@etawon2024
I take different manufacturers of magnesium.
One is NatureMade Magnesium Citrate 250 mg. It takes two tablets to reach this 250 mg. I looked at back of bottle and per 2 pill serving it states Magnesium Citrate 250 mg. which is 60% of daily value. I take two of these daily.
Two: LIfe Extension: I augment the NatureMade magesium citrate to get my 400 by taking Life Extension Magnesium Citrate. It comes in 1 tablet for 100 mg of magnesium. I take two of these a day. They are 100 mg of magnesium in each tablet per bottle.

Heart Calm. You will read a lot about this product. I did research it and the form of Magnesium it contains is Taurate, Glycinate and Malate. It takes 3 capsules to reach 300 mg of magnesium. I do have this product but it also contains Taurine and Co-Q-10. I take Taurine and Ubiquinol (higher form of Co-Q-10) as separte supplements so the heartcalm is not my main source of magnesium. It do take the heart calm routinely but will reduce the Health Extension amount to stay close to the 400 mg. recommended for me.

My Mayo EP suggested the citrate based on his research and what was best for me. My EP stated many forms of magnesium and what may work better for one person but not the next. It is why citrate was reommended by him as it (research wise) as it is usuallly a very easy absorb form of magnesium.

About a month ago I did change from a magnesium, calcium, zinc combination tablet to the citrate because the combination tablet did not use citrate. For me, and must emphasize for me, I experienced a dramatic reduction in my PVCs. This was confirmed by my holter montior test as well as my ICD/Pacemker monitoring remote device. So the citrate is working for me and that is what I can pass on to you a personal experience for me and what my EP recommened I try.