Some glucosamine supplements are stronger and more potent than others. Some users will find that this gives them stomach issues. If you have a sensitive stomach and the glucosamine supplements you are taking are a higher dosage, taking them with food can help ease your gastrointestinal issues. Other individauls, no matter the potency or strength of the dose, may experience minor bloating, gas, constipation, and/or stomach pain. Again, taking glucosamine along with your pre-workout meal or breakfast may help calm some of these issues. And as always, be sure to read the directions on your glucosamine bottle or packaging before starting a regimen.