Norepinephrine | SLC18A1 (rs1390938)

Last reviewed: May 12, 2026 Last updated: May 12, 2026

Written by: Jay Hastings , CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance. His work has included scaling healthcare startups, leading CLIA lab integrations, and helping expand consumer access to precision health tools.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

The SLC18A1 rs1390938 (VMAT1) Variant and Monoamine Balance: What Your Genotype May Mean for Stress Resilience, Energy, and Mood

Your brain and body rely on a steady supply of chemical messengers called neurotransmitters. A key group of these messengers - called monoamines - includes norepinephrine, epinephrine, dopamine, and serotonin. They help shape everyday experiences like alertness, attention, motivation, stress response, mood stability, and even how steady your energy feels across the day.

The SLC18A1 gene encodes VMAT1 (vesicular monoamine transporter 1), a “packaging” protein that loads monoamine neurotransmitters into storage vesicles inside cells. Think of VMAT1 as part of the system that prepares neurotransmitters for controlled release. When packaging is efficient, signaling can be steadier and more predictable. When packaging is less efficient, signaling may be less stable - especially during high-demand situations like stress, poor sleep, or inconsistent eating patterns.

What VMAT1 Does and Why It Matters

VMAT1 helps move monoamines - especially norepinephrine, epinephrine, dopamine, and serotonin - into vesicles so they can be stored and released in a controlled way. This matters because neurotransmitter signaling is not just about how much you make, but how consistently you can store and release it. VMAT1 is expressed in the brain and in endocrine tissues, including areas tied to stress physiology. VMAT1 also contributes to serotonin handling in the gut, which is one reason gut patterns and stress physiology can show up together in day-to-day energy, mood stability, and brain fog.

Norepinephrine is especially relevant when talking about VMAT1. It supports alertness, attention, stress resilience, and energy regulation. When norepinephrine signaling feels “steady,” people often describe more consistent focus and fewer crashes. When signaling is less stable, some people notice a “wired then drained” pattern, more sensitivity to stress, or mood variability - especially when lifestyle inputs (sleep, meals, and stress load) are inconsistent.

The rs1390938 Variant: A Functional Change in VMAT1 Activity

One commonly researched SLC18A1 variant is rs1390938 (Thr136Ile). This SNP has been studied in relation to VMAT1 transport efficiency and has also shown associations in research with mood and psychiatric traits. In some studies, higher VMAT1 activity has been linked to lower risk of several anxiety-, affective-, and alcohol-related outcomes compared with lower-activity patterns. However, individual outcomes vary widely, and day-to-day habits can meaningfully shape how these pathways feel in real life.

Practical Steps for Everyone: A “VMAT1-Friendly” Foundation

Regardless of genotype, the most helpful strategy is to support stable monoamine signaling by keeping blood sugar steady, supporting mitochondrial energy, lowering inflammation, and maintaining a gut pattern that supports healthy serotonin handling. A practical template is Mediterranean/MIND-style eating: vegetables at most meals, berries several times per week, legumes and whole grains for fiber, olive oil, nuts and seeds, and fish - while limiting ultra-processed foods and frequent high-sugar snacks that can trigger energy crashes and irritability.

• Build steady meals: Combine protein + fiber + slow carbs to avoid sharp spikes and dips in energy.
• Prioritize protein at breakfast: A consistent morning protein anchor can support steadier focus and fewer mid-morning crashes.
• Use fiber as a “stability tool”: Aim for a high-fiber pattern to support gut health and more even energy.
• Be thoughtful with alcohol: Keeping alcohol modest (and away from bedtime) is a high-ROI move for mood stability, sleep quality, and next-day cognition.

Supplements and Nutrients to Consider (Steady Support, Not Overdrive)

For VMAT1-related patterns, supplements are most useful when they improve sleep and stress recovery, reduce inflammatory load, and correct common nutrient gaps that can look like mood or attention issues. Many people start with foundations that have a strong risk/benefit profile, especially when diet quality is inconsistent.

• Omega-3s (EPA + DHA): Consider if you do not eat fatty fish 2–3 times per week.
• Magnesium: Often used in the evening (many people prefer glycinate at night) to support relaxation and sleep quality.
• Vitamin D: Consider when sun exposure is low, ideally guided by labs.

If symptoms like fatigue, brain fog, or mood volatility are present, labs-first essentials are often the biggest win. Consider discussing B12, folate, ferritin/iron status, and (when relevant) thyroid markers with a clinician, because deficiencies or hormonal dysregulation can feel like “neurotransmitter imbalance,” and correcting them can produce the most reliable improvement.

Because monoamine-related genes have been studied in psychiatric vulnerability contexts, it is wise to avoid a “kitchen sink” approach that stacks multiple neurotransmitter-active supplements at once - especially for people with a personal or family history of bipolar disorder, severe anxiety, or psychosis-spectrum symptoms. If you want a gentle add-on for calm focus or mental energy, many people trial one option at a time (for example, L-theanine for smoother calm-focus or creatine monohydrate for mental energy buffering) for 3–6 weeks while tracking sleep quality, irritability, focus stamina, and crash frequency.

If you are considering serotonin precursors (like 5-HTP) or stimulating adaptogens, it is safer to do so with clinician guidance. With monoamines, “more” is not always better.

Genetic Interpretations for rs1390938 (SLC18A1 / VMAT1)

Lifestyle Recommendations: Highest ROI for VMAT1 Pathways

VMAT1 supports reliable monoamine release, so your lifestyle goal is predictable inputs that keep norepinephrine, dopamine, and serotonin signaling steady: regular sleep, regular movement, and regular stress downshifts.

• Sleep timing: Keep a consistent wake time, get bright light within an hour of waking, and protect a 60–90 minute wind-down with lower stimulation.
• Caffeine timing: Limit caffeine to earlier in the day; fragmented sleep can worsen anxiety, irritability, and brain fog regardless of genotype.
• Exercise as a “monoamine stabilizer”: Aim for steady weekly movement (Zone 2 cardio plus resistance training) to support stress resilience, metabolic flexibility, sleep depth, and inflammation balance.
• Daily downshift: Add 5–10 minutes of a parasympathetic practice (slow breathing, mindfulness, gentle yoga, or a walk without your phone).
• Environmental guardrails: Make routines easier - phone out of the bedroom, scheduled breaks, fewer late-night decisions, and repeatable meal templates.

When to Talk to Your Healthcare Provider

If you have persistent concerns about mood stability, anxiety, sleep disruption, attention changes, or energy crashes, talk with a healthcare provider. They can help interpret symptoms in context, consider labs that commonly affect energy and mood (such as B12, folate, ferritin/iron status, vitamin D, and thyroid markers when relevant), and guide safer choices if you are considering neurotransmitter-active supplements - especially if there is a personal or family history of bipolar disorder, severe anxiety, or psychosis-spectrum symptoms.

PlexusDx does not provide medical advice. This information is educational and intended to help you understand how SLC18A1 (VMAT1) genetics may relate to neurotransmitter balance, stress resilience, and steady energy. Always consult your healthcare provider before making changes to your diet, supplement routine, or exercise plan, or if you have concerns about your health.

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If this genetic variant is present in your PlexusDx results, the following tests and reports are commonly used to explore it further:

🧬 Genetic Tests:

• Functional Health Genetic Test

🧪 Blood Tests:

• Women's Health and Wellness Blood Test
• Men's Health and Wellness Blood Test

📄 Genetic Report:

• Cognition and Brain Health Genetic Report

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Frequently Asked Questions About Norepinephrine and SLC18A1 rs1390938

What does the SLC18A1 rs1390938 (VMAT1) variant mean for stress resilience and mood?

The SLC18A1 rs1390938 variant affects VMAT1, a protein that packages key monoamine neurotransmitters (norepinephrine, dopamine, and serotonin) for steady storage and release. Genotypes associated with reduced VMAT1 transport efficiency may lead to less stable monoamine signaling, which can show up as heightened sensitivity to stress, mood variability, or “wired then drained” patterns—especially when sleep, meals, or stress are inconsistent. Individual responses vary, and lifestyle consistency is a major driver of outcomes.

How can I support monoamine balance if I have the VMAT1 rs1390938 effect allele?

To support steadier neurotransmitter signaling, focus on predictable inputs: keep blood sugar stable with meals that include protein + fiber + slow carbs; prioritize protein at breakfast; aim for a high-fiber gut-supporting pattern; limit ultra-processed foods and frequent high-sugar snacks; and keep alcohol modest. Consistent sleep timing, earlier-in-the-day caffeine, and regular movement (such as Zone 2 cardio plus resistance training) also support stress recovery and more reliable energy and attention.

Are supplements helpful for the SLC18A1 (VMAT1) rs1390938 genotype?

Supplements can be useful when they improve sleep, reduce inflammatory load, or address nutrient gaps that may mimic or worsen mood and attention symptoms. Common starting points include omega-3s (EPA + DHA) if you don’t eat fatty fish 2–3 times per week, magnesium in the evening to support relaxation and sleep, and vitamin D if sun exposure is low (ideally guided by labs). If you have fatigue, brain fog, or mood volatility, labs-first nutrient and thyroid/iron-related checks (such as B12, folate, ferritin/iron, vitamin D, and thyroid markers when relevant) can be more impactful than stacking multiple neurotransmitter-active supplements.

What tests can help me learn more about Norepinephrine and SLC18A1 rs1390938?

The Cognition and Brain Health Genetic Test delivers over 120 genetic insights related to neurotransmitter regulation, neuroplasticity, cognitive resilience, and healthy aging. The Cognition and Brain Health Genetic Report translates your results into personalized, actionable guidance. Your healthcare provider can also recommend targeted blood tests based on your specific pathway results and health history to complement your genetic insights with current biomarker data.

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Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance. References are included at the end of the article when scientific, medical, or health-related claims are discussed.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.