Here are side effects from dutasteride done by a study i found.Adverse reactions reported over a 24 month period:
Month 0-6 (n = 2,167)
Impotence: 4.7%
Decreased libido: 3%
Ejaculation disorders: 1.4%
Breast disorders: 0.5%
Month 7-12 (n = 1,901)
Impotence: 1.4%
Decreased libido: 0.3%
Ejaculation disorders: 0.5%
Breast disorders: 1.1%
Month 13-18 (n = 1,725)
Impotence: 1%
Decreased libido: 0.1%
Ejaculation disorders: 0.4%
Breast disorders: 0.8%
Month 19-24 (n = 1,605)
Impotence: 0.8%
Decreased libido: 0.3%
Ejaculation disorders: 0.1%
Breast disorders: 0.6%
As you can see, a relatively low percentage of people experience side effects, and I would estimate there is a slightly higher probability of experiencing side effects from dut as opposed to fin.
