My first post. I've been using magnesium oxide to prevent constipation. My understanding is that magnesium oxide has a poor absorption rate - and therefore excels as a laxative.

I'm attempting to 'fine tune' my magnesium regimen. My question: Is magnesium oxide a better laxative choice than magnesium chelate - which appears to have a higher absorption rate?

I guess I'm looking for the least absorbable magnesium which should equate as being the best magnesium laxative.

Comments appreciated ~ james

I'm wondering if there are better options for what you need.
There is a risk of over dosing on magnesium with heart problems a concern.
I take the chelate version for muscle tightness relief, but it is not cheap. It also has a laxative effect.
Have you considered some of the herbal laxatives, such as Herbalax?
I take this every day to compensate for pain tablets. Easy to vary the dose as required.
I wonder if it would be both cheaper and more reliably effective than fiddling around with an unknown supplement.

One gets about 8mg of magnesium from 400mg of magnesium oxide. This was done in studies.

from... http://www.ncbi.nlm.nih.gov/pubmed/11794633?ordinalpos=1&itool=EntrezSystem2.PEntrez. Pubmed.Pubmed_ResultsPanel.Pubmed_SingleItemSupl.P ubmed_Discovery_RA&linkpos=2&log$=relatedarticles& logdbfrom=pubmed

400mg of mag oxide has 200mg of elemental magnesium, so 4% of 200mg is 8mg.

So yes, for a laxative mag oxide will work. There is a product of magnesium designed as a laxative...Phillips Milk of Magnesia. It contains magnesium oxide.
http://phillipsrelief.com/caplets.html

Thanks Peter B and mrsD,

It was after trying MOM that I 'discovered' magnesium. After considerable trial-and-error, I ended up with a daily regimen of 800 mg of magnesium oxide and 750 mg of chelated magnesium {1050 mg total daily}. This combination provides near normal regularity when split morning/eve {as long as I drink copious amounts of liquid}.

My desire to fine-tune {minimize my daily magnesium intake for the long haul}, has led me to consider replacing the 750 mg of chelated magnesium with less regular magnesium oxide - since it appears to be the least absorbed of all the magnesiums - and therefore functions best as a laxative.

I've been taking 1050 mg for over a year - and all seems well. I was just wondering about replacing the chelated magnesium with magnesium. Then, I read about magnesium citrate . . . {so many different kinds of magnesium out there}.

Thoughts? ~ james

The chelate you have probably is mostly chelate and not much mag. For example 1000mg of magnesium malate has about 150mg of magnesium in it. The chelate portion is an organic molecule and weighs quite a bit.

The RDA for magnesium for an adult is 350mg -400mg.
Most people do not consume the RDA...the average is about 200mg if they are lucky.

So I doubt you are getting too much magnesium at this time.
The fact that you have laxative action, means not much is getting absorbed.

I have a magnesium thread here:
http://neurotalk.psychcentral.com/showthread.php?t=1138

Since chelated magnesium is mostly chelate and little magnesium, it appears replacing my daily 750 mg of chelated magnesium with magnesium oxide might be the way to go. Based upon your information, my daily 1550 mg dose might be lowered to something far less of straight magnesium oxide - maybe about 1000 mg. {OH!, I errored in my previous post. I stated my daily regimen was 1050 mg magnesium. I really meant: 1550 mg - 1050 mg before breakfast and 500 mg before supper}. I shall begin experimenting with lesser amounts of {only} magnesium oxide.

I do have one remaining question: From reading the magnesium thread you provided, magnesium citrate is touted a 'a laxative.' Also, magnesium citrate is described as possessing a higher absorption rate than magnesium oxide. I've been led to equate a lower absorption rate with a having a better 'laxative effect.'

Since magnesium oxide appears to have a lower absorption rate, my simple reasoning would conclude that magnesium oxide would function better as a laxative than magnesium citrate?

Thanks ~ james