Topical finasteride delivers the same DHT-blocking effect as oral finasteride directly to the scalp while reducing systemic exposure by 50% or more. The standard formulation is a 0.1% solution applied once daily, and clinical data shows it produces similar hair regrowth to oral finasteride 1mg with fewer reported sexual side effects.
This article is for informational purposes only and does not constitute medical advice. Consult a physician before starting any medication.
How Topical Finasteride Works
Topical finasteride inhibits type II 5-alpha reductase in the scalp, reducing local DHT levels at the follicle. The key advantage over oral finasteride is the delivery route. When applied to the scalp, the drug concentrates in the target tissue while a smaller percentage enters systemic circulation.
Oral finasteride reduces serum DHT by 65 to 70%. Topical finasteride at the 0.1% concentration reduces serum DHT by approximately 25 to 35%. Both formulations achieve meaningful scalp DHT reduction, but the topical version exposes the rest of the body to significantly less of the drug.
Oral vs Topical: Key Metrics
| Metric | Oral Finasteride 1mg | Topical Finasteride 0.1% |
|---|---|---|
| Serum DHT reduction | 65 to 70% | 25 to 35% |
| Scalp DHT reduction | ~40% | ~30 to 40% |
| Hair count increase (24 weeks) | +11.8 hairs/cm2 | +12.7 hairs/cm2 |
| Sexual side effects | 3 to 5% | 1 to 2% |
| Administration | One pill daily | 1mL applied to scalp daily |
| Cost per month | $10 to $30 (generic) | $40 to $90 (compounded) |
Efficacy Data
The largest clinical comparison between topical and oral finasteride was a multicenter phase III trial with over 400 participants randomized to topical finasteride 0.1%, oral finasteride 1mg, or placebo.
Hair Count Results at 24 Weeks
| Group | Mean Change in Hair Count (per cm2) |
|---|---|
| Topical finasteride 0.1% | +12.7 |
| Oral finasteride 1mg | +11.8 |
| Placebo | -0.6 |
The difference between topical and oral finasteride was not statistically significant, meaning they performed comparably. Both were significantly better than placebo.
Patient satisfaction surveys within the trial showed similar results: approximately 70% of patients in both active treatment groups rated their improvement as moderate or better at 6 months.
How to Apply Topical Finasteride
Proper application is essential for results. The drug needs to reach the scalp, not sit on top of hair shafts.
Step-by-Step Application
- Start with dry or towel-dried hair (not wet)
- Part hair in the area of thinning or loss
- Draw 1mL of solution into the dropper
- Apply drops directly to the scalp along the parting
- Re-part hair and repeat until the full 1mL is distributed across the treatment area
- Massage gently with fingertips for 30 to 60 seconds
- Allow to air dry completely (15 to 20 minutes)
- Do not wash hair for at least 4 hours after application
Application Tips
| Tip | Why It Matters |
|---|---|
| Apply at bedtime | Allows maximum scalp contact time overnight |
| Use on dry hair | Wet hair dilutes the solution and reduces absorption |
| Focus on thinning areas | Drug works locally, not systemically from the scalp |
| Wash hands after applying | Prevents transfer to face or other skin |
| Do not use a hair dryer | Heat can degrade the active ingredient |
Some formulations combine topical finasteride with minoxidil in a single solution. These combination products simplify the routine from two separate applications to one.
Side Effects
The primary advantage of topical finasteride is the reduced side effect profile. Because less finasteride enters the bloodstream, the systemic effects are dampened.
Side Effect Rates
| Side Effect | Topical Finasteride | Oral Finasteride |
|---|---|---|
| Decreased libido | <1% | 1.8 to 3% |
| Erectile dysfunction | <1% | 1.3 to 3% |
| Scalp irritation | 2 to 5% | N/A |
| Scalp dryness or flaking | 1 to 3% | N/A |
Topical finasteride introduces a side effect that oral does not: local scalp irritation. This is typically caused by the vehicle (alcohol or propylene glycol base) rather than the finasteride itself. Switching to a different compounding pharmacy or formulation base often resolves this.
The reduced serum DHT suppression (25-35% vs 65-70%) is why sexual side effects are less common. However, it is important to note that some systemic absorption does occur. Topical finasteride is not zero-risk for sexual side effects. It simply lowers the probability.
Cost and Availability
Topical finasteride is not commercially available as a mass-produced pharmaceutical in most countries. Most patients obtain it through compounding pharmacies, telehealth hair loss platforms, or specialty clinics.
Cost Comparison
| Source | Monthly Cost |
|---|---|
| Compounding pharmacy (US) | $40 to $90 |
| Telehealth platform (Hims, Keeps, etc.) | $30 to $75 |
| Generic oral finasteride | $10 to $30 |
| DIY (crushing tablets into minoxidil) | Not recommended due to dosing inconsistency |
The price premium over oral finasteride is significant. Patients who tolerate oral finasteride well have no compelling reason to switch based on cost alone. The topical version is best suited for men who experienced side effects on oral finasteride or who want to minimize systemic exposure as a precaution. See our finasteride cost guide for a full pricing breakdown.
Who Should Consider Topical Finasteride
Good Candidates
- Men who experienced sexual side effects on oral finasteride
- Patients who want DHT suppression with lower systemic exposure
- Men starting treatment who are concerned about potential side effects
- Patients already using topical minoxidil who want a combined regimen
Not Ideal For
- Men who tolerate oral finasteride with no issues (unnecessary cost increase)
- Patients who want maximum DHT suppression (oral or dutasteride is stronger systemically)
- Anyone unwilling to commit to a daily scalp application routine
- Men with very short or shaved hairstyles (product can be visible on the scalp)
How It Fits Into a Treatment Plan
Topical finasteride occupies a middle ground between doing nothing and taking oral finasteride. It is appropriate at any Norwood stage where DHT suppression is warranted. Use our Norwood scale guide to identify your current stage and determine the level of intervention that makes sense.
For patients at Norwood 2 to 3, topical finasteride alone or combined with minoxidil may be sufficient. At Norwood 4 and beyond, most dermatologists recommend considering oral dutasteride or finasteride for stronger systemic DHT suppression, potentially combined with a hair transplant consultation.
Next Step
Upload a photo at myhairline.ai/analyze to get a personalized assessment of your hair loss stage and whether topical finasteride fits your treatment plan.