I've been taking anti-depressants since the early 90s, but more seriously since I was hospitalized for depression with suicidal ideation in 1997. I've taken almost every anti-depressant on the market, and been through a vicious underworld of side effects. Cymbalta, for me, was like finally finding the light. I feel almost normal now.
I started with the 30 mg dose (it comes in capsules) but after about 9 months, had to increase the dose to 60 mg, the highest recommended dose. Cymbalta is an "SNRI" or a serotonin-neurontin re-uptake inhibitor. It works differently than most other antidepressants on the market (such as MAOIs, tricylics, and SSRIs). One of the things that really makes it different is that it doesn't make me drowsy. It can make some patients drowsy, but low doses are often prescribed for people with chronic fatigue or fibromyalgia to increase their energy levels.
It's also supposed to be weight-neutral; many antidepressants on the market cause weight gain (Remeron, Effexor, Paxil) but Cymbalta isn't supposed to. I didn't experience weight gain on the 30 mg dose, but I am on the 60 mg dose (although to be fair, I'm also taking prednisone for lupus, so that may be playing a role in the weight!). It isn't supposed to affect your mood in any way except improving it, or making it normal; with Paxil, for example, I found myself getting really cranky. I have to say, I don't need a pill to be cranky. I can do that all by myself!
For me, it hasn't caused headaches, drowsiness, dizzyness, or any muscle weakness, all symptoms I've experienced with other antidepressants. While I very much hope that no one reading this needs an antidepressant, if you feel sad all the time, and think about ending your life, GET HELP. You CAN feel better. Cymbalta has been a life-saver for me. I hope it continues to work.