TomTeleRx said:

The escalation order that reflects the mechanism: water and salt first, then soluble fiber, then magnesium or an osmotic agent, then a stimulant only…

Acid reflux and constipation: I developed GERD symptoms around week 6 that I'd never had before. The delayed gastric emptying means food and acid sit in your stomach longer.

Management that works for me: elevate head of bed 6 inches, don't eat within 3 hours of lying down, avoid trigger foods (tomato, citrus, spicy, chocolate), and famotidine 20mg at bedtime. Much better now.

A narrower follow-up, since the general answer is now clear:

Whether fiber actually helps GLP-1 constipation or whether the evidence is borrowed from a different population?

raj_cambridge said:

Acid reflux and constipation: I developed GERD symptoms around week 6 that I'd never had before.

Drug interaction alert relevant to constipation: if you take oral levothyroxine (Synthroid), GLP-1 agonists can reduce absorption due to delayed gastric emptying. My TSH drifted up after starting semaglutide.

Solution: take levothyroxine on an empty stomach, 60 minutes before any food, and have your TSH rechecked 6-8 weeks after starting or changing GLP-1 dose. My endo had to increase my Synthroid by 12.5mcg.

Reporting back.

Update — the osmotic agent was the thing. I had been reaching for a stimulant, which was making the next day worse.

Dr.NateNeph said:

Drug interaction alert relevant to constipation: if you take oral levothyroxine (Synthroid), GLP-1 agonists can reduce absorption due to delayed…

Gastroparesis symptoms with constipation: the delayed gastric emptying from GLP-1 agonists can cause early satiety, bloating, and feeling "full" for hours after a small meal.

Tips: eat your protein FIRST (most important macro), then vegetables, then carbs last. Chew thoroughly — 20-30 chews per bite isn't excessive. Avoid carbonated beverages with meals. If symptoms are severe, your doctor may recommend a gastric emptying study.