For dietary supplement users there is a “rite of passage” that we must all face one day.
Past are the days where you buy whatever brand name has the most marketing. Past are the days where you buy the most expensive supplements. It occurs shortly after you do your wallet a favor and start to look at the value of a supplement.
Then you buy it in bulk.
Like a dragon hoarding it’s gold you amass a large amount of various bottles, from multiple manufacturers, and rest easy knowing that if you did the math right you can just take this supplement everyday for 6 years before it expires—think of the savings!
Yeah, no. Most of us start to minimize our supplement regimens after that point. Rather than just taking 30+ different things we look for compounds that are multifaceted, do multiple things, and hopefully a single product has many of these products in it.
And when it comes to supplements that do multiple things, one of my favorites is alpha-GPC (that article does a good job breaking down exactly what this molecule is.)
This is because it’s both a nootropic—a brain booster, as well as an ergogenic—a performance enhancer.
It encapsulates both brain and body in a single molecule.
Unfortunately, not all is well with this molecule. It has an abusive relationship with scientific publishing.
It was tested for alleviating amnesia and getting multicentre trials back in 1991 and 1994, sorta just fell off the face of the earth research-wise until a study in 2003, then went radio silent until Ziegenfuss over at ISSN made a poster presentation on it in 2008—this is roughly when people in athletic fields started to pay attention to it for the first time.
That was ten years ago and since then we have gotten, like, three more human studies on alpha-GPC. This thing has been getting blue-balled for 27 years …
One of these is a new study from last year and that asked some important questions regarding dosage and added to the somewhat scarce pile of studies on exercise. With more interest in this compound will come more research after all!
Let’s break down this study and see what alpha-GPC is all about.
This particular study is the most recent human study on alpha-GPC and one of the more recent studies overall to make an impact on our understanding of this dietary supplement.
Alpha-GPC, as a small primer, is one of many molecules that’s able to give choline to the body. More basic forms like choline bitartrate are cheaper while the two more expensive forms, CDP-choline and alpha-GPC, help choline get to the brain in higher amounts to help synthesize a neurotransmitter (brain signalling molecule) called acetylcholine.
Acetylcholine, while it has many roles, is primarily known for increasing both learning and muscle contraction; it’s known for being the brain-brawn link.
The scientists, based out of The University of Louisiana at Lafayette, accepted the premise that alpha-GPC was likely to increase strength given how previous research has already demonstrated this but decided to ask a few new questions:
Thus began the study with 4 different groups:
*Active controls are used in a similar theory to placebo controls, existing simply so we can have numbers to compare the tested material against. While placebo controls are inert, however, and answer the question “does this work” active controls tend to be the most common drugs and answer the question “how well does this work compared to other things we know work.”
After initial testing, these supplements were given to participants once in the lab and then they were directed to take the supplements once each morning (with water) for the next six days—the study, overall, lasted a week in time and all supplements were taken fasted.
This means that, for this study, alpha-GPC was not taken as a pre-workout before every exercise protocol. It was taken in the morning on an empty stomach.
This study was testing alpha-GPC in regards to both physical and cognitive benefits. The physical tests were:
Whereas for cognition the subjects were tested for what is known as “psychomotor vigilance” assessed by the Walter Reed palm-held psychomotor vigilance test (PVT henceforth.) PVT is essentially visual reaction time that this video demonstrates; layouts differ but you measure how quickly one can respond to different stimuli.
The researchers assessed physical strength via a lower body and upper body isometric exercise, jumping as a measure of physical power, and also tested reaction time for alpha-GPC compared to both caffeine and placebo.
Finally, there were some stabby stab injections where they took blood after the first dose of alpha-GPC (60 and 120 minutes after, two stabby stabs) where they investigated how much choline, the main compound of alpha-GPC (and what the C stands for) was increased in the blood and whether or not it affected anything else.
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After a week of supplementation the researchers found the following:
The 4 groups were all similar to each other before testing.
After testing, however, it was found that on both isometric exercises (lower body and upper body) both doses of alpha-GPC failed to have an effect. Caffeine, on the other hand, had a minor effect on the lower body test (IMTP) with no effect on the upper body.
For the power test, CMJ, it was found that 250 mg alpha-GPC appeared to increase overall mechanical power output … compared to 500 mg alpha-GPC. Surprisingly there wasn’t a difference between either dose of alpha-GPC to caffeine or placebo or between caffeine and placebo.
Alpha-GPC, taken in the morning for one week, technically had a wee bit of an effect with 250 mg compared to 500 mg but largely failed to improve physical performance.
To put it simply, all groups performed equally on the PVT.
Average reaction time, maximum reaction time, and minor lapses did not significantly differ between caffeine, placebo, and the two differing doses of alpha-GPC.
This study failed to demonstrate an influence of alpha-GPC supplementation on psychomotor vigilance.
Remember that the blood tests were acute. Two pricks taken the day of the first dose, one an hour later and the other another hour after.
It was found that there wasn’t really a difference between the time the blood was taken—whether it was 1 hour or 2 hours later serum choline was increased in both alpha-GPC groups while not changing with caffeine or placebo.
However, the lower dose of alpha-GPC increased serum choline by 132% while the higher dose increased it by 59%. Furthermore, thyroid stimulating hormone appeared to be suppressed with the elevated dose of 500 mg alpha-GPC compared to all other treatments.
However, the researchers said that the decrease in thyroid stimulating hormone was “the most promising result form* this study” (*that’s the problem with quotes, ya gotta keep typos intact) since reduced TSH can be an indicator of increased dopamine levels in the brain.
So it’s reasonable to assume there’s a change in how alpha-GPC acts depending on dose; a lower dose increases serum choline more while a higher dose seems to have more hormonal and perhaps cognitive effects.
For the purpose of this article I’ll just break down other research into the previous three categories as well; physical, cognitive, and serum.
The physical performance results in this study are perhaps the main concern since previous research doing similar tests has found that 600 mg alpha-GPC was ineffective acutely but, after six days, resulted in a significant improvement of IMTP compared to placebo.
The same study showed a trend to improve upper body strength (failed to reach significance) while the poster presentation that started the discussion on alpha-GPC tested upper body power, assessed by bench throws, and found significant improvements with 600 mg acutely.
It should be noted that previous studies used these high doses, perhaps by chance, but if the authors are correct in that 500 mg alpha-GPC or more influences dopamine (which is known to have ergogenic effects) then perhaps acetylcholine is not the only target of this supplement.
Studies assessing physical performance are either null (showing no effect) or show positive effects. Unfortunately, and weirdly, where they show positive effects are all over the map.
This is one of the first studies to assess cognitive performance from alpha-GPC acutely in otherwise cognitively intact adults.
Alpha-GPC and it’s nootropic potential still remains largely theoretical.
Alpha-GPC has been noted to increase blood levels of choline before at a dose of 1,000 mg after 1 to 2 hours but this is the first study to do a comparative analysis.
This also appears to be the first assessing TSH so, ultimately, reflecting on previous research for this section doesn’t seem to really do much. All we have right now are the author’s, and our own, guesses.
Just know that, right now, it seems that alpha-GPC is going the way of Avena sativa where initial studies were actually overdosed and comparative studies are finding that lower doses are winning out in terms of potency.
However, alpha-GPC may be coming towards a bridge where low dose and high dose do different things. Not the first time a choline-providing compound did this as research on CDP-choline has shown 250 mg, but not 500 mg, improved attention.
Based on the serum results and the seemingly contradictory results in some areas, it’s possible that the dose of alpha-GPC determines efficacy more than we would expect normally from a supplement; with different effects from low and high dose alpha-GPC.
When looking at this study and comparing it to previous research what we can, tentatively, conclude would be along the lines of:
But now we return to our state of twiddling our thumbs and waiting for more research.
Future research testing out significantly higher doses (900 mg or more), extending cognitive testing to much more than just reaction time, and trying to dig up whether isometric and power exercises are treated differently by alpha-GPC would shine a lot of light here.
And if you want to hedge your bets, I did include alpha-GPC in Ascend (for other reasons), so I recommend you give it a whirl.