What will i normally feel after a few days on paxil (paroxetine) 12.5 mg?

Hopefully nothing: All ssri antidepressants, including Paxil (paroxetine), take a few weeks to work. It would be quite unusual for Paxil to help mood or anxiety after only a few days. Side-effects are possible immediately, but are usually absent or mild on this fairly low dose. Most commonly: sedation, dry mouth, constipation. Talk to your doctor if any of these bother you.