Glycine vs Melatonin: An Honest Comparison For Sleep, Side Effects & More!

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Last Updated on December 12, 2022 by theworldofsleepstaff

Glycine and melatonin are two popular supplements used to improve sleep quality. Both have been studied extensively, with research showing that they may be effective in helping people fall asleep faster and stay asleep longer.

However, while each has its unique benefits, there are some important differences and similarities that must be considered when deciding which supplement to take.

For example melatonin tends to be better at improving sleep quality, deep sleep, and helping with jet lag. Whilst glycine may help reduce stress and promote relaxation, which in turn can make it easier to get to sleep.

But that’s just scratching the surface when it comes to the similarities and differences between glycine and melatonin and the science behind them. Luckily we delve into all of that and more right here.

Note: This content was only written as a reference, using third-party background information. It is not medical advice; As always, it is essential to do your research and speak with a healthcare provider if you have questions or before taking any new supplement.


  1. Which Is Better For Sleep?
  2. The Similarities
  3. The Differences
  4. Can I Take Glycine And Melatonin Together?
  5. How Do The Side Effects Compare
  6. Top Tips When Taking Melatonin For Sleep
  7. Top Tips When Taking Glycine For Sleep
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Glycine vs Melatonin: which one is better for sleep?

Both glycine and melatonin are naturally occurring compounds found in the body, but they have very different effects on sleep.

Glycine is an amino acid that occurs naturally in the body and can be found in certain foods like pork, beef, turkey, fish, dairy products, soybeans and legumes.

It plays a role in various physiological processes related to sleep, including helping to regulate the hormone cortisol and promoting relaxation. Therefore, glycine has been studied for its potential to improve sleep quality and reduce daytime fatigue.

Fundamentally Glycine is an amino acid that acts as a neurotransmitter in the brain, helping to regulate mood and stress levels.

Glycine also helps to stimulate the natural production of GABA (gamma-aminobutyric acid), a neurotransmitter that has a calming effect on the body. It is a supplement that helps reduce stress and improve sleep quality.

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Melatonin is a hormone produced in the brain’s pineal gland, which regulates our internal clock and helps us fall asleep. It also helps to regulate circadian rhythms, helping to ensure that our bodies and minds are in sync with the natural day-night cycle.

As a supplement, melatonin can help to reset our body clock and adjust to changes in time zones or jet lag.

So which one is better for sleep?

Well both glycine and melatonin have been proven to be effective at helping people fall asleep faster. Still, research has found that melatonin promotes deep and restorative sleep more effectively. On the other hand, glycine can help to reduce stress levels and make sleeping easier to come by, but it won’t necessarily provide the same deep sleep as melatonin.

Ultimately, it’s up to you to decide which works best for you. Melatonin might be better if you seek more profound, more restorative sleep. However, if you’re looking for a way to wind down and get better quality sleep, then glycine may be your best bet.

No matter which one you choose, take it as directed by your doctor or pharmacist and only use it as needed.

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Glycine vs Melatonin: The Similarities

Glycine and melatonin are both natural, safe compounds that can help improve sleep quality. Apart from that, they have a few other similarities as we show you next:

1. Glycine & Melatonin Are Both Naturally Occurring Substances

These two compounds can be found naturally in certain foods and some of the body’s tissues. In addition, glycine is found in many types of animal protein, while the pineal gland produces melatonin in the brain.

2. They Both Improve Sleep Quality

Glycine and melatonin have been shown to help people fall asleep faster, stay asleep longer and experience an overall better night’s sleep.

In addition, studies have found that both supplements can help reduce the time it takes to fall asleep and improve overall sleep quality and duration.

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3. They Both Work By Calming The Nervous System

Glycine regulates neurotransmitters in the brain, while melatonin regulates the body’s internal clock.

They both work to calm and relax the nervous system, making it easier for people to fall asleep and stay asleep longer.

4. They Both Have Few Or No Side Effects

Although glycine and melatonin are natural supplements, they can still cause minor side effects such as headaches, nausea, dizziness or irritability.

However, these are generally mild and short-term and should diminish over time with continued use, but this needs a doctor’s opinion.

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Glycine vs Melatonin: The Differences

Although both glycine and melatonin offer similar benefits in improving sleep, there are a few key differences between them.

1. Glycine Can Help Reduce Stress & Anxiety Levels

Studies have found that taking glycine supplements can help to reduce stress levels, improve mood, and even reduce symptoms of depression and anxiety. On the other hand, melatonin is not thought to affect stress or mood levels.

2. Melatonin May Help Reduce Jet Lag

Melatonin helps reduce the symptoms of jet lag, while glycine has not been studied for this purpose.

3. Melatonin Is More Effective For Deep Sleep

Although both supplements can help people fall asleep faster and stay asleep longer, melatonin promotes deep, restorative sleep more effectively. Studies have also found that taking melatonin before bedtime can improve sleep quality.

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Can I Take Glycine And Melatonin Together?

The use of glycine and melatonin together may help improve your sleep quality.

Glycine is an amino acid found naturally in the body, while melatonin is a hormone that helps regulate sleep cycles. Both supplements have been used individually to treat insomnia and other sleep problems. Taking them together could magnify both effects, although there needs to be more research on the combination and you must talk to your doctor first due to potential side effects.

It’s important to note that taking glycine and melatonin together may have potential side effects and interactions with other medications you are taking, so it’s best to speak with your doctor before combining them. Your doctor can also help you decide if this supplement combination is right for you and give advice on the best dosage.

When taken together, glycine and melatonin could work in different ways to help improve sleep quality. Glycine can bind to GABA receptors in the brain, which helps reduce stress and anxiety levels while promoting relaxation. Melatonin helps stimulate sleep onset, making it more effective closer to bedtime.

Taking glycine and melatonin together could be beneficial if you want to improve your sleep quality. However, you must speak with a doctor before combining these supplements, so they can help determine whether it’s the right choice for you.

Additionally, make sure to follow all dosage instructions when taking any supplement. Doing so may help you get the most out of your sleep routine.

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Glycine vs Melatonin: How Do The Side Effects Compare


The known potential side effects of taking glycine are:

1. Headache

Some say that they have experienced a mild headaches after taking glycine.

2. Lightheadedness

Lightheadedness may occur in some people; if this happens, it is best to discontinue the supplement.

3. Nausea

Some people may experience nausea when taking glycine for sleep aid. It is essential to talk to a doctor if this side effect is experienced.


The known potential side effects are

1. Headache

Some people report experiencing mild headaches when they take melatonin for sleep aid. If this occurs, discontinuing the supplement and speaking to a doctor is best.

2. Daytime Sleepiness

Because melatonin is a hormone that helps the body sleep, some people report feeling drowsy during the day when they take it for sleep aid. This usually occurs if too much melatonin is taken late in the afternoon or evening.

3. Nausea

Some people may experience nausea when taking melatonin. It is essential to talk to a doctor if this side effect is experienced. If it persists, discontinuing the use of the supplement may be necessary.

Important Note On Side Effects

It is important to remember that everyone reacts differently to supplements like glycine and melatonin. Hence, it is essential to speak with a doctor before taking either.

They can help determine the best dosage for your individual needs. Additionally, it is essential to keep track of any side effects when taking these supplements and alert a doctor if anything seems off or unusual. Doing this is critical.

Finally, remember that these supplements are meant to supplement sleeping each night properly. Therefore, they should only be taken when necessary and with the advice of a doctor, so be sure to ask your doctor before starting any supplement for sleep aid.

Suppose you decide to use either glycine or melatonin for sleep. In that case, it is essential to take the recommended dosage, not exceed it, and always pay attention to any side effects you experience. Doing so can help ensure you get the most out of your sleep supplement and experience fewer complications. Good luck!

It is also important to note that there are specific people who should avoid taking either glycine or melatonin for sleep. These include (but are not limited to) pregnant and breast-feeding women, those with existing health conditions like hypertension or diabetes, and people under 18.

Please speak to your doctor before taking either supplement if you fall into these categories. Always remember to be safe when using any supplement.

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Top Tips When Taking Melatonin For Sleep

1. Settle Into A Routine: Aim to take melatonin supplements simultaneously each night to get the most out of taking them. This helps your body adjust its internal clock and become more effective at using melatonin to aid sleep.

2. Start With Small Doses: It’s best to take smaller dosages of melatonin to assess its effects. Start small and track the results, then incrementally increase the dosage if needed but ask your doctor for guidance.

3. Don’t Take It On An Empty Stomach: Melatonin is best taken one hour before bedtime but should be taken with a light snack for optimal absorption into your body.

4. Stick To The Recommended Dosage: Make sure you’re taking the exact dosage your doctor or a healthcare professional has instructed, as too much melatonin can lead to undesired side effects.

5. Try Other Natural Sleep Aids: Although melatonin is an effective supplement for improving sleep quality, several other natural remedies have been known to aid in achieving a healthy sleep routine, such as essential oils, Epsom salt baths and yoga. Try these out in conjunction with melatonin if you still have trouble sleeping.

6. Understand The Differences Between Melatonin And Glycine: Melatonin regulates your body’s natural sleep-wake cycle, while glycine is thought to help you stay asleep. Understanding the differences between these two supplements can help you decide which one is best for your needs

7. Monitor Your Sleep: To get the most out of taking melatonin or glycine, keep track of how well it improves your sleep quality. Please write down the time you take it and how long it takes for you to fall asleep. This can help you adjust dosages if needed and work with your doctor to find the best solution for your sleep troubles

8. Be Patient: Although melatonin or glycine may help improve your sleep quality, it’s essential to remain patient and remember that these supplements take time to work. It may take several weeks, or even months, for your body to adjust to the new sleep routine before you start experiencing the benefits.

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Top Tips When Taking Glycine For Sleep

1. Start Slowly: When taking glycine for sleep, it’s essential to start with a low dosage and adjust accordingly. Starting with too high of a dosage can lead to restlessness or uncomfortable side effects

2. Take With Meals: To ensure that the body absorbs enough glycine, it’s best to take it with meals. This helps ensure that the body is breaking down glycine for energy and thus able to reap its benefits.

3. Don’t Overdose: As with any supplement, it’s important not to overdose on glycine when taking it for sleep. Too much can lead to restlessness and other side effects, so following the recommended dosage instructions is essential.

5. Talk To Your Doctor: Finally, if you’re considering taking glycine or any other supplement for sleep, it’s always a good idea to check in with your doctor first. They can help you assess the best dosage and determine if there are any potential interactions with medications or supplements you already take.

Following these tips, you can get the most out of taking glycine. Doing so can give you better quality rest and wake you up feeling refreshed!

If you’re having trouble sleeping, speak with your doctor about trying melatonin or glycine as a supplement. Keep in mind these top tips when taking the supplements, and you’ll be well on your way to a good night’s sleep.