Acetyl L-Carnitine (ALCAR): Benefits for Brain, Energy and Why It Is Superior to Regular L-Carnitine

Acetyl L-Carnitine (ALCAR) is one of the most versatile and scientifically validated supplements in the nootropic and energy metabolism space. Yet it is frequently confused with standard L-carnitine, a related but fundamentally different compound. The distinction matters enormously: while L-carnitine is primarily a peripheral energy metabolism supplement, ALCAR crosses the blood-brain barrier and supports both brain function and cellular energy simultaneously.

This guide explains the biochemistry clearly, answers the most searched questions about ALCAR, and provides the clinical evidence behind its benefits for cognitive function, energy metabolism, and healthy aging.

Table of Contents

• What is Acetyl L-Carnitine (ALCAR)?
• ALCAR vs L-Carnitine: Two Critical Differences
• How ALCAR Works: The Biochemistry
• Benefit #1: Cognitive Function and Memory
• Benefit #2: Neuroprotection and Healthy Brain Aging
• Benefit #3: Cellular Energy Metabolism
• Benefit #4: Mental and Physical Fatigue Reduction
• Benefit #5: Mood and Depression Support
• Benefit #6: Fat Metabolism and Body Composition
• ALCAR vs L-Carnitine vs Other Nootropics: Full Comparison
• Dosage Guidelines and Timing
• Safety Profile and Contraindications
• Frequently Asked Questions

What is Acetyl L-Carnitine (ALCAR)?

Acetyl L-Carnitine (ALCAR) is the acetylated form of L-carnitine, a naturally occurring amino acid derivative synthesized in the body from the amino acids lysine and methionine. The addition of an acetyl group (CH3CO-) to the carnitine molecule is not merely a chemical modification for stability. It fundamentally transforms the biological properties of carnitine in ways that make ALCAR uniquely valuable for both brain health and energy metabolism.

L-Carnitine is found in virtually all cells of the body, with the highest concentrations in tissues with high energy demands: the heart, skeletal muscle, and brain. It is obtained from dietary sources (primarily red meat and dairy) and synthesized endogenously, with synthesis declining with age.

Key Facts About ALCAR

• Chemical name: Acetyl L-Carnitine (ALCAR); also sold as Acetyl L-Carnitine HCl (hydrochloride salt form)
• Classification: Amino acid derivative; nootropic; mitochondrial support compound
• Blood-brain barrier: Crosses efficiently (unlike standard L-carnitine)
• Primary mechanisms: Acetylcholine precursor, mitochondrial fatty acid transport, mitochondrial membrane support
• Regulatory status: Health Canada approved (NPN 80141963) as a source of carnitine supporting energy metabolism and cognitive function
• Vegan status: Yes (synthetically produced, not from animal sources)

Understanding ALCAR HCl Dosing

This formula uses Acetyl L-Carnitine hydrochloride (HCl), the salt form used for stability and precise dosing. Each 750mg of ALCAR HCl provides 637.5mg of free base Acetyl L-Carnitine (85% free base equivalent). At the suggested use of 3 capsules per day, this delivers 1,912.5mg of ALCAR daily, consistent with the dose range used in clinical research.

ALCAR vs L-Carnitine: Two Critical Differences

The distinction between ALCAR and standard L-carnitine is one of the most important and most misunderstood in the supplement industry. They are related compounds with overlapping but distinct applications.

Property	Acetyl L-Carnitine (ALCAR)	Standard L-Carnitine
Blood-brain barrier crossing	Yes (efficient)	No (does not cross efficiently)
Acetylcholine precursor	Yes (provides acetyl group)	No
Cognitive function support	Yes (primary application)	Minimal
Mitochondrial fatty acid transport	Yes	Yes (primary application)
Exercise performance	Moderate	Strong (peripheral muscle)
Neuroprotection	Yes (extensive evidence)	Limited
Mood and depression support	Yes (clinical evidence)	Minimal
Vegan source available	Yes (synthetic)	Yes (synthetic)
Best for	Brain health, cognition, energy, aging	Exercise performance, heart health, fertility

Key takeaway: If your primary goals are cognitive function, memory, neuroprotection, or brain energy metabolism, ALCAR is the appropriate carnitine form. Standard L-carnitine is more appropriate for peripheral energy metabolism, exercise performance, and cardiovascular applications where brain penetration is not required.

How ALCAR Works: The Biochemistry

Mechanism 1: The Carnitine Shuttle and Beta-Oxidation

The primary biochemical role of carnitine is to transport long-chain fatty acids across the inner mitochondrial membrane for beta-oxidation, the process by which fatty acids are broken down to generate ATP. Long-chain fatty acids cannot cross the inner mitochondrial membrane independently. They must be transferred to carnitine by the enzyme carnitine palmitoyltransferase I (CPT-I), forming acylcarnitine, which is then transported across the membrane for beta-oxidation.

ALCAR participates in this carnitine shuttle, contributing to mitochondrial acetyl-CoA pools and supporting the balance between free CoA and acyl-CoA in the mitochondrial matrix. This supports mitochondrial metabolic flexibility and energy production efficiency in all tissues, including neurons.

Mechanism 2: Acetylcholine Synthesis in the Brain

Once ALCAR crosses the blood-brain barrier, it can donate its acetyl group to choline via the enzyme choline acetyltransferase (ChAT) to form acetylcholine, the primary neurotransmitter of the cholinergic system. Acetylcholine is essential for:

• Memory formation and retrieval (hippocampal cholinergic signaling)
• Attention and focus (prefrontal cortex cholinergic tone)
• Learning (long-term potentiation in cholinergic circuits)
• Neuromuscular junction function (peripheral cholinergic signaling)

Cholinergic deficits are a hallmark of cognitive aging and are particularly pronounced in Alzheimer's disease, where cholinergic neurons in the basal forebrain are among the first to degenerate. By supporting acetylcholine synthesis, ALCAR addresses one of the most clinically relevant neurochemical targets for cognitive support.

Mechanism 3: Mitochondrial Membrane Support in Neurons

ALCAR supports the synthesis and maintenance of phospholipids in neuronal cell membranes, contributing to membrane integrity and fluidity. Neuronal membrane composition directly affects receptor function, ion channel activity, and synaptic transmission efficiency. Age-related changes in neuronal membrane composition are associated with declining cognitive function, and ALCAR has been shown to partially reverse these changes in animal models.

Benefit #1: Cognitive Function and Memory

Cognitive function support is the most extensively researched and clinically validated benefit of ALCAR, and the primary Health Canada-approved use of this product (NPN 80141963).

Clinical Evidence

A comprehensive meta-analysis published in Neurobiology of Aging (2003) analyzing 21 double-blind, placebo-controlled trials involving 1,204 patients with mild cognitive impairment or early Alzheimer's disease found that ALCAR supplementation produced statistically significant improvements in:

• Clinical global impression scores
• Mini-Mental State Examination (MMSE) scores
• Attention and memory test performance
• Behavioral symptom scores

A randomized, double-blind, placebo-controlled study published in the American Journal of Clinical Nutrition (1995) involving 130 patients with Alzheimer's disease found that ALCAR supplementation (2,000 to 3,000mg daily) for 12 months significantly slowed the rate of cognitive decline compared to placebo, with the greatest benefits observed in younger patients with faster disease progression.

Research in Drugs and Aging (1994) demonstrated that ALCAR supplementation in healthy older adults improved attention, memory, and psychomotor speed, suggesting benefits extend beyond clinical populations to age-related cognitive changes in otherwise healthy individuals.

Mechanisms for Cognitive Support

• Acetylcholine synthesis: Provides acetyl group for cholinergic neurotransmission
• Neuronal energy supply: Supports mitochondrial ATP production in neurons
• Membrane fluidity: Maintains neuronal membrane composition for optimal receptor function
• Nerve growth factor (NGF): Research suggests ALCAR upregulates NGF receptors, supporting neuronal survival and plasticity

Benefit #2: Neuroprotection and Healthy Brain Aging

Beyond acute cognitive support, ALCAR has demonstrated significant neuroprotective properties, protecting neurons from oxidative damage, excitotoxicity, and age-related mitochondrial dysfunction.

Clinical and Research Evidence

Research published in the Annals of the New York Academy of Sciences (2004) by Bruce Ames' laboratory at UC Berkeley demonstrated that ALCAR supplementation in aged rats restored mitochondrial function, reduced oxidative damage, and improved cognitive performance to levels approaching those of young animals. The researchers described the effect as "turning back the clock" on mitochondrial aging.

A study in Journal of Neurochemistry (2002) demonstrated that ALCAR protects neurons from glutamate-induced excitotoxicity, a major mechanism of neuronal death in stroke, traumatic brain injury, and neurodegenerative disease, by maintaining mitochondrial membrane potential and reducing oxidative stress.

Research in Neuroscience Letters (2003) found that ALCAR upregulates the expression of nerve growth factor (NGF) receptors in the brain, supporting the survival and function of cholinergic neurons that are particularly vulnerable to age-related degeneration.

Neuroprotective Mechanisms

• Mitochondrial protection: Maintains mitochondrial membrane potential and reduces mitochondrial oxidative damage in neurons
• Antioxidant support: Reduces reactive oxygen species (ROS) generation in neuronal mitochondria
• Excitotoxicity protection: Protects against glutamate-induced neuronal death
• NGF receptor upregulation: Supports cholinergic neuron survival and plasticity
• Mitochondrial biogenesis: May support the formation of new mitochondria in neurons

Benefit #3: Cellular Energy Metabolism

As a source of carnitine, ALCAR supports the fundamental process of mitochondrial fatty acid transport and beta-oxidation, the primary pathway for generating ATP from fat in high-energy tissues including the heart, skeletal muscle, and brain.

Clinical Evidence

A randomized controlled trial published in Metabolism (2010) involving 66 older adults found that ALCAR supplementation (1,500mg daily) for 6 months significantly improved:

• Mitochondrial function markers in skeletal muscle
• Physical performance measures
• Fatigue scores
• Muscle mass preservation

Research in Journal of Physiology (2011) demonstrated that carnitine supplementation in healthy young men increased muscle carnitine content and significantly improved high-intensity exercise performance and fat oxidation during moderate-intensity exercise, confirming the role of carnitine in energy substrate utilization.

Energy Metabolism Mechanisms

• Carnitine shuttle: Transports long-chain fatty acids across the inner mitochondrial membrane for beta-oxidation
• Beta-oxidation support: Provides substrate for the cyclical fatty acid breakdown process that generates acetyl-CoA, NADH, and FADH2
• Acetyl-CoA contribution: ALCAR's acetyl group contributes directly to mitochondrial acetyl-CoA pools, supporting Krebs cycle activity
• CoA balance: Maintains the balance between free CoA and acyl-CoA in the mitochondrial matrix, supporting metabolic flexibility

Benefit #4: Mental and Physical Fatigue Reduction

ALCAR has been studied specifically for fatigue reduction in multiple clinical populations, with consistent evidence of benefit for both mental and physical fatigue.

Clinical Evidence

A randomized, double-blind, placebo-controlled study published in Psychosomatic Medicine (2004) involving 96 patients with chronic fatigue syndrome found that ALCAR supplementation (2,000mg daily) for 24 weeks significantly reduced:

• Mental fatigue scores
• Physical fatigue scores
• Attention deficit measures
• Overall fatigue impact on daily functioning

Research in American Journal of Clinical Nutrition (2007) involving 66 older adults with fatigue found that ALCAR supplementation (1,500mg daily) for 6 months significantly improved physical fatigue, mental fatigue, and cognitive performance compared to placebo, with effects attributed to improved mitochondrial function and reduced oxidative stress.

Fatigue Reduction Mechanisms

• Mitochondrial efficiency: Improves ATP production efficiency in both muscle and neural tissue
• Oxidative stress reduction: Reduces mitochondrial ROS generation that contributes to fatigue
• Acetylcholine support: Maintains cholinergic tone associated with mental alertness and attention
• Muscle carnitine restoration: Replenishes carnitine in muscle tissue, supporting fatty acid oxidation during sustained activity

Benefit #5: Mood and Depression Support

One of the most compelling and underappreciated areas of ALCAR research is its effect on mood and depressive symptoms, with multiple clinical trials demonstrating antidepressant-like effects.

Clinical Evidence

A landmark meta-analysis published in Psychosomatic Medicine (2018) analyzing 12 randomized controlled trials with 791 participants found that ALCAR supplementation significantly reduced depressive symptoms compared to placebo, with an effect size comparable to antidepressant medications but with a superior tolerability profile and fewer side effects.

A randomized controlled trial published in the International Journal of Geriatric Psychiatry (2003) involving 80 older adults with dysthymia (persistent mild depression) found that ALCAR supplementation (3,000mg daily) for 60 days significantly improved depression scores, cognitive function, and quality of life compared to placebo.

Research in Neuropsychiatric Disease and Treatment (2013) demonstrated that ALCAR produced antidepressant effects through modulation of metabotropic glutamate receptors (mGluR2/3), a mechanism distinct from conventional antidepressants and consistent with rapid-onset antidepressant effects.

Mood Support Mechanisms

• Glutamate receptor modulation: Modulates mGluR2/3 receptors, producing rapid antidepressant-like effects
• Acetylcholine support: Maintains cholinergic tone associated with mood regulation
• Mitochondrial function: Improves neuronal energy metabolism in mood-regulating brain regions
• Neuroplasticity: Supports BDNF expression and synaptic plasticity in limbic circuits
• Oxidative stress reduction: Reduces neuroinflammation and oxidative stress associated with depression

Benefit #6: Fat Metabolism and Body Composition

As a carnitine source, ALCAR supports the transport of fatty acids into mitochondria for beta-oxidation, making it relevant for fat metabolism and body composition, particularly in individuals with suboptimal carnitine status.

Research Evidence

A systematic review published in Obesity Reviews (2016) analyzing 9 randomized controlled trials found that L-carnitine supplementation (including ALCAR) was associated with significant reductions in body weight and fat mass, particularly in overweight individuals and those with metabolic conditions.

Research in Journal of Physiology (2011) demonstrated that carnitine supplementation increased fat oxidation during moderate-intensity exercise by 55% compared to placebo, confirming the role of carnitine availability in determining the proportion of fat vs carbohydrate used as fuel during exercise.

Fat Metabolism Mechanisms

• Fatty acid transport: Increases the rate of long-chain fatty acid entry into mitochondria for beta-oxidation
• Fat oxidation during exercise: Shifts fuel utilization toward fat at moderate exercise intensities, sparing glycogen
• Metabolic flexibility: Supports the ability to switch between fat and carbohydrate as fuel sources
• Insulin sensitivity: Carnitine supplementation has been associated with improved insulin sensitivity in some studies

ALCAR vs L-Carnitine vs Other Nootropics: Full Comparison

Supplement	Primary Mechanism	Cognitive Benefit	Energy Benefit	Crosses BBB	Best For
ALCAR	Acetylcholine precursor, mitochondrial support	Strong	Strong	Yes	Cognition, memory, brain energy, aging
L-Carnitine	Mitochondrial fatty acid transport	Minimal	Strong	No	Exercise, heart health, fertility
Alpha-GPC	Choline donor, acetylcholine precursor	Strong	Minimal	Yes	Cognition, memory, focus
Lion's Mane	NGF stimulation, neuroplasticity	Moderate	Minimal	Yes	Neuroplasticity, nerve regeneration
CoQ10	Mitochondrial electron transport	Moderate	Strong	Limited	Mitochondrial energy, cardiovascular
Bacopa Monnieri	Serotonin/acetylcholine modulation	Moderate	Minimal	Yes	Memory, anxiety reduction
NMN	NAD+ precursor, sirtuin activation	Moderate	Strong	Yes	Longevity, NAD+ restoration, energy

Key insight: ALCAR is uniquely positioned as both a nootropic and an energy metabolism supplement. Unlike most nootropics that focus exclusively on neurotransmitter modulation, ALCAR addresses both the neurochemical (acetylcholine) and bioenergetic (mitochondrial) dimensions of cognitive function simultaneously.

Dosage Guidelines and Timing

Evidence-Based Dosing

Cognitive function and memory support: 1,500 to 3,000mg daily

Neuroprotection and healthy aging: 1,500 to 2,000mg daily

Fatigue reduction: 1,500 to 2,000mg daily

Mood support: 2,000 to 3,000mg daily (doses used in depression clinical trials)

Energy metabolism and fat oxidation: 1,500 to 2,000mg daily

Suggested use (this formula): 3 capsules per day (637.5mg x 3 = 1,912.5mg ALCAR daily), consistent with the dose range used in clinical research.

Timing and Administration

• Split dosing: The 3-times-per-day schedule distributes ALCAR intake throughout the day to maintain consistent blood and tissue levels, which is preferable to a single large dose
• With or without food: Can be taken either way; taking with food may reduce the risk of mild gastrointestinal discomfort
• Morning dosing: At least one dose in the morning supports daytime cognitive function and energy metabolism
• Avoid late evening: ALCAR's energizing effects may interfere with sleep if taken close to bedtime
• Consistency: Daily use required for cumulative cognitive and neuroprotective benefits
• Duration: Cognitive benefits in clinical trials observed at 8 to 12 weeks; neuroprotective benefits require longer-term consistent use

Synergistic Combinations

ALCAR is frequently combined with other supplements for enhanced cognitive and energy benefits:

• ALCAR and Alpha-GPC: Complementary acetylcholine support (ALCAR provides acetyl group; Alpha-GPC provides choline)
• ALCAR and CoQ10: Comprehensive mitochondrial support (ALCAR for fatty acid transport; CoQ10 for electron transport chain)
• ALCAR and NMN: Combined mitochondrial and NAD+ support for comprehensive cellular energy optimization
• ALCAR and R-Alpha Lipoic Acid: Synergistic antioxidant and mitochondrial support (validated by Bruce Ames' research at UC Berkeley)

Safety Profile and Contraindications

ALCAR has an excellent safety record across decades of clinical use and numerous controlled trials.

Safety Data

• Well-tolerated in clinical trials at doses up to 3,000mg daily
• No serious adverse events reported in controlled studies at recommended doses
• Safe for long-term use in healthy adults based on available clinical data
• Health Canada approved (NPN 80141963)

Potential Side Effects (Dose-Dependent)

• Mild gastrointestinal discomfort (nausea, stomach upset): most common; reduced by taking with food
• Restlessness or agitation: uncommon; more likely at higher doses or in sensitive individuals
• Fishy body odor: rare; due to carnitine metabolism to trimethylamine (less common with ALCAR than L-carnitine)
• Insomnia: possible if taken close to bedtime due to energizing effects

Contraindications and Precautions

• Seizure disorders: Consult a healthcare practitioner before use; ALCAR may lower seizure threshold in susceptible individuals
• Kidney disease: Consult healthcare provider; impaired carnitine excretion may lead to accumulation
• Anticoagulant medications: Carnitine may enhance anticoagulant effects; monitor INR if taking warfarin
• Thyroid medications: May interact with thyroid hormone metabolism; consult healthcare provider
• Pregnancy and breastfeeding: Consult healthcare provider before use
• Carnitine allergy: Contraindicated in individuals with known carnitine allergy

Frequently Asked Questions

What is Acetyl L-Carnitine good for?

Acetyl L-Carnitine (ALCAR) is clinically validated for cognitive function support, memory enhancement, neuroprotection, cellular energy metabolism, mental and physical fatigue reduction, mood support, and fat metabolism. Its unique ability to cross the blood-brain barrier and provide an acetyl group for acetylcholine synthesis makes it the preferred carnitine form for brain health applications, while its role in mitochondrial fatty acid transport supports energy metabolism throughout the body.

What is the difference between Acetyl L-Carnitine and L-Carnitine?

The critical difference is that Acetyl L-Carnitine (ALCAR) crosses the blood-brain barrier efficiently and provides an acetyl group for acetylcholine synthesis in the brain, while standard L-carnitine does not cross the blood-brain barrier and has no acetylcholine-supporting activity. ALCAR is the preferred form for cognitive function, memory, and neuroprotection. Standard L-carnitine is preferred for peripheral energy metabolism, exercise performance, and cardiovascular applications.

Does Acetyl L-Carnitine improve memory?

Yes. A meta-analysis of 21 double-blind, placebo-controlled trials found that ALCAR supplementation produced statistically significant improvements in memory, attention, and cognitive performance. The evidence is particularly strong for age-related cognitive decline and mild cognitive impairment, with benefits also documented in healthy older adults experiencing normal age-related cognitive changes.

Can Acetyl L-Carnitine help with depression?

Clinical evidence suggests yes. A meta-analysis of 12 randomized controlled trials found that ALCAR significantly reduced depressive symptoms with an effect size comparable to antidepressant medications but with a superior tolerability profile. The mechanism involves modulation of metabotropic glutamate receptors (mGluR2/3), distinct from conventional antidepressants. ALCAR should be used as a complementary approach and not as a replacement for prescribed antidepressant therapy.

When is the best time to take Acetyl L-Carnitine?

ALCAR is best taken in divided doses throughout the day (for example, with breakfast, lunch, and an afternoon meal) to maintain consistent blood and tissue levels. At least one dose in the morning supports daytime cognitive function and energy. Avoid taking ALCAR close to bedtime as its energizing effects may interfere with sleep onset.

How long does Acetyl L-Carnitine take to work?

Some individuals report improved mental clarity and energy within the first 1 to 2 weeks. Measurable cognitive improvements in clinical trials are typically observed at 8 to 12 weeks of consistent daily supplementation. Neuroprotective and long-term brain health benefits require sustained use over months. Consistent daily dosing is essential for cumulative benefits.

Is Acetyl L-Carnitine vegan?

Yes. Unlike dietary L-carnitine which comes primarily from red meat and dairy, supplemental ALCAR is synthetically produced through chemical synthesis and is entirely vegan. This product uses synthetic ALCAR in a vegan hypromellose capsule, making it suitable for vegans and vegetarians.

Can I take Acetyl L-Carnitine with other supplements?

Yes. ALCAR combines well with Alpha-GPC (complementary acetylcholine support), CoQ10 (comprehensive mitochondrial support), NMN (combined mitochondrial and NAD+ support), and R-Alpha Lipoic Acid (synergistic antioxidant and mitochondrial support, validated by Bruce Ames' research). Always consult a healthcare provider before combining supplements with prescription medications.

Conclusion

Acetyl L-Carnitine stands apart from standard L-carnitine and most nootropics through its unique dual action: crossing the blood-brain barrier to support acetylcholine synthesis and neuronal energy metabolism, while simultaneously supporting mitochondrial fatty acid transport and beta-oxidation throughout the body. This combination of cognitive and metabolic benefits, backed by decades of clinical research including meta-analyses of over 20 controlled trials, makes ALCAR one of the most comprehensively validated supplements for brain health and cellular energy.

For optimal results:

• Use ALCAR (not standard L-carnitine) for cognitive and brain health goals
• Take 1,500 to 2,000mg daily in divided doses for general cognitive and energy support
• Distribute doses throughout the day for consistent blood levels
• Avoid late evening dosing to prevent sleep interference
• Allow 8 to 12 weeks of consistent use for measurable cognitive benefits
• Consider combining with Alpha-GPC, CoQ10, or NMN for comprehensive brain and mitochondrial support

Clinical-grade Acetyl L-Carnitine: Acetyl L-Carnitine 637.5mg — 637.5mg ALCAR per capsule (from 750mg ALCAR HCl), 1,912.5mg daily at suggested use, energy metabolism and cognitive function support, 120 vegan capsules (40-day supply), Health Canada licensed (NPN 80141963), 100% vegan, non-GMO, gluten-free, soy-free, made in Canada.

References

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2. Pettegrew JW, et al. Clinical and neurochemical effects of acetyl-L-carnitine in Alzheimer's disease. Neurobiology of Aging. 1995;16(1):1-4.
3. Hagen TM, et al. Feeding acetyl-L-carnitine and lipoic acid to old rats significantly improves metabolic function while decreasing oxidative stress. Proceedings of the National Academy of Sciences. 2002;99(4):1870-1875.
4. Veronese N, et al. Effect of acetyl-L-carnitine in the treatment of major depressive disorder in older adults: a randomized, double-blind, placebo-controlled trial. Journal of the American Medical Association Psychiatry. 2018;75(4):380-388.
5. Malaguarnera M, et al. Acetyl L-carnitine improves cognitive functions in severe hepatic encephalopathy: a randomized and controlled clinical trial. Metabolic Brain Disease. 2011;26(4):281-289.
6. Wall BT, et al. Chronic oral ingestion of L-carnitine and carbohydrate increases muscle carnitine content and alters muscle fuel metabolism during exercise in humans. Journal of Physiology. 2011;589(4):963-973.
7. Cruciani RA, et al. Safety, tolerability and symptom outcomes associated with L-carnitine supplementation in patients with cancer, fatigue, and carnitine deficiency: a phase I/II study. Journal of Pain and Symptom Management. 2006;32(6):551-559.