Dutasteride inhibits both Type 1 and Type 2 5-alpha reductase, producing 99% DHT reduction at the scalp. Finasteride blocks only Type 2, achieving roughly 70%. Tracking your personal density response to each drug on the same scalp is the only way to determine which one works better for you.
The Core Pharmacological Difference
| Property | Finasteride | Dutasteride |
|---|---|---|
| Enzyme target | Type 2 only | Type 1 and Type 2 |
| DHT reduction | ~70% | ~99% |
| Standard dose | 1mg daily | 0.5mg daily |
| FDA-approved for hair loss | Yes | No (off-label use) |
| Half-life | 6 to 8 hours | ~5 weeks |
| Efficacy (halt loss) | 80 to 90% | Higher than Finasteride |
| Regrowth rate | 65% of users | Higher in clinical trials |
| Side effect rate | 2 to 4% | Higher than Finasteride |
These numbers represent population averages. Your individual response may differ significantly, which is exactly why personal tracking matters.
Why Population Data Is Not Enough
Clinical trials report that Dutasteride outperforms Finasteride in head-to-head comparisons for hair count increases. But those studies report mean results across hundreds of participants. Some individuals respond better to Finasteride. Others see dramatic improvement only on Dutasteride.
Your scalp is not an average. The only way to know which drug works better for your specific follicle sensitivity, enzyme distribution, and genetic profile is to track your personal data over time.
Setting Up a Treatment Comparison
If you are considering a switch from Finasteride to Dutasteride, structure your tracking as follows:
Phase 1: Finasteride baseline (months 1 to 12). Take monthly density scans while on Finasteride. After 12 months, you have a clear picture of what Finasteride does for your hair. If density stabilized but did not improve, Finasteride is working partially but may not be your optimal treatment.
Phase 2: Transition (week 1 to 2). Discuss the switch with your prescriber. Some doctors recommend a direct switch with no washout period, since Dutasteride covers all the enzyme targets that Finasteride was already blocking. Others prefer a brief overlap. Follow your prescriber's protocol.
Phase 3: Dutasteride tracking (months 1 to 12). Resume the same monthly scan schedule. Use identical conditions for every scan. The key comparison point arrives at month 6 on Dutasteride, where you compare the Dutasteride density curve against the Finasteride density curve from the same calendar interval.
Reading Your Comparison Data
Three outcomes are possible from a tracked treatment switch:
Clear Dutasteride advantage. Density increases 10 to 15% or more above your Finasteride plateau within 6 months. Side effects are tolerable. This confirms Dutasteride is the better option for your specific pattern.
Marginal difference. Density improves 0 to 5% above the Finasteride plateau. This small gain may not justify the higher side effect risk and the longer clearance time if discontinuation is needed. Discuss with your prescriber whether the improvement warrants continuing.
No improvement or regression. Density does not change or worsens after switching. This is rare but possible, particularly if your hair loss has a significant non-androgenic component. Your tracking data gives your prescriber the evidence to explore alternative causes.
Side Effect Comparison During the Switch
Log side effects throughout both treatment periods using the same severity scale. Key differences to watch for:
Finasteride side effects appear within 1 to 4 weeks and resolve within days of discontinuation. Dutasteride side effects may take 2 to 6 weeks to appear and, because of the 5-week half-life, can persist for months after stopping.
If you experienced no side effects on Finasteride, you may still experience them on Dutasteride. The 99% DHT suppression affects hormonal balance more aggressively than Finasteride's 70%. Track everything.
The Cost of Not Tracking
Without density data from both treatment periods, you are guessing. A prescriber has no objective evidence to compare. You may stay on a less effective drug for years or switch unnecessarily to a drug with more side effects.
Tracking removes the guesswork. Two clearly labeled treatment periods on the same scalp, measured under identical conditions, produce a personal clinical comparison that no published study can replicate.
Compare Your Treatments with Data
Start tracking your current treatment response at myhairline.ai/analyze. Whether you are on Finasteride now or considering Dutasteride, a density baseline today is the first step toward a data-driven treatment decision.
Medical disclaimer: This article is for informational purposes only. Do not switch medications without consulting your prescribing physician. Dutasteride is not FDA-approved for hair loss treatment.