What Is Norepinephrine?
You may have just landed here from one of our previous articles on the function and effects of norepinephrine. If so, then you know that norepinephrine is a catecholamine neurotransmitter involved in the fight or flight response. If not, you may want to brush up on the basics of norepinephrine before you read on.
The leading cause of norepinephrine deficiency is a genetic disorder called dopamine beta hydroxylase (DBH) deficiency. At least six variations in the DBH gene can cause this disorder, with the most common being the C allele at rs74853476 [1, 2, 3].
Dysfunctional DBH causes norepinephrine deficiency because this enzyme converts dopamine into norepinephrine. A person must have two abnormal versions of DBH to be genetically deficient in norepinephrine [1, 2, 3].
People with DBH deficiency may be prescribed droxidopa to manage their blood pressure. Droxidopa is converted to norepinephrine not by DBH, but by another enzyme called L-aromatic amino acid decarboxylase .
Symptoms of DBH Deficiency
People with DBH deficiency have difficulty regulating their body temperature and blood pressure. The condition is often discovered in late childhood as symptoms develop: vomiting, dehydration, low blood pressure, and low blood sugar are common .
Low blood pressure has its own complications, among them dizziness, blurred vision, and difficulty exercising. Some people with DBH deficiency may have more severe symptoms, including :
- High palate
- Low blood sugar at birth
- Frequently waking at night to urinate
- Sudden drops in blood pressure when standing up
- Drooping eyelids
- Retrograde ejaculation, which may lead to infertility 
- Seizures, possibly due to a lowered seizure threshold 
- High insulin levels and insulin resistance 
People with DBH deficiency have, on average, smaller brain volume than the average population. Fortunately, however, their brain function is largely intact, with no evidence of cognitive delay. Some researchers speculate that other neurotransmitters, such as dopamine, take over the function of norepinephrine in this population .
Congenital Insensitivity to Pain with Anhidrosis
It’s a mouthful: congenital insensitivity to pain with anhidrosis, or CIPA, is a condition marked by the inability to feel pain or to sweat. Norepinephrine is not part of the diagnostic criteria of the disease; however, children with CIPA have extremely low – sometimes completely undetectable – levels of norepinephrine [10, 11].
Drugs that Reduce Norepinephrine
Some medications reduce blood pressure and decrease norepinephrine. These include clonidine, prazosin, terazosin, atenolol, metoprolol, and propranolol. Reducing norepinephrine is usually the intended result of taking these drugs; however, if the dosage is too high, this neurotransmitter (and, thus, blood pressure) can be lowered to a dangerous degree [12, 13, 14].
Positive Effects of Norepinephrine
Norepinephrine has many crucial effects in the brain and body. Deficiency might affect its ability to perform any of its functions listed below.
1) Improves Mood
We’re always looking for benefits that don’t need a lab test – benefits that we can really feel in our daily lives – and here’s one! Norepinephrine can regulate emotions, fight depression, and improve mood.
Norepinephrine increases vigilance, arousal, attention, motivation, reward, learning, and memory .
Catecholamines and Depression
Catecholamines have been implicated in depression since the 1960s. At the time, the “catecholamine hypothesis of affective disorders” was highly controversial.
Researchers have since developed many hypotheses about brain chemistry and depression; however, it is broadly accepted that people with low catecholamines, including dopamine and norepinephrine, are more likely to be depressed [16, 17, 18, 19, 20].
That’s why some of the most common antidepressant medications are serotonin and norepinephrine reuptake inhibitors, or SNRIs. These medications stop serotonin and norepinephrine from re-entering the neuron, leaving more of them available and effective for longer [21, 22].
These SNRIs may be more effective antidepressants than the selective serotonin reuptake inhibitors, or SSRIs .
2) Helps Memory and Cognitive Function
Norepinephrine released by the locus coeruleus affects brain function in a number of ways.
It enhances sensory processing, attention, and the formation and retrieval of both long-term and working memory. Norepinephrine is necessary for access to a memory and is important for consolidation and retrieval of some types of memory [24, 25, 26].
Loss of norepinephrine function may partially cause, or at least worsen, Parkinson’s disease. Activity in the locus coeruleus – which is full of norepinephrine – may stimulate and protect the substantia nigra, the part of the basal ganglia that deteriorates during Parkinson’s. If the locus coeruleus fires at a decreased rate, the substantia nigra may become more sensitive to toxic agents and die off more quickly [33, 34].
One of the earliest signs of Parkinson’s disease is decreased attention and focus. This, along with the decreased activity of the locus coeruleus, implicates norepinephrine in the development of this disease .
Because the attentional symptoms precede the motor symptoms of Parkinson’s, some researchers are investigating norepinephrine as an early intervention .
3) Helps ADHD
Of course, if we’re going to talk about decreased attention and focus, we have to address ADHD. Norepinephrine increases alertness and lets us “dial in” to a task, challenge, or threat. In people with attention deficit hyperactivity disorder, the aforementioned ADHD, norepinephrine function is in disarray .
People with ADHD have irregular (but usually low) norepinephrine transmission to the α1 and α2 adrenoreceptors. In the healthy brain, norepinephrine regulates the “switch” between focus and flexibility. In the ADHD brain, this switch is poorly regulated; people with ADHD are usually distractible, with periods of intense “hyperfocus” in between [37, 38, 39, 40].
4) Chronic Fatigue Syndrome and Fibromyalgia
Chronic fatigue syndrome, or CFS, is a debilitating condition marked by long stretches of exhaustion with no obvious cause. People with CFS don’t have a healthy response to physical exercise or exertion: where the average person’s norepinephrine levels would rise, theirs stay low .
The role of norepinephrine in CFS and fibromyalgia is unclear. While it appears to stay low during exercise, medications that increase norepinephrine may not be helpful.
Serotonin and norepinephrine reuptake inhibitors (SNRIs) like duloxetine do not improve symptoms of CFS. These medications have likewise had mixed results in fibromyalgia, with improvements in only a few patients [46, 47].
To further complicate things, a study of teenagers with CFS actually found that they had a higher baseline level of norepinephrine. These results suggest that the system controlling norepinephrine response is dysfunctional in people with CFS .
Some people with CFS, and especially with fibromyalgia, may benefit from increasing norepinephrine. However, it is not a foolproof strategy.
5) May Help Bipolar Disorder
Bipolar disorder is a condition that causes swings or “switches” between manic and depressive episodes. People with bipolar disorder may have weeks or months of high energy, productivity, and good mood… followed by weeks or months of deep depression .
The exact cause of bipolar disorder is unknown, but people with the condition have lower levels of norepinephrine. Furthermore, antidepressants that increase norepinephrine have been successful treatment options .
Bupropion, which increases both norepinephrine and dopamine, is among the better antidepressants for people with bipolar disorder. It is also associated with a low frequency of switching between manic and depressive states [51, 52].
Interestingly, bupropion has better treatment outcomes than serotonin norepinephrine reuptake inhibitors (SNRIs). Plus, drugs that only affect norepinephrine may trigger mild to moderate manic episodes [51, 53].
Bipolar disorder is poorly understood. Researchers are still figuring out what causes it, how it progresses, and whether norepinephrine could be at the root.
6) Prevents Migraines
People with debilitating migraine headaches may have an imbalance of norepinephrine compared with other neurotransmitters. When a migraine begins, sufferers have relatively low norepinephrine and relatively high dopamine, prostaglandins, adenosine triphosphate, and adenosine [54, 55].
An enzyme called dopamine beta hydroxylase, or DBH, is responsible for converting dopamine into norepinephrine. Low levels or dysfunction of this enzyme would increase dopamine and decrease norepinephrine. This, in turn, would cause an imbalance of neurotransmitters, which may cause migraine in some people .
Serotonin and norepinephrine reuptake inhibitors, or SNRIs, are often used to prevent migraine. They are more effective than selective serotonin reuptake inhibitors (SSRIs), which suggests that they may work by restoring the balance between norepinephrine and dopamine .
7) May Promote Fat Loss
Increased norepinephrine has been linked to weight loss. In obese mice, intermittent fasting increased both norepinephrine and the rate of fat loss; however, it is unclear whether norepinephrine promoted weight loss in this study .
Future research will clarify this contradictory evidence regarding the role of norepinephrine in weight management.
How to Increase Norepinephrine
Your Favorite Things
Obviously, one shouldn’t seek out stressful experiences just to increase norepinephrine. The good news is: you don’t have to!
According to a rat study, norepinephrine increases in response to strong stimuli – both positive and negative. Animal and human studies confirm that powerful emotions of all kinds trigger norepinephrine release. That means that any experience that makes you feel strongly (and requires a lot of brain power to process) may increase norepinephrine [60, 61].
Foods and Diet
Caffeine triggers the release of norepinephrine from the locus coeruleus. Foods containing caffeine – coffee, chocolate, soda, energy drinks – may, therefore, increase norepinephrine levels. Some foods and drinks that contain caffeine, such as green tea, will not increase norepinephrine because they contain other compounds that counteract caffeine [62, 59, 63].
Norepinephrine itself is currently only available by prescription as a drug called levophed. However, some commercially available supplements and supplement combinations have been shown to increase norepinephrine production in the body .
Alone, neither bitter orange nor Rhodiola rosea increase norepinephrine; in fact, they may decrease it. However, in combination, these two supplements significantly increased norepinephrine in rats .
At least one commercial weight loss supplement – a combination of yohimbine, caffeine, and synephrine – has been found to increase norepinephrine. Yohimbine alone also increases norepinephrine in the blood [71, 72, 73].
In summary, if you want to increase norepinephrine with herbal supplements, these may work:
- Combined bitter orange and rhodiola
- Yohimbine, an alkaloid from an African tree’s bark
- Combined yohimbine, caffeine, and synephrine
- Combined caffeine and bitter orange
Norepinephrine biosynthesis starts with either of two amino acids: phenylalanine and tyrosine. Supplementing with these compounds may increase the amount of norepinephrine your body can make. Note that some research contradicts this hypothesis, and not all researchers agree that dietary protein increases catecholamines [75, 76, 77].
Mucuna pruriens, or velvet bean, is a legume that grows in tropical climates. The bean contains very high concentrations of L-dopa, a precursor to dopamine and norepinephrine. In rats, mucuna restored normal levels of catecholamines, including norepinephrine, in the brain [78, 79].
Catechol-O-methyltransferase, or COMT, breaks down catecholamines, including norepinephrine. Any substance that blocks COMT may, therefore, increase norepinephrine. These include quercetin, fisetin, and green and black tea extracts [80, 81, 82, 81].
Acetylcarnitine, also called acetyl-L-carnitine or ALCAR, is a common commercial supplement sold with claims of improving muscle strength and energy. In mice, acetylcarnitine increases norepinephrine in the hippocampus of the brain .
Over a period of several days, exercise increases available norepinephrine. In mice, exercise reduced the number of norepinephrine transporters in the brain, which allows more of this neurotransmitter to stay outside the neurons .
In this way, exercise acts as a norepinephrine reuptake inhibitor – but not right away. If you want to use exercise to increase norepinephrine, you’ll need to stick to your fitness plan for days, weeks, and months at a time .
Exercise and cold temperatures have both been found to increase norepinephrine turnover: that is, the rate at which the sympathetic nervous system releases and uses norepinephrine. In rats, cold exposure also decreases norepinephrine reuptake after the event, which may leave more of this neurotransmitter available in the blood in the longer term [85, 86, 87].
A number of drugs, medical and otherwise, increase norepinephrine. This list is by no means comprehensive.
We do not promote using these compounds to increase catecholamines; this section is here to provide information to people already taking these drugs on the advice of their doctors.
However, this is an addictive drug which poses significant risks to people’s health and wellbeing. Furthermore, when people stop taking nicotine (either in cigarettes or by other means), their norepinephrine levels spike and then drop. In adolescents, this drop is associated with long-term risks of heart disease .
Tetrahydrobiopterin, or BH4, is a natural compound that is required for the human body to make neurotransmitters like norepinephrine. It is also available as a prescription medication for phenylketonuria. It increases the conversion of phenylalanine into tyrosine, which can then be converted into the catecholamines, including norepinephrine [95, 96, 97].
Tianeptine is an antidepressant that activates opioid receptors, restores BDNF, and increases serotonin and norepinephrine in the spinal cord. Tianeptine may also increase norepinephrine in certain parts of the brain and decrease it in others [98, 99, 100, 101, 102].
This article is the second of a three-part series:
Norepinephrine must stay in balance for the brain and body to stay healthy. Too little has been linked to low blood pressure, distractibility, and migraine. Norepinephrine is also lacking in some people with depression, and increasing it can improve low mood and other symptoms.
It is important for memory and cognitive function; low levels are involved in Alzheimer’s, Parkinson’s, and ADHD. People with chronic fatigue syndrome and fibromyalgia have poorly regulated norepinephrine systems. Low norepinephrine has also been tied to bipolar disorder and migraines.
Keep a close eye on these symptoms to find out whether you may need to increase norepinephrine.
Low norepinephrine can also be caused by genetic disorders, like DBH deficiency and CIPA, or by external factors like blood pressure drugs.
You can increase norepinephrine by eating foods high in protein and caffeine, using supplements like mucuna or yohimbine, or simply by doing activities you enjoy.