Here's my experience. I was only on it for a few weeks, but the side effects were intolerable, they were getting worse, and there were just too many of them. It seems that side effects and withdrawal problems from duloxetine are common enough that it should be approached with great caution. I was on it for pain rather than depression.
Effect on pain - possibly reduced it, hard to tell as it fluctuates so much, and I certainly had a couple of bad pain days.
Feeling like a zombie - head all foggy, exhausted, much lower activity levels (i.e. dropped suddenly to being bedbound, previously I was able to get out regularly), dizzy. This was one of the worst things. I've been off it two days and the difference is unbelievable - and that's after taking three tramadol!
Nausea - this was pretty unpleasant and made it difficult to eat.
Pain tolerance dropped - this could have been due to the effect where I couldn't handle much physical contact, but when I managed to drag myself out for myofascial release and trigger point therapy (which really helps with pain for me), narrowly avoiding collapsing despite getting a taxi door to door, I couldn't handle much and kept on having to tell the therapist to stop when she'd barely got into a trigger point. It was a weird restless, wriggly, generally uncomfortable feeling.
Stomach pain - on and off.
Diarrhoea on the higher dose, constipation on the lower dose (I didn't get past 40mg).
Frequent urination - hourly or more often. This was one of the dealbreakers, as I was going to the toilet all night.
Jerking body movements - possibly a Restless Legs Syndrome flare-up, although it was affecting more of my body than my legs, something I've not experienced in years. Not too often, but very unpleasant, especially when trying to sleep.
Off sex and physical contact, feeling disconnected - this was another dealbreaker, as I'm in a relationship. Sex is important to me, as is having a lot of physical contact with my partner. I couldn't even cope with much kissing or touching, I kept on feeling jittery from gentle forms of contact. This is a horrible thing to go through when you're in a loving relationship, and long-term would have been very damaging to my sense of self and especially to the relationship.
Breathlessness and chest pain - that affected functioning quite a lot. I normally get a bit of breathlessness in the mornings, but it was greatly increased.
Teeth chattering - only slight, but another sign that this was not a good med for me.
Withdrawal: I've only been off it a few days, but so far the only problem is lots of very vivid dreams and nightmares, waking up from them drenched in sweat. Again, this seems to be a known duloxetine withdrawal problem. Thankfully I wasn't on it long enough to get serious withdrawal.
I was meant to go up to 60mg eventually, at which point presumably all of this would have been even worse.
