Melatonin And Blood Pressure: Everything To Know

12/22/2021 | 6 min. read

Healthy Directions Staff Editor

Healthy Directions Staff Editor

Melatonin is the go-to supplement when it comes to natural sleep aids.

In terms of overall health, getting a good night’s rest ranks at the top. But, when counting sheep doesn’t work, many turn to natural sleep aids, such as the one mentioned above.

Melatonin is the body’s master sleep hormone and is produced naturally by the body. It plays a regulatory role when it comes to the body’s sleep-wake cycle.

The efficacy of melatonin when it comes to sleep health is proven. But, many are unaware of the effects it has on another important function — blood pressure.

A Brief Look at Melatonin

Aside from being a sleep aid, melatonin is a naturally occurring hormone. It is the sleep hormone. Melatonin helps control the circadian rhythm of the body, also referred to as the sleep-wake cycle.

The sleep-wake cycle can be thought of as our body’s internal clock, set to 24-hour cycles. Melatonin helps support and maintain normal sleep patterns.

How Melatonin Works

Melatonin is produced by the pineal gland within the brain and released into the bloodstream. It is produced in response to light exposure.

The pineal gland is controlled by a complicated group of neurons and nerve cells known as the suprachiasmatic nucleus (SCN). This network helps maintain melatonin levels within the body.

Melatonin levels fall during the day when we are exposed to sunlight. In brief, when sunlight is absorbed through the retina of the eyes, the SCN tells the pineal gland to slow melatonin production.

When light diminishes throughout the day, the process begins to reverse as we are exposed to darkness. Then, melatonin levels start to rise. This is why we start feeling more and more sleepy as the night wears on.

Sustained levels of melatonin throughout the night ensure we get deep, restful sleep. Under normal conditions, healthy people usually have a ten pg/mL melatonin blood level during the daytime; nighttime levels spike to 150 pg/mL.

The Benefits of Melatonin Supplements

Under normal conditions, the body can produce sufficient amounts of melatonin. But, the normal production of melatonin does tend to decrease as we age. Other reasons for low melatonin levels might include: Not getting enough natural light during the day, excessive blue light exposure (computers, phones, tablets), and lifestyle factors (e.g., night shift work).

Melatonin supplements can help improve sleep health by:

  • Restoring a healthy sleep-wake cycle – Using melatonin can help re-establish a proper circadian rhythm.
  • Helping you fall asleep – Taking melatonin an hour before bed can help prepare your body for sleep, helping you wind down and fall asleep faster.
  • Reducing restlessness and nighttime waking – Supplemental melatonin helps reduce restlessness by raising natural melatonin levels, improving your chances of staying asleep.

Melatonin and Blood Pressure?

The benefits of supplementing melatonin to improve sleep are well understood. However, most don’t suspect melatonin as being a supplement to help reduce blood pressure. But the research findings may surprise you.

A Look at Blood Pressure

Blood pressure is one way to tell how hard your heart is working. Blood pressure is the force of your blood that pushes against the walls of your arteries. Of course, arteries are essential for carrying oxygenated blood from the heart to the other organs and tissues throughout the body.

Blood pressure is measured in millimeters of mercury (mm Hg). Most people are familiar with getting their blood pressure checked at their doctor’s office; it is a routine procedure to evaluate heart health and function. It is measured with two numbers.

Systolic Blood Pressure

Systolic blood pressure refers to the top number of the blood pressure reading. This measures the pressure or force of blood against the heart’s arterial walls when your heart beats.

Diastolic Blood Pressure

The diastolic blood pressure is the second or bottom number of the blood pressure reading. When the heart relaxes in between beats, the ventricles fill with blood; the diastolic reading measures the pressure in your arteries when the heart is at rest in between these beats.

Per the American Heart Association, adult blood pressure measurement ranges are as follows:

  • Normal Blood Pressure: Systolic less than 120 and diastolic less than 80
  • Elevated Blood Pressure: Systolic 120 - 129 and diastolic less than 80
  • Stage 1 Hypertension: Systolic 130 - 139 or diastolic 80 - 89
  • Stage 2 Hypertension: Systolic 140 or higher or diastolic 90 or higher
  • Hypertensive Crisis: Systolic higher than 180 or diastolic higher than 120

So, under ideal conditions, a normal blood pressure reading would be less than 120/80 mm Hg. Keep in mind, extremely low blood pressure can also be a cause of concern.

Hypertension

High blood pressure (HBP) is also known as hypertension, as noted by the ranges above. Chronic hypertension can put you at risk for severe health conditions like heart issues, heart attack, and stroke. Nearly half of U.S. adults have hypertension.

Aside from the serious risk factors mentioned above, hypertension can also cause headaches, dizziness, shortness of breath, chest pain or tightness, and more. Hypertension can be brought on by genetics, poor diet, obesity, diabetes, and other lifestyle factors.

Managing Hypertension

Depending on the severity, and other factors, hypertension can be managed through prescription medications. But, it can also be managed naturally in some cases. For example, lowering diastolic blood pressure through a healthy heart diet is not uncommon.

A reduction in sodium consumption has also been shown to help lower blood pressure; normal sodium intake should be less than 2,500 mg a day. Limiting caffeine and alcohol intake is another lifestyle choice that can help reduce blood pressure. Both tend to raise blood pressure when used in excess.

Furthermore, there are dietary supplements that can help reduce blood pressure; melatonin could be among them.

The Melatonin Connection

Blood pressure levels tend to naturally fluctuate many times within 24 hours. The highest tends to be in the waking hours during the day, the lowest at night (e.g., the nocturnal dip). The amount of this natural blood pressure “dipping” varies by the person; some dip lower than others.

However, melatonin could aid this process. According to a randomized, double-blind, placebo-controlled trial, research suggests that daily nighttime melatonin (2.5 mg) could help reduce blood pressure in those with essential hypertension.

Volunteers — with untreated essential hypertension — were given 2.5 mg of melatonin daily for three weeks (one hour before sleep). They found a reduction in both systolic and diastolic blood pressure during sleep; 6 and 4 mm Hg, respectively.

So, the repeated bedtime dose of melatonin significantly reduced nocturnal blood pressure. Of course, further research is needed. Some believe it has to do with melatonin’s relaxing effects.

The Bottom Line

Melatonin is a naturally occurring sleep hormone; its use as a supplement to help support healthy sleep is proven. However, it may have positive effects on helping to reduce blood pressure as well.

Hypertension, or high blood pressure, affects millions. Most manage it with the use of medications — but there are natural ways to manage it, many of which require changes in lifestyle and diet.

Melatonin has been shown to help reduce nocturnal blood pressure in one research study, probably due to its calming effects. But, further research is needed to validate the extent of its impact.

Sources:

Melatonin: What You Need To Know | NCCIH

What Is Circadian Rhythm? | Sleep Foundation

Understanding Blood Pressure Readings | AHA

What is High Blood Pressure? | AHA

Facts About Hypertension | CDC

Daily Nighttime Melatonin Reduces Blood Pressure in Male Patients With Essential Hypertension | Hypertension | AHA Journals

Healthy Directions Staff Editor