Can I take Finasteride 1mg for lifetime regarding male pattern baldness? Can it cause any side effects?

Fenasteride can be used for long years, however it is better to do this with breaks. if you use it for a year than i would recommend to take a break for 2 months. other than that if you are planning on using it for a long time, get your hormonal checks done regularly 

All treatments for male balding are life long so in this regard there is nothing too different about finasteride. Finasteride has been available to the public for about 25 years.  Certainly you will want to speak with your physician again and pharmacist about all the potential side effects as anyone starting any new medication no matter what it is needs to be aware of all the risks and benefits. Side effects of finasteride include mood changes, depression, sexual dysfunction (decreased libido, impotence, and ejaculatory disorders), gynecomastia. Take the time to understand the risks and benefits of the medication so you can ultimately decide if it is right for you.

Assuming that you don’t have side effects, you can take finasteride for life. It’s value reduces as you get older and your testosterone naturally drops.  This drug is used in older men for an enlarged prostate