offer two different paths to treating hair loss. One blocks a hormone linked to shrinking hair follicles, while the other boosts blood flow to help new hair grow. 

Finasteride works best for men and requires long-term use, but it may cause serious side effects. Minoxidil, especially the topical kind, is safer and works for both men and women—though the results may fade without regular use. 

Frequently Asked Questions

Can I use finasteride and minoxidil together?

Yes, some doctors recommend using both. Finasteride lowers DHT to prevent more hair loss, while minoxidil helps grow new hair. When used together, they may give better results than using just one. Talk to your doctor before combining them.

Is it okay to use minoxidil on a sunburned scalp?

No, don’t use it on sunburned, irritated, or broken skin. This can increase how much medicine gets into your body and may raise the risk of side effects. 

What should I do if I miss a dose of either drug?

Just skip the missed dose and take your next one at the usual time. Don’t double up. Taking too much won’t help and may raise your risk of side effects.

Sources

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