Does L-arginine work to cure ED only in the short term ?

I have been using a Mix of L-arginine ( 5g a day) , Maca and Ginkgo Biloba to improve my libido and erections.
The first 3 months, I saw a very strong improvent in my libido and erections.
However, after these months i noticed that my body developed a tolerance to these herbs, it simply didnt work anymore and i stopped using them, i haven't used them for 2 months now.

Is there anybody who has experience with L-arginine usage on the long term, and is there a way to prevent our body from developing a tolerance to L-arginine ?