L-Citrulline, L-Citrulline, L-Citrulline, L-Citrulline, L-Citrulline and pycnogenol - Sorry, I'm a little emphatic about it. Increases the NO and makes Cialis 100x more effective for me. I'm on 5mg Cialis daily (well almost daily, I forget a lot) with a spoonfull of L-Citrulline and pycnogenol...