Magnesium is involved in 300+ enzymatic reactions and is one of the most common nutrient deficiencies. GLP-1 users are at particular risk due to reduced food intake. This guide covers everything you need to know.
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Why magnesium matters on GLP-1s
Magnesium supports:
- Sleep — promotes relaxation, improves sleep quality
- Muscle function — prevents cramps, supports relaxation
- Digestion — osmotic laxative effect helps constipation
- Mood — deficiency linked to anxiety and depression
- Blood sugar — improves insulin sensitivity
- Blood pressure — helps regulate
- Bone health — works with calcium and vitamin D
- Migraine prevention — reduces frequency in some users
For GLP-1 users specifically, magnesium helps with:
- Constipation (especially magnesium citrate)
- Sleep disruption (common GLP-1 side effect)
- Muscle cramps (from new exercise or electrolyte shifts)
- Mood swings
- Fatigue (magnesium is needed for energy production)
Forms of magnesium
Magnesium glycinate (best all-around)
Most bioavailable form, gentle on stomach, supports sleep and relaxation. Best choice for daily supplementation.
Magnesium citrate
Well-absorbed, has laxative effect. Good for constipation but can cause diarrhea in higher doses.
Magnesium oxide
Poorly absorbed (only 4%). Often used in cheap supplements. Avoid.
Magnesium chloride (SlowMag)
Enteric-coated, gentler on stomach. Good for sensitive users. Slightly less bioavailable than glycinate.
Magnesium threonate
Crosses blood-brain barrier. May support cognitive function. More expensive.
Magnesium malate
Often used for fibromyalgia and chronic fatigue. May help with energy.
Best form for GLP-1 users
Magnesium glycinate for daily use (sleep, mood, muscle). Magnesium citrate if constipation is significant. Avoid oxide.
Our top picks
Designs for Health Magnesium Glycinate — 120 Capsules
Highly bioavailable magnesium glycinate — supports the muscle cramps, sleep disruption, and constipation that GLP-1 users frequently report.
$25–32Check Price on Amazon
SlowMag Mg Muscle + Heart — Magnesium Chloride with Calcium, 60 Tablets
Enteric-coated magnesium chloride that's gentler on the stomach than other forms. Particularly good for GLP-1 users with sensitive digestion who still want magnesium's muscle and sleep benefits.
$14–18Check Price on Amazon
Why Designs for Health Magnesium Glycinate
- Highly bioavailable form
- Patented Albion TRAACS form
- Buffered for gentle digestion
- 120 capsules (4-month supply)
- Vegan, gluten-free
- Trusted practitioner brand
Why SlowMag for sensitive stomachs
- Enteric-coated (gentle on stomach)
- Magnesium chloride + calcium
- Particularly good for GLP-1 users with sensitive GI
- More affordable than Designs for Health
How to take magnesium
Dose
- Men: 400-420mg daily
- Women: 310-320mg daily
- GLP-1 users (higher need): 400-600mg daily
- For constipation: 400-800mg magnesium citrate at bedtime
Timing
- At bedtime: Best for sleep support
- With food: Improves absorption, reduces stomach upset
- Avoid with calcium — calcium competes for absorption
- 2 hours apart from medications — magnesium can interfere with absorption
Starting protocol
- Start with 200mg daily for first week
- Increase to 400mg in week 2
- Adjust based on response (sleep, digestion, mood)
- Don't exceed 600mg without provider guidance
Food sources
Food sources are ideal but most GLP-1 users need supplementation too:
High-magnesium foods
- Pumpkin seeds — 156mg per oz (highest)
- Spinach (cooked) — 157mg per cup
- Swiss chard (cooked) — 150mg per cup
- Black beans — 120mg per cup
- Quinoa — 118mg per cup
- Almonds — 80mg per oz
- Cashews — 74mg per oz
- Dark chocolate (70%+) — 64mg per square
- Avocado — 39mg per half
- Banana — 32mg each
Calcium and magnesium compete for absorption. If you take calcium, take it at a different time than magnesium (e.g., calcium in morning, magnesium at bedtime).
FAQs
Can I take too much magnesium?
Excess magnesium from food is excreted safely. Excess from supplements can cause diarrhea, nausea, cramps. Very high doses (5,000+ mg) can be dangerous. Stick to 400-600mg daily from supplements.
Should I take magnesium citrate or glycinate?
Glycinate for daily use (sleep, mood, muscle). Citrate if constipation is your main concern. Don't take citrate daily long-term without provider guidance.