How effective is 1mg of finasteride? An analysis of its role in hair loss treatment

October 10, 2025 •

4 min read

Clinical trials have consistently demonstrated the effectiveness of finasteride for male pattern hair loss. It is a medication specifically used for treating this condition by targeting the hormonal cause of hair thinning.

Quick Summary

Finasteride is a proven treatment for male pattern baldness, working by reducing DHT levels. Clinical studies show significant slowing of hair loss and regrowth for many men within 6 to 12 months. Long-term consistency is key for sustained benefits and maintaining hair density over time.

Key Points

Significant DHT Reduction: Finasteride effectively lowers scalp and serum DHT levels, the hormone responsible for male pattern hair loss.
Evidence-Based Efficacy: Clinical trials spanning multiple years demonstrate that finasteride slows hair loss progression and promotes new hair growth in a majority of men.
Appropriate Use: Finasteride is specifically studied and proven effective in clinical trials while minimizing the risk of side effects.
Gradual Results: Expect to see initial improvements within 3-6 months, with more noticeable and significant results becoming evident after 9-12 months of consistent use.
Requires Ongoing Use: To maintain results and prevent further hair loss, continuous daily treatment with finasteride is necessary, as stopping the medication will cause the balding process to resume.
Favorable Long-Term Profile: Long-term studies over several years show sustained efficacy and confirm that finasteride is generally well-tolerated by patients.

The Mechanism Behind Finasteride's Effectiveness

Finasteride is a 5-alpha reductase inhibitor that works by blocking the enzyme responsible for converting testosterone into DHT, a hormone that causes hair follicle miniaturization in men with a genetic predisposition to hair loss. By reducing scalp and serum DHT levels, finasteride helps to halt hair loss and promote regrowth. Because the hair growth cycle is slow, it takes time to see visible results.

A Clinical Look at Finasteride's Results

Clinical trials have shown that finasteride is effective in treating male pattern hair loss, using methods like photographic assessments and hair counts to measure results. Studies over two years indicate significant increases in hair count, with a large majority of men experiencing no further hair loss and many seeing visible regrowth. Patients and investigators have also reported positive improvements in hair appearance.

The Long-Term Efficacy of Finasteride

Continuous, long-term use of finasteride is essential, as stopping treatment will cause DHT levels to rise and reverse the benefits. Long-term studies, including one over 5 years on Korean men, have demonstrated sustained effectiveness, with most patients showing improvement, particularly on the crown. Another 5-year study also confirmed lasting improvements in hair growth and a reduced risk of further visible hair loss.

Understanding the Timeline for Results

Visible results from finasteride are gradual due to the hair growth cycle.

Typical Finasteride Results Timeline:

1–3 Months: Initial Phase: Some temporary shedding may occur as the hair growth cycle resets. No significant regrowth is typically visible.
3–6 Months: Initial Improvements: Shedding often decreases, and some slowing of hair loss or thickening of existing hair may be noticed, with modest regrowth starting for some.
6–12 Months: Clearer Results: More significant improvement in hair density and thickness should become apparent. Consistent daily use is important during this time.
1+ Years: Maximum Benefits: Continued use leads to the most substantial and lasting results, with potential for slight ongoing improvement in hair density.

Comparison: Finasteride vs. Other Options


Feature	Oral Finasteride	Topical Finasteride	Topical Minoxidil
Primary Use	Male pattern hair loss	Male pattern hair loss (off-label)	Male pattern hair loss
DHT Reduction	Significantly lowers scalp and serum DHT	Reduces scalp DHT with less systemic absorption	No effect on DHT; promotes blood flow
Efficacy for Hair Loss	Highly effective, well-studied	Effective, with similar efficacy to oral, possibly safer	Effective; often used in combination with finasteride
Side Effect Profile	Low incidence, mainly sexual side effects	Lower risk of systemic side effects, potential for local irritation	Local scalp irritation, burning, dryness
FDA Approval for Hair Loss	Yes	No (prescription off-label)	Yes (over-the-counter and prescription)

Combining finasteride with topical minoxidil can lead to superior results for some due to their different actions. Topical finasteride is a potential alternative for those concerned about systemic side effects, although it lacks FDA approval for hair loss.

Conclusion

Finasteride is an effective, clinically-backed treatment for male pattern baldness, working by reducing DHT. Results are gradual, typically appearing within 3-6 months and peaking after 1-2 years of consistent use. Long-term studies show lasting effectiveness, but continuous use is necessary to maintain benefits. For men with mild to moderate hair loss, finasteride offers significant therapeutic effects with a favorable safety profile. Consultation with a healthcare provider is recommended to determine if it is suitable for your situation.

Potential Side Effects

Though generally well-tolerated, finasteride can cause side effects, most often reversible sexual issues like decreased libido and erectile dysfunction in a small percentage of users. Rarely, side effects may persist after stopping the medication.

Important Considerations

Consistency is Key: Regular use is essential for sustained effectiveness.
Early Intervention: Finasteride is most effective for early-stage hair loss and less so for completely bald areas.
Professional Consultation: Always consult a healthcare provider before starting finasteride to discuss risks, benefits, and suitability.
Fertility: Some men have reported reversible infertility while on finasteride, which should be discussed with a doctor if planning to have children.

The Verdict

For most men with male pattern hair loss, finasteride is a strong, evidence-based treatment that effectively halts hair loss and promotes regrowth. While results take time and consistent use, scientific data and long-term studies support its use as a core treatment option. With professional guidance, it is one of the most reliable medical solutions for androgenetic alopecia.

What to Do If You're Unsure

If you are unsure about finasteride, consult a dermatologist or hair loss specialist. They can evaluate your condition, discuss potential risks and benefits, and help you decide on the best treatment plan. Tracking progress with photos can also help assess its effectiveness for you.

Frequently Asked Questions

While finasteride starts working immediately internally, visible results typically take time. Initial improvements can be seen within 3 to 6 months, and more significant hair growth is usually noticeable after 9 to 12 months of consistent daily use. Maximum benefits are often realized after two years.

If you stop taking finasteride, the DHT levels in your body will return to their previous state within a few weeks. Consequently, any hair regrowth or halted hair loss you experienced will likely reverse within 6 to 12 months, and the hair loss process will resume.

Finasteride can be effective for a receding hairline, but studies suggest it often works better for balding on the crown of the head. Clinical trials have shown improvements in the anterior mid-scalp and frontal areas, but results can vary.

No, side effects from finasteride are uncommon and usually mild. The most frequently reported are sexual side effects like decreased libido and erectile dysfunction, which affect a small percentage of users. Most side effects are reversible upon discontinuation.

Yes, combining finasteride with topical minoxidil is a common strategy and has shown superior results for many patients. The two medications have complementary mechanisms of action, addressing hair loss from different angles.

The appropriate use of finasteride for male pattern hair loss is determined by a healthcare professional based on individual needs and clinical guidelines. This approach has been extensively studied and proven effective in clinical trials while minimizing the risk of side effects.

For treating male pattern hair loss, the typically used amount of finasteride is not significantly less effective than a higher amount. A higher amount is used for benign prostatic hyperplasia (BPH) and may come with a higher risk of side effects, making it unnecessary for hair loss treatment.