Magnesium problem


So, I purchased the Now foods magnesium citrate that I’ve noticed a lot of people using. The package says that 1.9 g of the supplement contains 315 mg of magnesium, but that can’t be right because magnesium citrate is only 11% magnesium by mass. Has everyone else been going off of molar mass or the product labeling? Or is there something I’m not aware of? Now I’m concerned that my other source of magnesium (Whey protein Isolate by NOW Foods) is inaccurate as well. And the tolerance for magnesium is fairly slim.


German Wikipedia ( says Magnesium Citrate is Mg3(C6H5O7)2-9H2O
It is used to raise your body’s level of magnesium ions. It works as a weak laxative. It lowers the potential for neural and muscular irritation. Extreme overdoses paralyse the central neural system.

Clicking the “English” link on that specific page brings you to this english version (
Magnesium Citrate is C6H6MgO7
It is used as a laxative and to empty the bowel prior to surgeries.
The irritation potential stuff is not mentioned and the neural system stuff is not mentioned directly. Rectal bleeding is mentioned though.

The problem is probably not with Now foods, but that 2 different opinions about what Magnesium Nitrate is exist.

If in doubt, I would follow what it says on the package. NOW foods is a big enough brand to be controlled and everything. Hopefully. :smiley:


So, there are two different chemicals that go by the name Magnesium Citrate, and one has about 3 times as much magnesium? That explains a lot, but it probably also something that people should be aware of, considering the risk of magnesium overdose if you confuse one chemical for the other. Thanks.


That chemical should be referred to as “trimagnesium citrate”. So, I guess either NOW foods is selling trimagnesium citrate as magnesium citrate, or they are selling magnesium citrate that is labeled for trimagnesium citrate.


Magnesium supplementation is presenting me a dilemma.

From what I am reading, I am magnesium deficient, so I am supplementing with 100mg of Magnesium Citrate a day (Oxide is rubbish, avoid). I am the worrier/anxious type of person so I surely need supplementation.

However this is clearly not enough, when I dose up to 200mg of Magnesium I get “overdosed” and get diarrhea, dehydration and increase anxiety (DDA). So now I am switching to chelated magnesium, hoping I can increase the dose without getting the DDA side-effects.

Anyone using Magnesium Citrate (on its own or in the Soylent mix) had/having similar problems?


is it showing you 1.9 g =315mg magnesium on a recognizable supplement facts label? , percent daily values and all that? because that should be showing you the bioavailable amount per dose. You shouldn’t have to mess with molar mass unless your buying chemical grade stuff, the stated % of daily value is supposed to eflect what you will actually be consuming.


I have no doubt the labelling is correct, however 200mg of magnesium citrate were enough to dehydate me, give me diarrhea and make me anxious due to dehydration.

When I started to supplement magnesium I felt fantastic but then after a week this happened. I wonder if other people had similar experiences - this should not be a problem with Soylent which in version 8 uses magnesium gluconate.


I have made a set of blood tests and whilst my magnesium levels are within range (0.8mg/L), my ferritin levels are low 13 ng/ML (healthy range: 22 - 322) - I suspect that the magnesium intake has negatively affected my iron absorption to the point of causing the symptoms I mentioned above.


Take it two hours apart. When im giving iron supplements to patients thats what I do, anythibg with otherminerals (antacids and such) two hours apart from the iron.


So you recommend I take an iron supplement 2 hours before I take the magnesium? Are 2 hours enough to ensure the iron is absorbed?


It’ll be far enough along in your GI tract to not interfere and to be absorbed yes. I’m not a doctor but the 2 hours is the rule of thumb they taught me in nursing school. So, keep up with the blood tests but I think this should work.


I accidentally took too much magnesium for a couple of weeks last fall (500mg/day), it was weird, initially I got a really good mood then developed a facial twitch, like a twitchy grin on one side. It kept on for another two weeks after I figured out two 250mg pills a day was too much.

Kind of weirded out my co-workers for a while though.


I suffered from a twitch under my left eye and a weird numb feeling in my 4th foot toe and this with just 200mg of magnesium. What kind of magnesium did you take? Mine is magnesium citrate (100mg a pill).


Chvosteks sign. Hypocalcemia.


I have read somewhere that magnesium facilitates the absorption of calcium, but if the case in question is a question of mild hypocalcemia, then magnesium is interfering in the absorption of calcium.