Q: I’ve heard that using Propecia and/or Rogaine is a good idea after having a hair transplant, but are they mandatory? — B.M., Short Hill, N.J.

A: Neither finasteride (brand name: Propecia) nor minoxidil (brand name: Rogaine) will have any effect on transplanted hair. That said, while you don’t need them to protect your transplanted hair, you will likely have original hair interspersed among your transplanted hair that will continue to thin and fall out over time. This vulnerable hair can be protected by finasteride which has been shown to reduce future hair loss significantly; additionally, you can add Rogaine for extra benefit.

However, with Propecia, you should only use it if you can commit to it long-term because it takes up to a full year to see any effect. With Rogaine, you should only use it if you can commit to using it continually and regularly – you should not stop and start it.