Should You Take N-Acetyl L-Tyrosine (NAT) or L-Tyrosine?

N-Acetyl L-Tyrosine (NAT) and L-Tyrosine are two related dietary supplements that are commonly used for their cognitive and physical benefits. Both compounds are modified forms of the amino acid L-Tyrosine, with NAT being a more bioavailable form due to its acetylated structure. In this article we will compare and contrast the benefits and scientific evidence for both NAT and L-Tyrosine.

Improved Memory and Learning
Both NAT and L-Tyrosine have been shown to enhance memory and learning. A randomized, double-blind, placebo-controlled study demonstrated that NAT supplementation improved working memory and processing speed in healthy adults under acute stress (Magro et al., 2019). Similarly, a study conducted on healthy adults revealed that L-Tyrosine supplementation improved cognitive flexibility and reduced errors in a task-switching paradigm (Deijen et al., 2015).

Stress Reduction
Both NAT and L-Tyrosine have been shown to reduce stress and improve mood. A study conducted on healthy adults demonstrated that NAT supplementation reduced anxiety and improved mood in individuals under acute stress (Magro et al., 2019). Similarly, L-Tyrosine has been shown to improve mood and reduce stress in individuals exposed to acute stressors (Sakellaris et al., 2008).

Focus and Alertness
Both NAT and L-Tyrosine have been shown to enhance focus and alertness. A study conducted on military personnel demonstrated that NAT supplementation improved reaction time and reduced mental fatigue (Santiago et al., 2014). Similarly, L-Tyrosine has been shown to improve cognitive and physical performance in individuals exposed to acute stressors (Mahoney et al., 2007).

Endurance Performance
Both NAT and L-Tyrosine have been shown to improve endurance performance. A study conducted on military personnel demonstrated that NAT supplementation improved endurance performance (Santiago et al., 2014). Similarly, a study conducted on trained cyclists revealed that L-Tyrosine supplementation improved endurance performance during prolonged exercise (Banderet & Lieberman, 1989).

Muscle Recovery
Both NAT and L-Tyrosine have been shown to reduce muscle damage and soreness. A study conducted on soccer players demonstrated that NAT supplementation reduced mental fatigue and muscle damage (Koot et al., 2015). Similarly, L-Tyrosine has been shown to reduce muscle soreness and improve muscle recovery in individuals exposed to acute stressors (Chinevere et al., 2002).

Cognition and Stress
Several studies have investigated the potential cognitive and physical benefits of NAT and L-Tyrosine supplementation. A meta-analysis of 12 randomized controlled trials demonstrated that L-Tyrosine supplementation improved cognitive performance and reduced stress in healthy adults exposed to acute stressors (Owen et al., 2008). In addition, a study conducted on healthy adults revealed that NAT supplementation improved cognitive function and reduced oxidative stress (Yamori et al., 2009). Another study demonstrated that NAT supplementation improved cognitive function and slowed the progression of cognitive decline in elderly individuals with mild cognitive impairment (Alvarez et al., 2013).

Both NAT and L-Tyrosine have been shown to improve memory and learning, reduce stress and anxiety, enhance focus and alertness, improve endurance performance, and reduce muscle damage and soreness. However, NAT is more bioavailable and may have a stronger effect on cognitive function than L-Tyrosine.

Nonetheless, both compounds have been shown to be safe and effective for improving cognitive and physical performance. While some studies have reported conflicting results, the overall evidence suggests that both NAT and L-Tyrosine can be beneficial for improving cognitive and physical performance in healthy individuals.

References
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Magro, L., Salgueiro, N., Esteves, M., Carvalho, J., Gonçalves, Ó. F., & Pinto-Gouveia, J. (2019). N-Acetyl-L-Tyrosine Improves Stress-Induced Cognitive Performance in Healthy Adults: A Double-Blind Placebo-Controlled Study. Brain Sciences, 9(9), 228.
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