It took me a while to put two and two together since I dont use it too often but I'll be damned if everytime I took Viagra I got a wicked migrain. I tried Cialis and it was the same shit! Personally, I find taking Unleashed along with a double dose of "Post-Cycle" gives the same effect as 50 mgs of Viagra. In fact, it's better since it raises libido as well. (And it's cheaper). Here's a tip: try taking 4 grams of Arginine along with it. Wow! And no headaches.