Alpha-GPC

Study: This 2003 multicenter, double-blind, randomized, placebo-controlled trial assessed the efficacy and tolerability of Alpha-GPC in patients with mild to moderate Alzheimer’s disease. Patients received 400 mg Alpha-GPC capsules or placebo three times daily (1200 mg total) for 180 days. Cognitive function was evaluated using the Alzheimer’s Disease Assessment Scale (ADAS) for cognition and behavior, Mini-Mental State Examination (MMSE), and other parameters at baseline, 90 days, and 180 days.

Findings: The Alpha-GPC group showed consistent improvement in all assessed parameters (ADAS-Cog, ADAS-Behav, MMSE, etc.) after 90 and 180 days, while the placebo group remained unchanged or worsened. The treatment was well-tolerated with a low incidence of adverse events (up to 8%), including agitation, heartburn, and nausea, with no serious side effects reported.

Study: Conducted in 2021, this single-blind, placebo-controlled trial involved 39 healthy volunteers who self-administered 400 mg/day of Alpha-GPC (200 mg capsules twice daily) or placebo for 2 weeks. Subjective feelings, particularly motivation, were measured using the KOKORO scale three times daily. The study was registered with the University Hospital Medical Information Network (UMIN000044563).

Findings: Alpha-GPC showed a tendency to increase motivation, particularly in the evening, compared to placebo, with no significant effect on anxiety. No serious side effects or toxicities were observed during the 2-week intervention or 12 months post-treatment, confirming the safety of 400 mg/day.

Study: This 2015 randomized, double-blind, placebo-controlled, crossover trial involved 20 healthy participants (10 males, 10 females, aged 22.0 ± 3.4 years) who consumed 200 mg or 400 mg Alpha-GPC, 200 mg caffeine, or placebo. The study measured acute effects on mood, cognitive function, and physical performance (e.g., vertical jump power).

Findings: No statistically significant improvements were observed in mood, cognitive function, or physiological performance due to large individual variability. However, Alpha-GPC showed trends toward improved vertical jump power (+8.5% for 200 mg, +7.5% for 400 mg) compared to placebo, suggesting potential benefits that require further research with optimized dosing and timing.

Study: This 2017 randomized, double-blind, placebo-controlled trial involved 48 healthy, college-aged males who received 250 mg or 500 mg Alpha-GPC, 200 mg caffeine, or placebo daily for 7 days. Assessments included countermovement jump (CMJ), isometric mid-thigh pull, upper body isometric strength, and psychomotor vigilance. Blood samples measured serum free choline and thyroid-stimulating hormone.

Findings: The 250 mg and 500 mg Alpha-GPC doses increased serum free choline and improved countermovement jump performance, suggesting an ergogenic effect. No significant improvements were noted in isometric strength or psychomotor vigilance, and results varied due to individual differences. The study supports Alpha-GPC’s role in enhancing power output.

Study: This randomized, double-blind, placebo-controlled, crossover trial (retrospectively registered as NCT06690619) involved 20 resistance-trained males (aged 31.3 ± 11.0 years) who consumed 315 mg (low dose, LD) or 630 mg (high dose, HD) Alpha-GPC or placebo. Cognitive performance was assessed 60 minutes post-ingestion using Stroop, N-Back, and Flanker tests, alongside visual analog scales and hemodynamics.

Findings: Both LD and HD Alpha-GPC significantly improved Stroop test performance (total score and completion time) compared to placebo, with HD showing a trend for faster Flanker test reaction times. No significant effects were observed on N-Back, physical performance, or growth hormone levels. Heart rate and blood pressure changes remained within normal ranges.

Study: This 1991 trial investigated Alpha-GPC’s effects on scopolamine-induced amnesia in healthy subjects. Participants received 400 mg Alpha-GPC or placebo for 10 days before scopolamine administration, with memory and attention tasks assessed.

Findings: Alpha-GPC reduced scopolamine-induced memory impairments, improving performance on memory and attention tasks, likely due to increased acetylcholine availability. The study supports Alpha-GPC’s role as a cognition enhancer.

Study: This 1991 multicenter trial compared Alpha-GPC (1200 mg/day) with cytosine diphosphocholine in patients with vascular dementia. Outcomes included cognitive, behavioral, and verbal symptoms over 90 days.

Findings: Alpha-GPC (1200 mg/day) improved behavioral, memory, and verbal symptoms in vascular dementia patients, with effects comparable or superior to cytosine diphosphocholine. The treatment was well-tolerated with minimal side effects.

Study: This 1994 multicenter trial involved patients recovering from acute stroke or transient ischemic attack (TIA). Patients received 1000 mg Alpha-GPC injections for 28 days, followed by 400 mg oral Alpha-GPC three times daily for 5 months. Cognitive recovery was assessed using the Mini-Mental State Test and other measures.

Findings: At the trial’s end, 71% of patients showed no cognitive decline or forgetfulness, with significant improvements in Mini-Mental State Test scores. Alpha-GPC was well-tolerated with a low rate of adverse events.

Study: This nationwide longitudinal cohort study in South Korea used time-dependent Cox regression analysis to assess Alpha-GPC’s impact on dementia progression. Patients were classified as Alpha-GPC users or non-users based on prescription records, with primary outcomes being progression to Alzheimer’s disease dementia or vascular dementia, and stroke risk as a secondary outcome.

Findings: Alpha-GPC users had a lower risk of progressing to Alzheimer’s disease dementia (hazard ratio = 0.899, 95% CI: 0.882–0.918) and vascular dementia (hazard ratio = 0.832, 95% CI: 0.801–0.865). Stroke risk was reduced in patients who did not progress to dementia, but not in those who did. The effect was significant in patients under 65.