For the past week or so I have been conducting a very unscientific and subjective experiement on three brands of methyl B12: Jarrow two X 5 mg (for a total of 10 mg per dose), AOR ultra 15 mg, and Solgar two x 5 mg (for a total of 10 mg per dose). I generally take 36 mg of methyl B12 daily and started the Active B12 protocol three months ago. I also take 5.2 mg of folate and 5 mg of ADb12 daily. Before I did the experiment I was taking 15 mg AOR when I got up, 10 mg of Solgar Mb12 and one Enzymatic Therapy Mb12 at midday, and 10 mg Solage Mb12 in the late afternoon.
Since I have a reaction to my first daily dose of MB12 each morning, I started alternating brands in the morning and comparing the results.
During the first round I was deficient in potassium. All three brands caused me to have low potassium symptoms of irregular heartbeats and some degree of jitteriness. I started supplementing potassium again, along with magnesium and repeated the experiment over the next three days. The second time around, the irregular heartbeats diminished considerably allowing me to observe other symptoms that occured within an hour of taking Mb12.
In both rounds, Solgar methyl B12, two 5 mg tablets, caused me to experience tingling and fidgeting, and some degree of a buzzing feeling and brief nerve twinges.
In both rounds Jarrow methyl B12, two 5 mg tablets, caused brief tingling and some fidgeting.
In both rounds, AOR Ultra methyl B12 15 mg produced fewer symptoms. No tingling or fidgeting in the first round, a little in the second.
My conclusion:
Solgar methyl B12 5000 mcg is the strongest of the three.
Jarrow methyl B12 5000 mcg is the second strongest of the three.
AOR Ultra methyl B12 15 mg. is the weakest.
I won't be buying AOR again.
I plan to continue with Jarrow, Solgar and Enzmatic Therapy. I suspect that when I run out of AOR I will be able to replace the 15 mg tab with 10 mg or less of one of the other brands, and actually save money.