Which formulation of magnesium? And how long (days/weeks) of supplementation before you noticed a difference? Does it 'wear off' once you stop?
Citrate causes me to have too soft of stools. Glycinate is often recommended for sleep, but for me it has the opposite effect – it wires me. I have tried taurine, malinate, and threonate, but chloride just works the best for me.
Electrolytes do ‘wear off’ in the sense that they are constantly depleted by your body, even when everything is working well. I have come up with the metaphor that electrolytes are like gas and oil in your car. They are constantly used up and need to be replenished. This is normal.
The good news is that I noticed the difference immediately!
https://www.sleepfoundation.org/magnesium
https://www.healthline.com/nutrition/magnesium-types#9-Magne...
Been doing this for a lot of years now.
Edit, here's a paper by some other researchers: https://www.tandfonline.com/doi/abs/10.1080/0963748012005760...
You basically need to be careful with any supplement since it's unregulated, and need to do a lot of careful diligence. It's a good sign if they are honest about their supplier and you trace back their supply chain. E.g. for many chelated supplements (zinc included), if you see a TRAACS trademark then the source is Balchem (Albion) which to my understanding is fairly well regarded.
ConsumerLabs tested one such TRAACS product and found it to be 0.1 mcg/g cadmium, so likely most products using TRAACS zinc bisglycinate formulation should be similar. I also found some EU food safety application [1] which confirms that across 3 different manufacturers of zinc bisglycinate (one of which is Albion), all samples were < 0.1mcg/g
[1] https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa....