Really? Pretty much everything I've seen written by a reputable source (ie, not some junk science website) indicates all this stuff is a scam like just about all the supplements out there.
Alpha-GPC has been shown to be effective in treating alzheimers that's marked by acetylcholine dysfunction. It's actually prescribed for that purpose. I find that fairly compelling that it's actually stimulating acetylcholine release in the brain, which is the same reason nicotine is also considered to be a cognitive enhancer. Acetylcholine mediates attention, focus, and mental energy.
However, I have not found a study that specifically shows alpha-gpc is a cognitive enhancer in normal individuals. But at least its shown to be active in the brain and it's not one of those all-natural bullshit things that you can down the whole bottle and be fine.
Here are a few studies
Amenta F, Del Valle M, Vega JA, Zaccheo D. Age-related structural changes in the rat cerebellar cortex: effect of choline alfoscerate treatment.
Mech Ageing Dev. 1991; 61: 173-186.
Amenta F, Ferrante F, Vega JA, Zaccheo D. Long term choline alfoscerate treatment counters age-dependent microanatomical changes in rat brain.
Neuropsychopharmacol Biol Psychiatry. 1994; 18:915-924.Ceda GP.
Ceresini G. Denti L, et al. Alpha-glycerylphosphorylcholine administration increases the GH responses to GHRH of young and elderly subjects.
Horm Metab Res. 1992; 24:119-121.
Ricci A, Bronzetti E, Vega JA, Amenta F. Oral choline alfoscerate counteracts age-dependent loss of mossy fibres in the rat hippocampus.
Mech Ageing Dev. 1992; 66: 81-91.