Choline Bitartrate, Choline Chloride and Choline Citrate are relatively cheap and found in many low-cost natural nootropic together with a choline supplement. However, they have low oral bioavailability and do not cross the blood-brain barrier in large amounts. Alpha Glycerylphosphorylcholine is a phospholipid form of choline that demonstrates a number of nootropic effects on its own. As a supplement, it is made from soy lecithin and it also occurs naturally in the human brain and body. As a phospholipid, it is fat soluble and has a similar structural makeup to the cell membranes of our neurons. It can be incorporated into these membranes and is purported to promote brain cell health. Alpha GPC also boosts circulation to the brain and has been shown to increase oxygen and glucose uptake. It has also been demonstrated to increase human growth hormone levels following a workout. It requires the smallest effective dosage to increase acetylcholine levels and contains more choline by weight than the related compound Cytidine 5′-phosphocholine. This means that you need a 46% lower dosage of Alpha GPC compared to CDP Choline.
CDP Choline is a phospholipid that gets broken down into choline and cytidine in the human body. The cytidine is further converted into uridine, which is a nucleotide base involved in the synthesis of cell membranes. CDP Choline is used to make phosphatidylcholine (PC) in the brain. It has been shown to increase acetylcholine levels and demonstrates neuroprotective effects. Citicoline has been used to treat memory disorders and to increase attention and learning. Stacking Aniracetam together with a choline supplement, Centrophenoxine (Lucidril, Meclofenoxate) is another popular option due to the neuroprotectant and antioxidant effects of this choline source.
The different forms of supplement stack.
Centrophenoxine is an enhanced form of DMAE (Dimethylaminoethanol) that demonstrates greater oral bioavailability and better penetrates the blood-brain barrier. DMAE is a modified choline molecule that has one less methyl group in its chemical structure. In addition to increasing acetylcholine levels in the brain, it has also been shown to reduce the accumulation of beta-amyloid plaque which is implicated in cognitive decline as well as Alzheimer’s disease. While the use of this supplement can serve as a precursor to acetylcholine and increase levels of this neurotransmitter in synaptic vesicles, it requires a significantly larger dosage to achieve desired nootropic effects.
Choline bitartrate is poorly absorbed from the gastrointestinal tract. In some individuals, it has been reported to cause diarrhoea, stomach upset and indigestion due to how it is processed by bacteria in the gut. Another nootropic supplement used to promote acetylcholine synthesis is Acetyl L-Carnitine (ALCAR). This natural dietary supplement contains the amino acid L-Carnitine bound to an acetyl group. When it is metabolized in the body, the acetyl molecule separates from the Carnitine. The acetyl group then binds to Coenzyme A to produce Acetyl-COA. Acetyl-COA is involved in a number of important biochemical reactions related to energy metabolism and the Krebs cycle. This molecule is also used to synthesize acetylcholine. Acetyl combines together with choline in a reaction catalyzed by choline acetyltransferase (ChAT).