Melatonin and sleep

May 2024

Image credit: Ketut Subiyanto on Pexels

As we move into travel season and people are going farther distances, we've had more questions about the sleep aid and hormone melatonin. Does it work for jet lag? How does it work? What are side effects? Should I use it? We thought we'd delve into the topic of melatonin for this month's blog.

What is melatonin? What does it do?

Isolated in 1958 by Aaron B. Lerner, a dermatology professor, and his team at Yale University, melatonin is a hormone produced by the pineal gland, which is a small pinecone shaped gland located behind the thalamus in our brains. The pineal gland is part of the endocrine system, which makes and releases hormones, chemicals that coordinate different functions in our bodies by travelling via the circulatory system and sending signals to our organs, skin, muscles, and other tissues.

Melatonin helps to regulate the sleep-wake cycle. Our bodies produce higher levels of melatonin at nightfall, when daylight diminishes, reaching maximum production at the early hours of the morning. The initial effects of the increased levels of the hormone are to make us drowsy, facilitating sleep.

What do our bodies use to produce melatonin?

Melatonin is produced in our bodies from tryptophan, an amino acid found in foods that we eat. Incidentally, tryptophan is also used by our bodies to produce other hormones (serotonin, which helps to regulate appetite, sleep, mood, and pain) and vitamins (niacin, or B3, used for energy metabolism and DNA production). Examples of foods containing tryptophan include:

cheese
chicken
egg whites
fish
milk
sunflower seeds
peanuts
pumpkin seeds
sesame seeds
soy beans

Image credit: Anna Schvet on Pexels

The amount of melatonin produced varies from person to person, and scientists have observed that more melatonin is produced when the pineal gland is bigger. We don't completely understand the impact of that, but we know that the amount of melatonin produced varies as a function of the size of the pineal gland.

Melatonin is known to have anti-inflammatory effects, as well as the ability to regulate sugar in our bodies. An excess of melatonin can lead to an intolerance of sugar and potentially lead to diabetes.

It has been observed that age has an impact on the amount of melatonin produced -- the older a person is, the less melatonin their body produces. This could be caused by factors such as the age of the pineal gland itself and a diminished capability, or the presence of cataracts. Cataracts prevent daylight from entering the eyes so the receptors in the retina which signal the body to produce melatonin aren't stimulated.

Certain medications can also reduce melatonin production, for example some sedatives used to promote sleep, some anti-inflammatory medications, and some beta blockers. Certain sedatives which require higher doses over time because of increases in tolerance may also deregulate our melatonin cycle.

On the flip side, melatonin can reduce the effectiveness of certain medications, in particular certain anti-depressants, and it can enhance the effect of others, for example, some diabetes medications.

Melatonin can also affect certain conditions negatively, for example, it can worsen certain rheumatic diseases.

Please feel free to consult with our pharmacists if you have any questions about melatonin and drug interactions or specific conditions, as each situation is unique.

Image credit: Ketut Subiyanto on Pexels

What does all this mean for using melatonin as a sleep aid?

Our bodies don't develop a tolerance for melatonin (building tolerance means needing to take more over time to have the same effect), nor do we get addicted to it, and our bodies don't go through withdrawal symptoms when we stop taking melatonin. Despite these positive points, we still need to be very careful about taking it.

In some individuals, for example, taking even a small dose can lead to higher-than-normal levels of melatonin in their body, potentially bringing on side effects such as headaches, nightmares, dizziness, sleepwalking, or nausea. Higher doses of melatonin could raise blood-sugar levels, especially for individuals who are already prone to diabetes.

Less common melatonin side effects may include:

short-lasting feelings of depression
mild tremor
mild anxiety
abdominal cramps
irritability
reduced alertness
confusion or disorientation

Scientific studies, including meta-analyses, show that melatonin can help individuals fall asleep faster, which could increase the total sleep time. The difference is not great, but it is statistically significant.

Its effectiveness depends on the dosage, when it's taken, on the person's age, and individual predispositions. There are some people who respond better to it than others.

Good bedtime habits are always recommended - take a look at one of our past blogs, on sleep:

Click here to go to our blog about sleep in a new window

Recommendations for taking melatonin as a sleep aid for adults and children include:

Take it on an empty stomach so that it can be better absorbed by the body.
Take it 30 to 120 minutes before going to bed. The ideal timeframe is likely around 60 to 90 minutes.

At this point, there is not enough information about the effect of melatonin use on fetuses, so it is not recommended for pregnant individuals.

Also keep in mind that melatonin is classified as a dietary supplement by the U.S. Food and Drug Administration (FDA), which means that it is regulated less strictly than a prescription or an over-the-counter drug would be. In certain other countries, for example the UK, it is considered a medication and can only be obtained with a prescription.

What's the bottom line?

If you would like to use melatonin as a sleep aid on a longer-term basis, discuss this with your doctor.

Having it available with you for jet lag could be a good strategy for getting on a new time zone more quickly. We would still recommend that you speak with a health professional about doing so, just to double check how it might affect your individual situation.

Our pharmacists are more than happy to review your or a loved one's situation -- just drop by.

References and resources