Melatonin vs L-Theanine for Sleep

Melatonin has been a hot topic when it comes to sleep aids for the past decade and a half. As a supplement, it’s become the face of the safe and sustainable sleep aid campaign. There are melatonin supplements in the form of powders to mix into beverages, capsules or pills for easier consumption, and even gummy varieties meant to be palatable for young adults and children.

Melatonin is everywhere. Therefore, it seems like it would be a no-brainer to have it as a key ingredient in any natural sleep aid. So why did we exclude this key ingredient from our UEN Sleep Support? Additionally, why did we shift focus to ingredients like L-Theanine? Let’s find out below.


Melatonin is a hormone that the body naturally produces in the pineal gland, just about the center of your brain. It signals the body that it is time to wind down and initiates the process of sleeping. At the end of the sleep cycle, it signals your body to wake up. There are several factors that affect the natural production of melatonin in your body. Some of these include the amount of sunlight (or orange/blue light in your surroundings) and your own internal body clock, known as your circadian rhythm. 


One of the most common uses of supplemental melatonin is from people who need to fight their own circadian rhythm, or to persuade their bodies that it is time to sleep. This can be due to several reasons. It can include disruptions in dark/light cycles throughout the day, late-day caffeination, or underlying sleep issues. 

Reasons to Avoid Melatonin

Although melatonin is touted as a safe supplement for sleep aid, it does have side effects. Taking melatonin too late in the day or in too high a dose can result in feeling particularly groggy or having brain fog upon waking. Many supplements include supraphysiological (larger or more potent than would occur naturally) doses anywhere from 2-5 mg which is simply way too much and can cause dependency.

Sometimes melatonin can assist in falling asleep but won’t keep you asleep or give you higher quality sleep. There is also evidence of dependency growing over time with people taking supplemental melatonin. Basically, the longer you take melatonin, the more you become dependent on it to fall asleep. When you try to come off, it becomes difficult to fall asleep without it. Melatonin also has a list of possible unwanted side effects when taken in conjunction with certain medications, necessitating a proper check of cross-reactions. 


L-Theanine is a nonessential amino acid, naturally found in a variety of teas. L-Theanine has been shown to have anxiolytic (anti-anxiety) properties, particularly in acute stress, and facilitates sleep. Studies have shown that L-Theanine can reduce or inhibit the excitatory effects of caffeine, so it can be especially beneficial for people who drink coffee, energy drinks, or pre-workout. 


Additionally, L-Theanine has been shown to help decrease sleep latency and improve NREM, or non-rapid eye movement, sleep. Through this pathway, L-Theanine increases the quality and duration of sleep. With these qualities, combined with other synergistic ingredients, we found that you don’t always need the sometimes overbearingly strong side effects of melatonin to improve your sleep.

In a 2015 study, the researchers concluded that "L-Theanine promotes relaxation without drowsiness. Unlike conventional sleep inducers, L-theanine is not a sedative but promotes good quality of sleep through anxiolysis. This review suggests that L-theanine is a safe natural sleep aid."



Of course, you don’t want to rely solely on a supplement or supplements to be able to sleep better. In fact, supplements like L-Theanine are only part of the equation. A great sleep routine is your foundation. Supplementation is what can then help you optimize and take your performance to the next level. 

It is important to have a good sleep routine that includes: 

  • Bedroom temperature of 64-68 degrees F
  • Dark room (block out small lights)
  • Ambient noise if needed
  • No water before bed (this has more to do with being able to have sustained uninterrupted sleep. Frequently drinking fluids before bed causes people to wake up in the middle of the night)
  • Limit bedroom activities (don’t watch TV in it, don’t play on your phone)
  • Have a bedtime routine
  • Have a regular bedtime
  • No video games or high CNS stimulating events before bed
  • And the icing on the cake, proper supplementation including L-Theanine, such as UEN Sleep Support 

Melatonin vs L-Theanine for Sleep

While melatonin is a commonly used supplement for sleep, it does have some short- and long-term side effects. For these reasons, we decided not to include melatonin in UEN Sleep Support. Instead, we developed a synergistic blend of ingredients that work together to help improve your sleep quality.

L-Theanine is an incredibly beneficial amino acid for helping regulate processes that reduce stress and increase relaxation. L-Theanine also has been shown to improve NREM sleep, which is a vital component of restful and refreshing sleep. We recommend approximately 200 mg of L-Theanine, which is the dosage we use in UEN Sleep Support. We also have included 480mg of CherryPURE® Tart Cherry Extract, which helps increase natural melatonin levels in the body and enhance sleep.

All in all, sleep is one of the most easily adjustable performance enhancers you can optimize in your life. A lack of sleep has been linked to increased reaction time, increased injury risk, and generally poorer performance in both physical and mental tasks. It’s no secret that the better you sleep, the better you will recover, and the better you will perform in whatever you do, whether it’s physical or mental. Getting enough sleep and quality sleep is a huge key to achieving all your long-term goals. Luckily, there are many actions you can take to improve your sleep as listed above, which culminate with taking a supplement that includes L-Theanine, such as UEN Sleep Support. As part of a well-rounded sleep routine, it can help you sleep better, recover faster, and perform better.*


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Lyon MR, Kapoor MP, Juneja LR. The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial. Altern Med Rev. 2011 Dec;16(4):348-54. PMID: 22214254.

Kakuda T. Neuroprotective effects of theanine and its preventive effects on cognitive dysfunction. Pharmacol Res. 2011 Aug;64(2):162-8. doi: 10.1016/j.phrs.2011.03.010. Epub 2011 Apr 6. PMID: 21477654.

Kim S, Jo K, Hong KB, Han SH, Suh HJ. GABA and l-theanine mixture decreases sleep latency and improves NREM sleep. Pharm Biol. 2019;57(1):65-73. doi:10.1080/13880209.2018.1557698