What is causing shedding at the 1 year mark of Finasteride use?

Dear travis97,
To have this properly evaluated and to understand why you are having hair loss now you need to see a hair restoration surgeon.  They will be able to take a thorough history and do a proper examination to help understand what is happening.  If it is indeed further hair loss there are other things that can be used to help in addition to the finasteride.  PRP's (platelet rich plasma) injections and LLLT (low level laser therapy) have been shown to be very effective at preventing further hair loss.  
Sincerely,
Daniel Lee, MD, FACS

This needs an in-person evaluation. I suggest seeing a hair loss expert now to evaluate and go over your condition and provide you information about your best treatment options. There are great non-invasive options like prp/progesterone and/or hair transplantation. See an expert. Best, Dr. Emer

Finasteride here is unlikely the culprit. You’ll want to see your physician so he or she can review the story in full and examine your scalp. It’s possible your male balding is pushing forward and you need other treatments too added to the Finasteride. It’s also possible another completely different condition has entered the picture. It’s also possible this is within the realm of normal and nothing further needs to be done at the present time.

Normally everyone sheds between 50 - 150 hairs daily. Keep doing what you're doing. You should have a yearly examination with your doctor.

There is no guarantee that finasteride will continue to be effective. Hopefully, your doctor established a baseline for hair bulk with the HAIRCHECK instrument which should be repeated every year to establish the effectiveness or lack of effectiveness of the drug finasteride