Any doctors here? Anti depressant help!

I am not a doctor, but I am fairly well-versed when it comes to psych meds (been on many and done lots of research).

Weight side effects (gain or loss) were not one of the common side effects from the Pristiq trials. Reduced appetite WAS one of the most common side effects, and you can deduce from that what you will. However, these trials typically last only 6-8 weeks and I'm not conversant in what effect Pristiq has on weight in the long term. That said, side effects wish anti-depressants usually make themselves known right at the beginning then lessen or stop entirely as the body adjusts, so how your body reacts initially will likely be a good indication.

Pristiq is the active metabolite of Effexor. What this means is that it's what you get after your body has already metabolised Effexor. Since side effects are often a by-product of the body metabolising a drug, one could postulate that there would be a reduced incidence of side effects with Pristiq when compared with Effexor. Effexor is generally more likely to make people gain rather than lose weight, though if had no effect on my weight.

Pristiq may cause you to gain or lose weight, or it may have no effect on your weight whatsoever. Everyone is different. Even if many people were to experience weight gain from Pristiq, it doesn't mean that you will. You will only know how it effects you once you start taking it. I would suggest keeping a closer tab on your weight when first starting any medication. You can always stop taking if under the advice of your doctor if you cannot or do not wish to tolerate any side effects. But DO NOT stop cold turkey unless under medical advice.

A salient point: you don't say why you have been prescribed Pristiq, but if it is for depression, bear in mind that weight gain or loss is a symptom of depression itself. So if depression has causes you to weight gain, you may well lose weight once it is adequately treated (and vice versa).

If you have concerns about the side effects of any medications you should talk to your prescribing doctor. It is YOUR health, and anything that anyone -- including myself! -- says here is no substitute for proper medical advice. Oh and I'm pretty sure if would be wrong for a doctor to give you medical advice over an Internet forum if they aren't actually your doctor and have not seen you in person. Just saying. :-)