Alpha-GPC can cause side effects in some people including heartburn, headache, insomnia, dizziness skin rash, and confusion. It may also cause some gastrointestinal irritation, headache or insomnia in a small percentage of people. Not enough is known about the use of alpha-GPC during pregnancy and breast-feeding. Stay on the safe side and avoid use.
Alpha-GPC is known to have very low side effects and interactions. If there are interactions with the substance it is likely to be due to an impure compound or other possible factors (other substances). The unlikelihood for Alpha GPC to cause side effects, make them attractive nootropic compounds.
There are several things to keep in mind with Alpha GPC and choline supplements. Too much of a good thing is possible. One issue that is common in “mega-dosing” of Alpha GPC is a slight fishy odor. This smell is a cause of choline metabolism in the body and can be easily corrected by lowering the dose. Other common side effects in high dosages of Alpha GPC are: increased sweating and salivation, upset stomach and a decreased appetite. These side effects normally occur in much higher than normal doses and are not life threatening.
The LD50 of orally ingested Alpha-GPC appears to be greater than 10,000mg/kg in rats and mice, and subchronic toxicity studies with 1,000mg/kg in rats leads to slight weight loss and reductions in food consumption. It was said that the No Observed Adverse Effect Level (NOAEL) was 150mg/kg over 26 weeks in rats, which is approximately 24mg/kg in humans (for a 150lb person, 1,636mg).
Alpha-GPC does not appear to possess mutagenic activity.
A study over the effect of acute and short-term administration of cholinomimetic drugs on corticosterone secretion in the rat. Centrally acting cholinomimetic drugs have been proposed for the therapy of cognitive disorders in aged subjects. Among the possible adverse side effects of this class of compounds, of great relevance is the stimulatory action on the adrenocortical axis, in view of the toxicity of glucocorticoids for hippocampal neurons and the immune system. The aim of the present study was to evaluate in conscious male rats the effect of acute and short-term administration of three novel cholinomimetic drugs on the release of corticosterone.
The potent agonist of muscarinic receptors RU 35963 strikingly increased corticosterone levels after acute but not after short-term (6 days) administration. Similar results were obtained after administration of the reversible inhibitor of cholinesterase, eptastigmine. In contrast to RU 35963 and eptastigmine, acute administration of a choline precursor, alpha-GPC, only slightly affected plasma corticosterone concentrations after both acute and short-term administration. It is concluded that activation of adrenocortical function by cholinomimetic drugs is a short-lasting event which does not represent an important side effect of these compounds when given on a long-term basis.