Choline-containing compound alpha GPC is believed to support strength training via acetylcholine activity.
Alpha GPC is a naturally-occuring compound that contains choline, an essential nutrient with a wide range of roles in human health. Alpha GPC may have potential as a pre-workout supplement through:
- Enhancing acetylcholine levels. Acetylcholine is a neurotransmitter involved in muscle contraction and growth hormone release.
Alpha GPC, also known as choline alfoscerate and alpha-glycerophosphocholine, is a natural compound derived from soy lecithin, a fatty substance commonly used as a food additive. Alpha GPC contains the active ingredient choline – an essential nutrient involved in multiple bodily processes, including the production of the neurotransmitter acetylcholine, cell membrane function, and transport of fats.
Choline is naturally produced in the human body, but dietary intake is required; high-choline foods include both animal and plant products such as chicken, salmon, soy, wheat, quinoa, and almonds. In addition, egg yolk provide the highest concentration of dietary choline at 125 mg of per egg.
Alpha GPC is considered one of the best ways to supplement choline because of its rapid absorption and ability to easily cross the blood-brain barrier. Furthermore, recent research suggests that alpha GPC may be able to enhance muscle performance. But despite promising findings, more research is needed to say anything conclusive.
How Alpha GPC Might Help With PWO Formulas
Enhanced acetylcholine levels
Alpha GPC has been shown to be one of the most effective ways to increase the body’s choline levels. Researchers believe that enhanced choline availability allows neurons to increase their production and release of acetylcholine, a neurotransmitter involved in memory function, neuro-muscular interaction, and other processes. In turn, acetylcholine appears to have two biological activities relevant to exercise:
- Motor neurons use acetylcholine to activate muscle, causing it to contract; increased contraction may improve muscle performance
- Acetylcholine supports the hormones adrenaline and noradrenaline, which enhance growth hormone (GH) release; GH is linked to muscle growth, fat loss and other beneficial outcomes of working out4
Alpha GPC’s Proposed Benefits
The main proposed benefit of alpha GPC is improved power output during resistance training. Moreover, alpha GPC may further boost the exercise-induced release of growth hormone, which promotes muscle growth, strength, and fat loss.
Although some supplements also advertise that alpha GPC can improve mental focus in healthy individuals, this claim is not based on any research evidence. Studies on age-associated cognitive impairment and related disorders suggest that alpha GPC may also provide a mild cognitive boost for older individuals, which could be indirectly beneficial for exercise.5
Alpha GPC has not been studied as a pre-workout supplement in animals. However, studies in rats confirm that alpha GPC can:
- Effectively raise brain acetylcholine levels in a dose-dependant manner6
Although human trials of alpha GPC are promising, there is simply too little research to date. Moreover, the results of some studies may biased due to receiving support from supplement companies and having a small sample size.
This double-blind, randomized, crossover study examined whether alpha GPC has any impact on growth hormone (GH). Eight young men were assigned to receive placebo or alpha GPC (1000 mg) and had their blood tested before supplementation, and 60 and 120 min after. The groups were later switched so all participants tried both treatments. Alpha GPC was found to boost choline levels, GH secretion for up to 2 hours, and the usage of fats for energy.
- The researchers concluded that “a single dose of GPC increases growth hormone secretion and hepatic fat oxidation, with concomitant increases in choline levels, in young adults“7
In this randomized, placebo-controlled, crossover trial, researchers examined whether alpha GPC could increase growth hormone levels and simultaneously result in improved resistance training performance. Seven men with two years of training experience took alpha GPC (600 mg) or placebo 90 minutes before completing 6 sets of 10 reps of Smith Machine squats set at 70% of 1-rep maximum, and 3 sets of bench press throws set at 50% of 1-rep max.
- The researchers concluded that “a single 600 mg dose of A-GPC (as AlphaSize™), when administered 90 minutes prior to resistance exercise, increases post-exercise serum GH and peak bench press force“8
In this double-blind, placebo-controlled crossover trial, 13 male college students took placebo or A-GPC (600 mg) daily for 6 days. They performed lower and upper body strength tests before and after being supplemented, and the groups were switched a week later so that all participants tried both treatments. A-GPC resulted in a substantial peak force improvement in the lower body test (A-GPC: 98.8 Newtons vs Placebo: −39.0 Newtons), and a small, but not statistically-significant improvement of 3% on the upper body test (A-GPC: 50.9 N vs Placebo: −14.9 N).
- The researchers concluded that “The results of the study suggest that A-GPC is effective at increasing lower body force production after 6 days of supplementation. A similar trend was noted in upper body isometric strength, however; this failed to attain statistical significance”9
Dosage for Pre-Workout
- Successful human trials have used doses of 600-1000 mg
- Standalone alpha GPC supplements come in 300 mg capsules
- Pre-workout formulas that include alpha GPC typically provide 150-300 mg per scoop
- Alpha GPC is about 40% choline by weight (e.g. 100 mg contains 40 mg choline)
Supplements in Review Recommendation
- Alpha-GPC, 600 mg.
It’s too early to recommend alpha GPC, so you will have to test for yourself to see if it works. What little research has been done had small sample sizes and possible funding bias. However, the potential strength training benefits are substantial enough to consider giving alpha GPC a try. In general, when it comes to choline supplements for PWO, nootropic, or other supplements, we recommend Citicoline as superior to Alpha-GPC; with both phosphatidylcholine and uridine in its profile, it supplies 2-in-1 nootropic activity.
Regardless, Alpha GPC is safe and potentially effective option and 600 mg appears to be a good starting point. 600 mg is the most common dose used by successful clinical trials, and translates well to the doses taken for brain health.
- Warber JP et al. The effects of choline supplementation on physical performance. Int J Sport Nutr Exerc Metab. 2000 Jun;10(2):170-81. ↩
- Penry JT, Manore MM. Spector SA et al. Effect of choline supplementation on fatigue in trained cyclists. Med Sci Sports Exerc. 1995 May;27(5):668-73. ↩
- Choline: an important micronutrient for maximal endurance-exercise performance? Int J Sport Nutr Exerc Metab. 2008 Apr;18(2):191-203. ↩
- Ceda GP et al. alpha-Glycerylphosphorylcholine administration increases the GH responses to GHRH of young and elderly subjects. Horm Metab Res. 1992 Mar;24(3):119-21. ↩
- De Jesus Moreno Moreno M. Cognitive improvement in mild to moderate Alzheimer’s dementia after treatment with the acetylcholine precursor choline alfoscerate: a multicenter, double-blind, randomized, placebo-controlled trial. Clin Ther. 2003 Jan;25(1):178-93. ↩
- Sigala S et al. L-alpha-glycerylphosphorylcholine antagonizes scopolamine-induced amnesia and enhances hippocampal cholinergic transmission in the rat. Eur J Pharmacol. 1992 Feb 18;211(3):351-8. ↩
- Kawamura T et al. Glycerophosphocholine enhances growth hormone secretion and fat oxidation in young adults. Nutrition. 2012 Nov-Dec;28(11-12):1122-6. ↩
- Ziegenfuss T et al. Acute supplementation with alpha-glycerylphosphorylcholine augments growth hormone response to, and peak force production during, resistance exercise. J Int Soc Sports Nutr. 2008; 5(Suppl 1): P15. ↩
- Bellar D et al. The effect of 6 days of alpha glycerylphosphorylcholine on isometric strength. J Int Soc Sports Nutr. 2015 Nov 17;12:42. ↩