L-Serine Guide (+ Top 3 Supplements)

L-serine is an amino acid that plays a role in the function of the nervous system, including the brain. It’s a nonessential amino acid, meaning it is produced within the body. However, the body doesn’t produce enough l-serine on its own, so it’s important to get enough via diet or supplementation.¹Phosphoserine Aminotransferase Deficiency: A Novel Disorder of the Serine Biosynthesis Pathway

In this guide:

• The top 3 l-serine supplements
• L-serine benefits
• L-serine dosage

Top 3 L-Serine Supplements

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L-Serine Benefits

More research on l-serine is needed, but there have been some interesting findings on this amino acid thus far.

Research has found a correlation between low levels of l-serine and decreased cognitive function.²l-Serine synthesis in the central nervous system: A review on serine deficiency disorders These low-l-serine deficits can include the following:³An update on serine deficiency disorders⁴Treatment with amino acids in serine deficiency disorders⁵Continuing Education in Neurometabolic Disorders – Serine Deficiency Disorders⁶l-Serine in disease and development

Effects of Low L-Serine Levels

• Decreased psychomotor skills (i.e., hand-eye coordination, dexterity, fine manipulation, etc.)
• Increased risk of seizures
• Polyneuropathy (nerve damage resulting in numbness, weakness, and/or pain)
• Psychiatric disorders

L-serine is required to produce compounds vital to proper brain function, including certain phospholipids and neurotransmitters.⁷Serine-deficiency syndromes Neurotransmitters are chemicals involved in relaying signals among nerve and muscle fibers. Phospholipids, a component of cell membranes, sometimes play a similar role.

L-Serine vs. D-Serine

Research has shown that d-serine may help support the brain and nervous system, as discussed below. But what’s the difference between l-serine and d-serine?

L-serine is converted into d-serine in glial cells surrounding neurons. However, taking d-serine directly as a supplement may not be safe. It is not classified as a Generally Regarded as Safe substance by the FDA, while l-serine is. Research on supplementing d-serine directly is limited.

Taking all of this into account, most people looking to supplement serine will opt for l-serine, since it’s converted to d-serine anyway and is regarded as safe to supplement.

Benefits of L-Serine’s Byproduct: D-Serine

Studies have identified a handful of potential effects and benefits of d-serine, the product of l-serine.

• Potential Memory Improvement

Research has shown that increased d-serine levels may support mechanisms associated with memory.⁸Long-term potentiation depends on release of D-serine from astrocytes

• Potential Neuron Signaling Improvement

Research has demonstrated that d-serine plays a vital role in supporting certain neurotransmitters.⁹Glia-Derived d-Serine Controls NMDA Receptor Activity and Synaptic Memory In turn, neurotransmitters play a role in transmitting signals throughout the body’s nervous system, including the brain.

• Potential Impact on Schizophrenia Symptoms

Several studies found that supplementing d-serine reduced symptoms of schizophrenia in most subjects.¹⁰D-serine added to antipsychotics for the treatment of schizophrenia¹¹D-serine efficacy as add-on pharmacotherapy to risperidone and olanzapine for treatment-refractory schizophrenia¹²High dose D-serine in the treatment of schizophrenia It’s very important to note that d-serine was taken alongside the patients’ usual anti-psychotic medication. A regimen of d-serine alone against schizophrenia symptoms has not been studied.

L-Serine and Alzheimer’s Disease

The little research that has been performed on l-serine and Alzheimer’s disease thus far is unclear and conflicting.

One study found that levels of d-serine (a product of l-serine) were higher in patients with Alzheimer’s disease than in control subjects.¹³D-serine levels in Alzheimer’s disease: implications for novel biomarker development Another study found that levels of d-serine were lower in patients with Alzheimer’s disease.¹⁴Possible role of d-serine in the pathophysiology of Alzheimer’s disease The same study found that l-serine levels were higher in Alzheimer’s disease patients.

As it currently stands, research does not support l-serine supplementation as a means to impact Alzheimer’s disease symptoms.

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L-Serine Dosage

There is currently no official recommended l-serine dosage. However, several studies have found that an l-serine dosage of up to 400 milligrams per kilogram of bodyweight per day is likely safe.¹⁵Clinical and metabolic consequences of L-serine supplementation in hereditary sensory and autonomic neuropathy type 1C¹⁶L-Serine Supplementation in Hereditary Sensory Neuropathy Type 1

L-serine dosages can be broken up throughout the day or taken all at once. There is no research to suggest timing of an l-serine dosage is important. They can be taken either with or in between meals.

L-Serine Side Effects

At an l-serine dosage of up to 400 milligrams per kilogram of bodyweight per day, studies have not noted any significant side effects. Some individual users have reported upset stomach and/or diarrhea, but this has not been widely found in studies.

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Summary

L-Serine supplements may be considered as a way to support brain and nervous system function. However, while the current data is promising, more research on this amino acid is needed.

There are more thoroughly-studied supplements that have been shown to support cognitive health and performance, such ashwagandha and rhodiola. These may be better alternatives for some people.