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Before any supplement: more fluids, more fiber-rich food, and daily movement. On a GLP-1 you are usually eating and drinking less, so those three fix most cases on their own. The products below are the common next step when the basics are not enough — cheap, over-the-counter, and worth understanding before you buy.
Want the full method first? Read the GLP-1 constipation relief guide.
At a glance
| Option | Best for |
|---|---|
| Magnesium glycinate Gentle, well-tolerated form | A magnesium form often chosen because it tends to be gentle on the stomach. |
| Magnesium citrate (powder or liquid) Stronger, faster option | A more laxative-leaning magnesium form, often used as a drink mix. |
| Psyllium husk fiber Bulk-forming fiber | A soluble fiber supplement that adds bulk and softness to stool. |
| Fiber gummies Easiest format | A chewable fiber option for people who won’t keep up with powder. |
| Stool softener (docusate) Short-term relief | An over-the-counter stool softener for occasional, stubborn days. |
The common options, honestly
Magnesium glycinate
Magnesium supports normal bowel function and is a common first supplement people reach for. Glycinate is popular for being less likely to cause the urgency some other forms do.
Worth knowing: Magnesium is cleared by the kidneys — if you have kidney disease, check with your prescriber first. Start low; too much magnesium causes loose stools.
Magnesium citrate (powder or liquid)
Citrate draws water into the gut, so it tends to work faster and harder than glycinate. Useful when things are genuinely stuck rather than just sluggish.
Worth knowing: Easy to overshoot into cramping or diarrhea. Same kidney caution as above. Not for daily long-term use without guidance.
Psyllium husk fiber
Fiber is foundational for regularity, and appetite is low on a GLP-1, so food fiber often drops. Psyllium is one of the most-studied fiber supplements.
Worth knowing: Take it with plenty of water — fiber without enough fluid can make constipation worse. Add it in gradually to limit gas and bloating.
Fiber gummies
The best fiber is the one you’ll actually take. Gummies remove the mixing-and-gritty-texture barrier, which matters when nausea already makes things unappealing.
Worth knowing: Usually less fiber per serving than psyllium, and some contain added sugar or sugar alcohols that can upset a sensitive stomach. Check the label.
Stool softener (docusate)
When stool is hard and uncomfortable, a softener can help in the short term while the fiber-fluid-movement basics catch up.
Worth knowing: Meant for occasional use, not a daily fix. If you need something regularly, that’s a conversation with your prescriber, not a standing habit.
How to actually use these
Layer them, do not stack them all at once. Most people do best starting with fluids, food fiber, and walking, then adding one supplement — usually magnesium or a fiber supplement — and giving it a few days before changing anything. A stool softener is an occasional tool, not a daily plan. If you find yourself needing something every day to go, that is the signal to talk to your prescriber about dose timing or other options.
Buying vegan? Magnesium supplements are frequently in gelatin capsules. If that matters to you, Future Kind makes vegan-formulated magnesium — worth comparing on the same criteria as the picks above (affiliate link; we have not tested it, and it is not ranked above them).
Related: our guides to electrolytes on a GLP-1 (hydration overlaps with this) and the full side-effects playbook.
Frequently asked questions
Why does a GLP-1 cause constipation?
GLP-1 medications slow how fast the stomach and gut move, and appetite drops, so you often eat and drink less. Less food, less fiber, and less fluid together make stool harder and slower. It is one of the most commonly reported side effects.
What should I try before supplements?
Fluids, fiber-rich food, and daily movement are the foundation and cost nothing. Because intake is often low on a GLP-1, deliberately drinking more and walking regularly does a lot of the work. Supplements are an add-on when the basics are not enough.
Is magnesium safe to take every day?
Many people use magnesium regularly, but it is cleared by the kidneys, so anyone with kidney disease should check with a prescriber first, and everyone should avoid overdoing it (too much causes loose stools and cramping). This page is educational, not a personal recommendation.
When should I call my prescriber instead?
No bowel movement for several days, severe abdominal pain, vomiting, or blood in the stool are reasons to contact your prescriber rather than reaching for another supplement. Constipation that will not respond to the basics also deserves a real conversation.
Sources & further reading
This article draws on peer-reviewed research, official health-agency information, and other sources identified below. Source type and relevance vary; some links provide background rather than direct evidence for a product recommendation.
- 1.Constipation — overview and self-care — MedlinePlus (NIH)
- 2.Magnesium — Fact Sheet for Health Professionals — NIH Office of Dietary Supplements