Home Ingredients AlphaSize® (Alpha-GPC — Chemi Nutra)
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AlphaSize® (Alpha-GPC — Chemi Nutra)

Evidence Level
Limited
1 Clinical Trial
3 Documented Benefits
2/5 Evidence Score

AlphaSize® is a branded, high-purity alpha-GPC (alpha-glycerylphosphorylcholine), a choline compound that readily crosses into the brain and serves as a building block for the neurotransmitter acetylcholine. Made by Chemi Nutra, it is used both as a nootropic for memory and focus and as a sports ingredient studied for power output. Alpha-GPC is one of the better-studied cholinergic compounds.

Studied Dose 300 to 600 mg per day for cognition; 600 mg per day in one sports trial (Bellar) and 250 to 500 mg in another (Marcus).
Active Compound Alpha-glycerylphosphorylcholine (alpha-GPC), a highly bioavailable choline source and precursor to acetylcholine and membrane phospholipids.

Benefits

Memory and cognition

By supplying choline for acetylcholine synthesis, alpha-GPC is used to support focus and memory in healthy adults. Most controlled cognitive data come from generic choline alphoscerate in older adults with dementia, not from the AlphaSize brand or from healthy users, so its everyday cognitive effect is not established.

Supported by Trial 1

Power and exercise output

Taken over several days of training, alpha-GPC has been studied in two small trials for lower-body power and force. Results are mixed: one crossover trial (13 men) found greater peak isometric force, while a larger trial (48 men) found no change in most strength measures and only a signal on jump power. It remains a popular pre-workout ingredient.

Supported by Trial 1

Acetylcholine support

As a direct precursor, it helps maintain the acetylcholine signaling involved in learning, muscle activation, and focus.

Mechanism of action

1

Acetylcholine precursor

Alpha-GPC is cleaved to choline, which feeds acetylcholine production in the brain and at the neuromuscular junction, supporting cognition and muscle contraction.

2

Membrane phospholipid donor

Its glycerophosphate backbone contributes to phospholipid synthesis, supporting neuronal membrane integrity.

Clinical trials

1
Generic choline alphoscerate vs citicoline in dementia patients (systematic review, not an AlphaSize trial)
PubMed

Systematic review and meta-analysis of three randomized trials (358 participants) comparing generic choline alphoscerate with citicoline in patients with dementia disorders. (Sagaro and Amenta 2025, Frontiers in Neurology). This is a review of the generic compound, not a trial of AlphaSize.

Adults with dementia disorders (a disease population, not healthy adults).

Pooled across three trials, generic choline alphoscerate improved overall geriatric clinical scores versus citicoline, but there was no significant difference on memory or word-fluency tests. The trials used generic choline alphoscerate in dementia patients, not the AlphaSize brand in healthy adults.

Side effects and drug interactions

Common Potential side effects

Generally well-tolerated — side effects are uncommon at normal doses.
Mild headache, heartburn, or dizziness is occasionally reported.
High doses may cause nervousness in sensitive people.

Important Drug interactions

Anticholinergic drugs — alpha-GPC opposes their action.
Scopolamine and similar agents — cholinergic ingredients may interact.
Tell your doctor if you take medication for memory or Alzheimer's disease.

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Frequently asked questions about AlphaSize® (Alpha-GPC — Chemi Nutra)

What is AlphaSize?

AlphaSize® is a branded, high-purity alpha-GPC (alpha-glycerylphosphorylcholine), a choline compound that readily crosses into the brain and serves as a building block for the neurotransmitter acetylcholine.

What is AlphaSize used for?

AlphaSize is researched primarily for Cognitive and Athletic Performance. By supplying choline for acetylcholine synthesis, alpha-GPC is used to support focus and memory in healthy adults. Most controlled cognitive data come from generic choline alphoscerate in older adults with dementia, not from the AlphaSize b…

What is the recommended dosage of AlphaSize?

The clinically studied dose is 300 to 600 mg per day for cognition; 600 mg per day in one sports trial (Bellar) and 250 to 500 mg in another (Marcus). Always follow the product label and check with a healthcare provider for personal advice.

Is AlphaSize safe, and does it have side effects?

For most healthy adults, AlphaSize is well tolerated at studied doses. Reported effects can include: Generally well-tolerated — side effects are uncommon at normal doses. Mild headache, heartburn, or dizziness is occasionally reported. It may also interact with some medications. AlphaSize is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does AlphaSize interact with any medications?

Possible interactions include: Anticholinergic drugs — alpha-GPC opposes their action. Scopolamine and similar agents — cholinergic ingredients may interact. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for AlphaSize?

NutraSmarts rates the evidence for AlphaSize as Limited (2 out of 5). It is backed by 1 clinical trial and 3 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(3 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Sagaro GG, Amenta F. Comparison of the effects of choline alphoscerate and citicoline in patients with dementia disorders: a systematic review and meta-analysis. Front Neurol. 2025;16:1649661..PubMedUsed to support: A systematic review and meta-analysis of three randomized trials (358 participants) in patients with dementia disorders, comparing generic choline alphoscerate with citicoline. Choline alphoscerate improved overall geriatric clinical scores, but there was no significant difference on memory or word-fluency tests. This is generic choline alphoscerate in a disease population, not the AlphaSize brand and not healthy adults.
  2. Bellar D, LeBlanc NR, Campbell B. The effect of 6 days of alpha glycerylphosphorylcholine on isometric strength. J Int Soc Sports Nutr. 2015;12:42..PubMedUsed to support: A double-blind, placebo-controlled crossover trial in 13 college-aged men. After 6 days of alpha-GPC at 600 mg/day, lower-body peak isometric force increased more than with placebo (p = 0.044); an upper-body force measure trended higher but was not significant. The material was Chemi Nutra's AlphaSize. A small single-site trial.
  3. Marcus L, Soileau J, Judge LW, Bellar D. Evaluation of the effects of two doses of alpha glycerylphosphorylcholine on physical and psychomotor performance. J Int Soc Sports Nutr. 2017;14:39..PubMedUsed to support: A randomized trial in 48 college-aged men comparing 250 mg and 500 mg alpha-GPC (AlphaSize) with caffeine and placebo over 7 days. There was no difference between groups on mid-thigh pull, upper-body strength, or psychomotor vigilance; the 250 mg group showed higher countermovement-jump velocity and power, and serum free choline rose with alpha-GPC. A small trial that was null on most strength outcomes.