Hi Patro,
The standard dose for Finasteride for hair loss is 1mg per day. Most users will use this, however there are a number of patients who go for a 0.5mg dose. If you are concerned about side effects, its best to closely monitor for the first 3 or so months. I personally took a blood test to have a record of my biology before starting Finasteride.
Keep in mind that although the side effects can seem scary, most patients are usually fine on the drug. Secondly, the clinical data showed that those few patients who did experience side effects returned back to pre-finasteride status once they stopped the drug.