Benefits
Cholinergic support for cognition
In a crossover trial in 20 young resistance-trained men, a single 315 or 630 mg dose improved Stroop test scores versus placebo, while two other attention and memory tests did not change; the study was industry sponsored. Another small crossover trial at 200 or 400 mg found no clear effect on cognition or mood.
Power output and athletic performance
In college-age men, 600 mg a day for six days increased lower-body isometric force versus placebo in a 13-person crossover trial, and 250 mg a day for a week improved jump power in a 48-person trial without changing isometric strength or reaction tests. Single doses in two other trials did not significantly change jump or other performance tests.
Growth hormone response
In eight young men, a single 1,000 mg dose raised blood growth hormone 60 minutes later, while placebo did not. In a later trial, 315 or 630 mg taken before resistance exercise did not change growth hormone, and a performance benefit from short growth hormone rises has not been shown.
Motivation and mood
In a single-blind trial of 39 healthy volunteers, 400 mg a day for two weeks raised self-rated nighttime motivation compared with placebo, with a trend toward higher daytime motivation and no change in anxiety.
Mechanism of action
Increases Acetylcholine Synthesis
Alpha-GPC supplies choline, which neurons combine with acetyl-CoA through the enzyme choline acetyltransferase to make acetylcholine, a signaling chemical involved in memory, attention and muscle contraction. Oral doses of 250 to 500 mg raised blood free choline in a controlled trial.
Supports Cell Membrane Integrity
Its choline can be used to build phosphatidylcholine, a main phospholipid in nerve cell membranes.
Growth Hormone Signaling
Cholinergic signaling may influence growth hormone release from the pituitary gland. In people, one small trial found a rise after 1,000 mg and another found no change at 315 to 630 mg.
Counteracts Anticholinergic Effects
In healthy volunteers, oral pretreatment with alpha-GPC reduced the attention and memory impairment caused by scopolamine, a drug that blocks acetylcholine receptors.
Modulates Dopaminergic and Serotonergic Systems
Alpha-GPC may indirectly influence dopamine and serotonin pathways through cholinergic signaling. Human data on mood are limited to a single-blind study that found increased nighttime motivation but no change in anxiety.
Fat Oxidation Markers
In one small trial, a single 1,000 mg dose raised blood free fatty acids and ketones two hours later, which the authors read as increased fat burning in the liver.
Clinical trials
Multicenter, double-blind, randomized, placebo-controlled trial of choline alfoscerate 400 mg three times daily (1,200 mg/day) for 180 days. (De Jesus Moreno Moreno 2003, Clin Ther)
261 adults aged 60 to 80 with mild to moderate Alzheimer's disease.
ADAS-Cog scores improved by 3.20 points at day 180 with choline alfoscerate and worsened by 2.90 points with placebo, with significant differences on the MMSE and global scales. This is drug evidence in a disease population, not evidence for supplement use in healthy adults.
Randomized, double-blind, placebo-controlled crossover trial of a single 315 mg or 630 mg dose (GeniusPure) given 60 minutes before cognitive testing and resistance exercise; sponsored by NNB Nutrition. (Kerksick 2024, Nutrients)
20 resistance-trained men, average age 31.
Both doses improved Stroop test total score versus placebo, and 630 mg shortened Stroop completion time. There were no significant differences on the Flanker and N-Back tests, and no changes in mood scales, physical performance or growth hormone. The author is a paid scientific advisor to the sponsor.
Randomized, double-blind, placebo-controlled crossover study of 200 mg or 400 mg alpha-GPC, 200 mg caffeine or placebo, tested 30 minutes after intake; supported by Chemi Nutra. (Parker et al. 2015, J Int Soc Sports Nutr)
20 healthy young adults (10 men, 10 women), average age 22.
Serial subtraction times and vertical jump peak power were numerically better with alpha-GPC, but apart from caffeine causing more jitteriness than 400 mg alpha-GPC, there were no statistically significant differences between groups in mood, cognition or physical performance.
Randomized study of 10 days of oral alpha-GPC or placebo pretreatment, followed by an injection of scopolamine or placebo on day 11. (Canal et al. 1991, Int J Clin Pharmacol Ther Toxicol)
32 healthy young volunteers.
Alpha-GPC pretreatment counteracted the attention and memory impairment caused by scopolamine, a drug that blocks acetylcholine receptors.
Single-blind, placebo-controlled trial of 400 mg/day alpha-GPC (200 mg twice daily) or placebo for 2 weeks, with emotional state rated three times daily on the KOKORO scale. (Tamura et al. 2021, Nutrients)
39 healthy volunteers.
Alpha-GPC showed a trend toward higher daytime motivation and significantly higher nighttime motivation than placebo. There was no effect on anxiety.
Double-blind, placebo-controlled crossover trial of 600 mg/day alpha-GPC for 6 days with a one-week washout. (Bellar et al. 2015, J Int Soc Sports Nutr)
13 college-aged men.
Lower-body isometric mid-thigh pull peak force rose more with alpha-GPC than placebo (98.8 N vs -39.0 N change). Upper-body force trended higher but the difference was not significant.
Randomized trial of 250 mg or 500 mg alpha-GPC, 200 mg caffeine or placebo daily for 7 days. (Marcus et al. 2017, J Int Soc Sports Nutr)
48 healthy college-aged men.
Countermovement jump maximum velocity and power differed between groups, with the 250 mg group improving most. There were no differences in isometric strength or psychomotor vigilance. Serum free choline rose 132 percent with 500 mg and 59 percent with 250 mg versus placebo, and 500 mg lowered TSH.
Double-blind, randomized crossover study of a single 1,000 mg dose or placebo, with blood taken at baseline, 60 and 120 minutes. (Kawamura et al. 2012, Nutrition)
8 healthy young men, average age 25.
Plasma free choline rose at 60 and 120 minutes, and growth hormone rose significantly at 60 minutes after alpha-GPC but not after placebo. Free fatty acids and ketone bodies rose at 120 minutes.