Transaction Log file growing hugely in Full recovery model although a regular log backup in place

Hello, 

One of my database is 46 GB and running on Full recovery model.

There is a transaction log backup in place which runs every 15 minutes. 

I've seen the transaction log file increases up to 8 GB every other day. I then manually have to shrink the transaction log file to release the unused space. 

I'm quite tempted to put a job in place to run the DBCC Shrink command everyday, however I've read on few of the forums that running DBCC Shrink regularly for a transaction log file is not recommended and could damage it. 

Any suggestion on this or any alternative solution?

Best regards, 

MC