What's actually interesting about this thread is that you can see from peoples' bad experiences whether they are over or under-methylators and whether they have specific allergies/issues.
A negative response to a fairly common supplement can give an insight into general health aspects.
I'm going to throw a few ideas around for consideration:
B vitamin, SAM-e issues - you're probably an over-methylator.
Calcium - you need vitamin D, K & magnesium. Further evidenced by the oxiractem. The anxiety and palpitations suggest overactivity or issues in the dopamine pathway, leading to noepinephrine spikes.
PC heart attack - you have some dangerous rogue gut flora and fauna that may benefit from eviction and replacement. History of antibiotics, medication or hospital stays?
Vitamin C & pericarditis - I'd be looking at a pathogen / infection, including but not limited to lyme disease. Increasing the acidity of your blood may tip you over the edge.
Lion's mane anxiety - you're likely an over-methylator.
DMAE, L-tyrosine, DMAA - 5HT receptor imbalance issues. You're likely an over-methylator.
Choline and yohimbe causing anxiety - you're likely an over-methylator.
Fish oil - rancid product, poor liver function or gut flora issue.
Further reading: http://www.enzymestu...methylation.htm
Yohimbe effects so many serotonin receptors that I don't know if it could simply be chalked up to that simple of an explanation. I don't fit the definition of an "Over-methylator" according to that website and I did not enjoy taking the supplement at all.
As for DMAA, I believe it to be a very ugly stimulant and have had terrible comedowns from it, while the other two you list in the same category I experience little to no effects from.