Finasteride and Ketoconazole Interaction

Synergistic
Researched 95% confidence

Finasteride and Ketoconazole have a synergistic interaction with 95% confidence. Core combination in the "big 3" hair loss stack. Finasteride reduces systemic and scalp DHT production via 5-alpha reductase inhibition, while ketoconazole disrupts DHT binding locally at the follicle and reduces scalp inflammation. The two target hair loss through complementary mechanisms. Both compounds affect the skin, so monitoring these systems is recommended.

Compound Profiles

Finasteride

5-Alpha Reductase Inhibitor | DHT Blocker for Hair Loss & BPH

Finasteride competitively and selectively inhibits the Type II isoform of the enzyme 5-alpha reductase, which is predominantly found in hair follicles, the prostate, and the liver. This enzyme converts testosterone into dihydrotestosterone (DHT).

Half-life: 6-8 hours (DHT suppression persists ~24 hours) Typical dose: 1mg/day (hair loss) or 5mg/day (BPH) hair loss
5 alpha reductase estrogenichepatotoxicteratogenic
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Ketoconazole

Antifungal | Topical Anti-Androgen for Hair Loss

Ketoconazole works through multiple pathways relevant to hair loss. As an azole antifungal, it inhibits the enzyme lanosterol 14-alpha-demethylase, disrupting ergosterol synthesis and killing Malassezia fungi that colonize the scalp and contribute to inflammation and seborrheic dermatitis.

Half-life: Topical application stays local with minimal systemic absorption Typical dose: 1-2% shampoo hair loss
androgenic
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Combined Organ Load

Skin
low

Frequently Asked Questions

Can I take Finasteride with Ketoconazole?

Yes, Finasteride and Ketoconazole can generally be taken together. Core combination in the "big 3" hair loss stack. Finasteride reduces systemic and scalp DHT production via 5-alpha reductase inhibition, while ketoconazole disrupts DHT binding locally at the follicle and reduces scalp inflammation. The two target hair loss through complementary mechanisms.

Is Finasteride and Ketoconazole safe together?

Based on documented research, this combination is considered synergistic. No critical safety flags identified for this pair.

What are the interactions between Finasteride and Ketoconazole?

Core combination in the "big 3" hair loss stack. Finasteride reduces systemic and scalp DHT production via 5-alpha reductase inhibition, while ketoconazole disrupts DHT binding locally at the follicle and reduces scalp inflammation. The two target hair loss through complementary mechanisms. This assessment has 95% confidence and is based on documented research data.

How should I time Finasteride and Ketoconazole?

Finasteride has a half-life of 6-8 hours (DHT suppression persists ~24 hours) and Ketoconazole has a half-life of Topical application stays local with minimal systemic absorption. No specific timing requirements identified for this combination, but separating administration can help monitor individual effects.

Check this pair in the full Interaction Checker Full comparison: Finasteride vs Ketoconazole

This interaction analysis is compiled from research literature and pharmacological mechanism data. Always consult a healthcare professional before combining compounds.