I didn't take Effexor XL, but I did take Effexor XR. I experienced side effects while I was on it and withdrawal symptoms that lasted for 6 months. My side effects/withdrawal symptoms included: brain zaps, extreme sweating, dizziness, dry mouth, fatigue, major headaches, nervousness, vertigo, and confusion. When I started taking it, I lost 20 pounds in 2 weeks! I was wanting to lose weight, but in a healthy way. My advice to you is get off of it asap.