I'm taking tirzepatide, and yup, nausea and constipation. Gets worse every time I titrate up, so I did increased dosage about half as fast as the clinical trials tested, never got to max dose available, stopped at my goal, and have just started dropping down to find a maintenance dose. In my case, the impacts are clearly dose-dependent.

I'm prone to constipation, and I'll second the 250 mg ducosate recommendation. Also occasional miralax. I've also got a recipe for a home-made product made with dried fruit and senna tea I picked up from a friend with Parkinson's. And I'm largely done with white flour and refined grains, because I need the fiber from groats and whole grain flour.

My primary care physician gave me a nausea prescription for ondansetron, which I use when it is really important to me to not abandon a meal a dozen bites in, such as going out to eat with friends and family. It works quite well. Beyond that, I've got an odd vagus nerve behavior -- I know when to stop trying to power through when I start sneezing. Fortunately, there is negligible delay between triggering food and symptoms, so I've learned pretty quickly which foods are more benign for me than others. (These may not be logical. Most of the time, I can't do soft grain products like bread and pancakes, but I can do toast and crackers. I can do broccoli most of the time, but brussels sprouts only when I'm feeling particularly symptom-free. Trust your own gut.)

I've learned to prioritize protein early in the meal, since these drugs are known for muscle mass impact. I'm also taking a bariatric multi-vitamin.

Apparently some people find that if they switch between GLP-1 RAs, that helps -- they have fewer side effects with some than others. That's my fallback, although I'm not there yet.