TLDR Finasteride worsens alcohol withdrawal in female mice but eases it in male mice.
The study investigated the effects of finasteride on acute ethanol withdrawal severity in male and female C57BL/6J and DBA/2J mice. Finasteride, a 5α-reductase inhibitor, was found to increase withdrawal severity in female mice but decrease it in male mice, without altering blood ethanol concentrations, ethanol clearance, estradiol, or corticosterone levels. These results suggested sex differences in sensitivity to changes in neurosteroid levels, such as allopregnanolone, during ethanol withdrawal.
21 citations
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June 2005 in “Alcoholism: Clinical and Experimental Research” Finasteride reduces alcohol withdrawal severity and anxiety in mice, but may increase withdrawal severity in some cases.
134 citations
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February 2005 in “Neuropsychopharmacology” GABRA2 gene variations impact alcohol response, and hair loss medication finasteride reduces some effects.
26 citations
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August 2004 in “Alcoholism Clinical and Experimental Research” 
29 citations
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June 2004 in “Pharmacology, Biochemistry and Behavior” Finasteride reduces alcohol withdrawal effects, especially in female mice.
83 citations
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January 2004 in “Pharmacology & Therapeutics” 136 citations
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January 2004 in “Neuroscience” 
47 citations
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November 2002 in “Journal of Neurochemistry” Progesterone boosts alcohol's effect on brain, finasteride counters it.
269 citations
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May 2002 in “Journal of Neuroscience” 
60 citations
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December 1998 in “Clinical Pharmacology & Therapeutics” Both drugs lower DHT levels, with GI198745 being more effective.
98 citations
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April 1997 in “The Journal of Steroid Biochemistry and Molecular Biology” Finasteride effectively blocks rat enzymes, but with varying methods and strength.
19 citations
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March 2019 in “Behavioural Brain Research” Finasteride use can cause depression-like behavior in male rats.
35 citations
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May 2008 in “Drug and Alcohol Dependence” 
54 citations
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August 2005 in “Alcohol” Finasteride affects alcohol intake in male mice, possibly due to neurosteroids.
