Constipation

Constipation is, after nausea, the most common gastrointestinal side effect of GLP-1 medications — reported by a notable share of participants across the semaglutide and tirzepatide trials. It’s rarely dangerous, but it’s genuinely uncomfortable and, happily, one of the more fixable side effects.

Why it happens

A few of the medication’s effects line up against you:

• Slower digestion moves everything through more slowly, including through the intestines.
• Eating much less means less fiber and less food volume to keep things moving.
• Drinking less — blunted thirst leads to mild dehydration, and hard, dry stool.

In other words, the same appetite suppression that’s doing the work also quietly sets up constipation.

What helps

• Fiber, deliberately. A shrunken diet is a low-fiber diet by default. Prioritize vegetables, fruit, and whole grains where appetite allows, and a psyllium supplement is a reasonable tool — always with plenty of water, or it backfires.
• Fluids, on a schedule rather than on thirst.
• Movement. Even a daily walk helps intestinal motility.
• Over-the-counter options — a stool softener or gentle osmotic laxative (like polyethylene glycol) helps many people; ask your pharmacist about what fits you.

When to escalate

Constipation that becomes severe — no bowel movement for several days, with significant pain, bloating, vomiting, or a hard distended abdomen — is worth a prompt call, since bowel obstruction, while uncommon, is a serious concern with slowed motility. For the everyday version, though, fiber + fluids + movement resolves most cases.