Does Topical Finasteride Work?

Article Summary

Topical finasteride is quickly emerging as a compelling alternative to oral finasteride for treating androgenic alopecia, promising similar hair regrowth with significantly fewer systemic side effects. But does topical finasteride work? In this article, we break down how topical finasteride works, how it compares to the oral version, what formulations and doses are safest, and how to boost effectiveness with add-ons like minoxidil or microneedling. Whether you’re new to finasteride or looking to reduce your risk profile, this is your evidence-based guide to making the switch.

Full Article

Oral finasteride has established itself as a highly effective treatment for androgenic alopecia (AGA) and is widely prescribed around the globe. Its success can be largely attributed to its proven ability to slow hair loss and stimulate regrowth by inhibiting the conversion of testosterone to DHT, the hormone chiefly responsible for follicular miniaturization. 

However, despite its well-documented efficacy, oral finasteride has become equally notorious for its potentially systemic side effects. Some men experience adverse effects such as decreased libido, erectile dysfunction, mood changes, and even persistent symptoms after discontinuation, a phenomenon called post-finasteride syndrome.^[1]Diviccaro, S., Melcangi, R.C., Giatti, S. (2019). Post-finasteride syndrome: an emerging clinical problem. Neurobiology of Stress. 12. 100209. Available at: https://doi.org/10.1016/j.ynstr.2019.100209 This reputation has prompted many to seek alternatives that are both effective and safer for long-term use.

Recently, topical finasteride formulations have garnered attention as a promising alternative. By delivering the medication directly to the scalp, topical finasteride aims to minimize systemic absorption and thereby reduce the likelihood of side effects while still providing the benefits of DHT inhibition where it matters most. This alternative approach has piqued the interest of both patients wary of systemic issues and clinicians seeking tailored treatments.

In this article, we will examine whether topical finasteride can serve as a viable alternative to its oral counterpart. The main focus will be on answering three questions:

1. Can topical finasteride effectively regrow hair in those affected by AGA?
2. Does it match the efficacy results seen with oral finasteride?
3. Can it reduce hair loss while offering a more favorable side effect profile?

Ulo offers finasteride options that range from low to high dose finasteride – allowing you to be flexible in your treatment choices.

Oral vs. Topical Finasteride

Some research directly compares oral finasteride (1 mg daily) with various concentrations of topical finasteride, aiming to match hair regrowth efficacy while minimizing systemic side effects. Let’s take a look at a couple of examples:

Study 1 – Piraccini et al., 2022 (Phase III RCT, 24 weeks)

• Compared topical finasteride (0.25% spray) to oral finasteride (1 mg/day) and placebo in men with AGA.^[2]Piraccini, B.M., Blume-Peytavi, U., Scarci, F., Jansat, J.M., Falques, M., Otero, R., Tamarit, M.L., Galvan, J., Tebbs, V., Massana, E., Topical Finasteride Study Group. Efficacy and safety of … Continue reading
• The increase in hair count on a defined scalp area was similar for topical and oral finasteride, both outperforming the placebo, suggesting comparable clinical benefit.
• Systemic finasteride (oral) reduced mean serum DHT by 55.6%,  whereas topical finasteride reduced it by 34.5%. Plasma finasteride exposure from topical application was over 100 times lower than from oral administration. 
• Both had similar low rates of mild side effects, but sexual side effects, but sexual side effects were more associated with oral treatment. 
• Caveats: The “target area” measured may not represent the full scalp effects; although systemic absorption, albeit at a much lower level with topical application, still occurred and varied by formulation. 

Study 2 – Bhura, 2013 (RCT, 8 months)

• Parallel-group comparison in male AGA, tracking hair density and systemic DHT.^[3]Bhura, M. (2013). Comparative Analysis of Topical and Oral Finasteride in Androgenetic Alopecia: Impact on Hair Growth, Systemic Absorption, and Adverse Effects. Indian Journal of Basic and Applied … Continue reading 
• Oral finasteride resulted in slightly superior increases in hair number and thickness, although the difference was not statistically significant.
• Oral finasteride significantly reduced systemic DHT and caused more sexual side effects; topical finasteride led to minimal serum DHT changes and almost no systemic side effects, with most reactions being local (e.g., irritation).
• Those worried about long-term systemic effects preferred topical use, despite slightly less pronounced gains.

Study 3 – Hajheydari, 2009 (RCT, 6 months)

• Compared a 1% topical gel + placebo tablet with oral finasteride 1 mg/day + placebo gel.^[4]Hajheydari, Z., Akbari, J., Saeedi, M., Shokoohi, L. (2009). Comparing the therapeutic effects of finasteride gel and tablet in treatment of the androgenetic alopecia. Indian Journal of Dermatology, … Continue reading 
• Both the gel and tablet produced statistically significant increases in total hair count and terminal hair count.
• There were no significant differences in hair thickness, hair count, or size of the bald area between the two groups. 

Mechanism of Action

Finasteride Pharmacodynamics

Finasteride is a competitive inhibitor of 5α-reductase, primarily targeting the type II isoenzyme at therapeutic doses, which predominates in the hair follicles and prostate. As mentioned above, this enzyme catalyzes the conversion of testosterone to DHT. 

At higher tissue concentrations, finasteride can also inhibit type I 5α-reductase, which is primarily found in the skin and sebaceous glands; however, its clinical significance for hair loss at standard doses is limited. By selectively inhibiting the type II enzyme, finasteride effectively lowers local and systemic DHT levels.^[5]Finn, D.A., Beadles-Bohling, A., Beckley, E.H., Ford, M.M., Gililland, K.R., Gorin-Meyer, R.E., Wiren, K.M. (2006). 12(1). 53-76. A New Look at the 5α-reductase Inhibitor Finasteride. CNS Drug … Continue reading 

What is Finasteride’s Effect on DHT Suppression?

Finasteride’s effect on DHT suppression is characterized by a logarithmic dose-response curve, meaning that even very low systemic levels can produce a marked reduction in both serum and scalp DHT. Most of the drug’s inhibitory action is achieved at low doses, with additional dosing yielding only marginal further effect.

As a result, even minimal “leakage” of topically applied finasteride into the bloodstream can decrease DHT levels elsewhere in the body.

Pharmacokinetic studies show that inhibition of type-II 5ɑ-reductase reaches saturation at typical clinical dosage, while type-1 enzyme inhibition requires much higher concentrations. This nonlinear pharmacodynamic profile explains both the strong efficacy and the wide safety margin of topical finasteride: a small amount achieves most of the desired effect, so careful formulation is crucial to maximize scalp delivery while minimizing unwanted systemic exposure.^[6]Suzuki, R., Satoh, H., Ohtani, H., Hori, S., Sawada, Y. (2010). Saturable Binding of Finasteride to Steroid 5ɑ-reductase as Determinant of Nonlinear Pharmacokinetics. Drug Metabolism and … Continue reading 

What the Science Says

Topical finasteride has been studied across a 200-fold concentration range, from 0.005% solutions to 1% gels. Collectively, these trials demonstrate meaningful reductions in shedding and measurable regrowth; however, systemic exposure increases with dose and vehicle potency.

Study	Concentration & Vehicle	Hair Growth-Outcomes	Systemic/Serum Findings
Mazzarella 1997, single-blind, 52 men/women, 16 months.	0.005% hydro-alcoholic solution	73% reported “high effectiveness”; wash-test hair counts improved; slowed shedding by month 6	No significant change in plasma DHT or testosterone; absorption was negligible.
Tanglertsampan 2012 RCT, 33 men, 24 weeks.	0.1% lotion + 3% minoxidil	The combination arm gained more hairs/cm2 and thicker shafts than minoxidil alone.	Local irritation mild; systemic parameters not monitored.
Datta 2021 double-blind trial, 35 participants completed, 6 months.	0.1% lotion +5% minoxidil vs oral 1 mg.	The topical combination was non-inferior to oral minoxidil for reducing the Hamilton-Norwood stage.	Sexual adverse events only occurred in the oral group; topical was well-tolerated.
Caserini 2016 OK study, 50 men, 1 week; Piraccini 2022 phase III, 323 completers, 24 weeks.	0.25% solution.	-70% scalp DHT after once-daily 1 mL; +20.2 hairs in 1 cm2 target area at 24 weeks – numerically equal to oral 1 mg.	100-200 μL doses reduced serum DHT by only 24-26%; 400 μL treatment reduced levels by 44-48%; Cmax was more than 100 times lower than oral.
Rossi 2020 retrospective, 69 women, 12-18 months.	0.5% lotion (postmenopausal women)	The Finasteride + minoxidil group scored higher on a 7-point global scale compared to the 17ɑ-estradiol + minoxidil group.	No androgenic side effects reported.
Hajheydari 2009 DB-RCT, 45 men, 6 months.	1% gel	Increases in total and terminal hair counts matched those of oral 1 mg; the bald area remained unchanged.	Serum DHT not assayed; clinical side-effects minimal.

Low-Dose Takeaways

Even a micro-dose of 0.005% twice daily (~0.1 mg/day) curbed shedding and improved density without measurable systemic suppression, making it an attractive option for highly risk-averse users.^[7]Mazzarella, F., Loconsole, F., Cammisa, A., Mastrolonardo, M., Vena, G.A. (1997). Topical finasteride in the treatment of androgenic alopecia. Preliminary evaluations after a 16-month therapy course. … Continue reading

Mid-Range (0.1-0.25%)

Adding 0.1% finasteride to minoxidil amplifies regrowth compared to minoxidil alone, while standalone 0.25% sprays deliver oral-level scalp DHT blockade, maintaining serum exposure roughly one-tenth that of tablets. Dose and volume are critical.^[8]Caserini, M., Radicioni, M., Leuratti, C., Terragni, E., Iorizzo, M., Palmieri, R. (2016). Effects of a novel finasteride 0.25% topical solution on scalp and serum dihydrotestosterone in healthy men … Continue reading

High-Dose (0.5-1%)

Topical finasteride options at 0.5% have been shown to extend benefits to female pattern hair loss with good tolerability.^[9]Rossi, A., Magri, F., D’Arino, A., Pigliacelli, F., Muscianese, M., Leoncini, P., Caro, G., Federico, A., Fortuna, M.C., Carlesimo, M. (2020). Efficacy of Topical Finasteride 0.5% vs 17ɑ-Estradiol … Continue reading

Why Formulation and Dose Matter

1. The vehicle drives absorption: according to the studies, hydro-alcoholic sprays penetrate faster than gels or liposomes, explaining divergent serum DHT curves at equal nominal strengths. 
2. Daily drug load, not percentage alone, predicts systemic spill over; 0.025% at 400 μL approaches the systemic impact of oral dosing, whereas 100 μL does not.
3. Combination therapy often allows for a lower finasteride concentration to achieve equal cosmetic benefits, thereby minimizing exposure.

Minimizing Systemic Absorption

While topical finasteride offers an option for minimizing systemic exposure, several key variables influence the amount that enters the bloodstream, and this can occur surprisingly quickly.

Key Factors Affecting Systemic Absorption

• Carrier Agent: The vehicle used to deliver finasteride dramatically alters absorption. Alcohol-based (ethosomal) carriers enhance drug penetration through the skin and into deeper layers like the dermis much more than conventional liposomes, which tend to remain more superficial. One study found that ethosomes resulted in approximately six times greater dermal accumulation than liposomes, highlighting the direct impact of carrier choice on systemic exposure.^[10]Rao, Y., Zheng, F., Zhang, X., Gao, J., Liang, W. (2008). In Vitro Percutaneous Permeation and Skin Accumulation of Finasteride Using Vesicular Ethosomal Carriers. AAPS PharmSciTech. 9(3). 860-865. … Continue reading
• Time on Scalp Before Washing: The longer finasteride remains on the scalp before washing, the greater the chance for absorption through the skin. Washing off too soon reduces drug uptake, but leaving it for extended periods increases both local efficacy and systemic exposure. Guidelines often recommend allowing at least 4-6 hours on the scalp, though this can vary by formulation. 
• Frequency of Use: If you can keep topical finasteride on your scalp for at least 10-12 hours, once-daily applications of low-dose topical finasteride might be beneficial. For those who can only tolerate finasteride for 4-6 hours, twice-daily applications may be better. You can read more about how often topical finasteride should be applied here.
• Individual Skin Permeability: Personal factors, including skin thickness, barrier integrity, genetics, and even scalp conditions, can strongly influence how much finasteride penetrates the scalp. Individuals with more permeable skin may absorb a greater amount of the drug systemically, increasing the risk of side effects.^[11]Brito, S., Baek, M., Bin, B-H. (2024). Skin Structure, Physiology, and Pathology in Topical and Transdermal Drug Delivery. Pharmaceutics. 16(11). 1403. Available at: … Continue reading 

How To Maximize Gains and Minimize Risk

To achieve the best results and reduce the likelihood of side effects, there are several strategies you can employ:

• Establish a Baseline with Serum DHT Testing

Before starting topical finasteride, get a baseline measurement of your serum DHT levels through a blood test. This serves as a reference to assess the extent to which systemic DHT is affected by your treatment. 

• Retest After 30 Days

After one month of consistent topical use, repeat the serum DHT test under the same conditions (preferably in the morning, fasted, and at a similar time of day). This helps you gauge systemic absorption and adjust your regimen if your serum DHT levels drop excessively. Hormone levels fluctuate based on daily rhythms, food intake, and stress, so always test under similar circumstances: morning, fasted, and ideally before applying the day’s finasteride.

• Avoid Confounding Supplements

Avoid supplements that may directly affect DHT, such as those that increase DHT (e.g., creatine) or quercetin (which may lower it). This ensures your test results and progress are a direct reflection of the topical finasteride.^[12]van der Merwe, J., Brooke, N.E., Myburgh, K.H. (2009). Three weeks of creatine monohydrate supplementation affects dihydrotestosterone to testosterone ratio in college-aged rugby players. Clinical … Continue reading,^[13]Ma, Z., Nguyen, T.H., Huynh, T.H., Do, P.T., Huynh, H. (2004). Reduction of rat prostate weight by combined quercetin-finasteride treatment is associated with cell cycle deregulation. Journal of … Continue reading 

• Be Patient – It Takes Time

Visible improvements often require 12-24 months. Don’t make hasty adjustments if you don’t see immediate changes; hair cycles are slow. 

• Track Your Progress Objectively

Use standardized, high-quality photo documentation, same angle, lighting, and distance each time, to objectively monitor changes in hair density and coverage.

Combination Therapies

Robust evidence supports the use of combination therapies for AGA, with multi-modal approaches consistently outperforming monotherapy in terms of efficacy and speed of regrowth.

Finasteride + Minoxidil: Studies show that pairing topical finasteride with 5% minoxidil yields superior hair density and patient satisfaction compared to either agent alone, particularly after 24 weeks of treatment.^[14]Apoorva, V.B., Vibhu, M., Singh, R.H., Smita, T. (2023). Comparative Efficacy of Topical Finasteride (0.25%) in Combination with Minoxidil (5%) Against 5% Minoxidil or 0.25% Finasteride Alone in Male … Continue reading,^[15]Rossi, A., Caro, G. (2023). Efficacy of the association of topical minoxidil and topical finasteride compared to their use in monotherapy in men with androgenetic alopecia: A prospective, randomized, … Continue reading,^[16]Abeck, F., Hansen, I., Kott, J., Schroder, F., Garrahy, E., Veneroso, J., Runger, A., Torster, L., Schneider, S.W., von Buren, J. (2024). Patient-reported outcomes of topical finasteride/minoxidil … Continue reading This combination is effective for both new users and those who have experienced shedding after discontinuing oral finasteride.

Finasteride + Microneedling: Adding microneedling to topical therapy can significantly enhance outcomes. Clinical trials demonstrated that combining microneedling with minoxidil and/or finasteride increased hair density and shaft diameter more than minoxidil alone, with effects noticeable within just 12 weeks.^[18]Chang, Y., Zhang, W., Zhou, J., Lv, L., He, Q., Chen, Y., Wang, P., Zhai, Q. (2025). Clinical efficacy of microneedle combined with 5% Minoxidil solution and finasteride in the treatment of … Continue reading,^[19]Adistri, K., Sirait, S.P., Rihatmadja, R., Legiawati, L., Indriatmi, W., Saldi, S.R.F. (2024). Effectiveness and safety of the combination therapy of micro-needling and minoxidil in androgenetic … Continue reading 

Triple Topical Therapy: Preliminary studies on formulations that combine finasteride, dutasteride, and minoxidil show promising results, with visible regrowth as early as three months in some cases.^[20]Rafi, A.W., Katz, R.M. (2011). Pilot Study of 15 Patients Receiving a New Treatment Regimen for Androgenic Alopecia: The Effects of Atopy on AGA. ISRN Dermatology. 241953. Available at: … Continue reading

So, combination therapy appears to be more effective than monotherapy. Therefore, leveraging two or more topical therapies or adding microneedling can support hair regrowth outcomes.

Who Should (or Shouldn’t) Use Topical Finasteride?

Good Candidates:

• Men diagnosed with AGA.
• Those who tolerate oral finasteride but seek to minimize systemic risks.

Not Ideal For: 

• People with hair loss from causes other than AGA (e.g., alopecia areata, telogen effluvium). 
• Those who have previously shown a poor response to finasteride.
• Anyone trying to conceive, or with infants, toddlers, or pregnant individuals in close contact.
• Users who are unable or unwilling to follow consistent application routines or medical monitoring. 

Final Verdict

Topical finasteride is a legitimate option for hair regrowth. When formulated and used properly, it can rival oral finasteride’s effectiveness with a lower risk of systemic side effects. Success hinges on the right delivery method, correct dilution, and consistent application. While not flawless, it excels as part of a comprehensive regimen, especially when paired with therapies like minoxidil or microneedling. 

For those hesitant about oral medication, topical finasteride offers a practical, lower-risk compromise, provided users carefully follow evidence-based protocols to optimize both safety and results. Used strategically, it is a potent addition to hair loss treatment plans.