Magnesium (Glycinate)
Electrolyte that drops with GLP-1 GI side effects and high-dose injection cycles.
What it is
Essential mineral. Glycinate form is the most bioavailable and least likely to cause loose stools. Required for 300+ enzymatic reactions including ATP synthesis and nerve function.
Why peptide users take it
GLP-1 users on tirzepatide/retatrutide get diarrhea and reduced food intake; both deplete magnesium. Symptoms: muscle cramps, fatigue, poor sleep, irritability. Many users dismiss these as 'just the peptide' when it's actually correctable.
Pairs with these peptides
How it actually works
Magnesium gates the function of ATP, the cellular energy currency. Every ATP molecule has to bind a magnesium ion to be biologically active. It also blocks NMDA receptors (calming the nervous system, hence the sleep effect) and is a calcium-channel modulator (so it relaxes muscle). Low intracellular magnesium = high stress signaling, poor sleep, twitchy muscles, lousy energy.
Dose
When to take
Signs you actually need this
- Muscle cramps or eyelid twitches
- Poor sleep quality / waking at 3 AM
- Constipation that's not from the GLP-1 itself
- Irritability or low stress tolerance
- Headaches or migraines getting more frequent
Signs it's working
- Sleep deepens within 5–10 days
- Cramps resolve in the first 1–2 weeks
- Steadier mood under stress
- BMs become more regular if constipation was the issue
Common mistakes
- Buying magnesium oxide (cheap, ~4% absorbed, mostly causes diarrhea)
- Taking it in the morning, wastes the calming/sleep benefit
- Stacking with high-dose calcium at the same time, they compete
- Stopping at first sign of improvement, you're treating ongoing depletion, not a one-shot fix
Where to buy
Editorial picks. Brand selection follows the quality criteria (USP/NSF or third-party COA where possible). Affiliate links , see the disclosure at the bottom of /supplements.
Caveats
- Avoid magnesium oxide, poor absorption, mostly causes diarrhea.
- Don't stack with high-dose calcium at the same time; they compete.
Turn this peptide into a plan that's yours
The info above is free. Membership makes it personal, the Coach answers questions about your exact stack, the Stack tracks it for you, and the Sources desk shows you how to vet what you buy.
- ✓ AI Coach, ask anything about your stack. It does the dosing math, flags interactions, and tells you what to do next.
- ✓ Personal Stack, save your protocol, track it across devices, log doses, get a heads-up before a vial runs out.
- ✓ Sources desk, the vetted reference for checking quality and sourcing, members only.
Cancel anytime · or save with $80/yr · Coach + Stack included