How Long Does It Take Melatonin to Work?

Melatonin is a hormone that we all naturally produce in the pineal gland¹. One of the pineal gland’s jobs is to determine whether it is light or dark outside; if it is dark, this small, pea-sized gland begins producing melatonin, which helps facilitate sleepiness.¹ 

Sometimes, though, people may struggle to feel sleepy at night. This is where melatonin supplements can come in. These supplements, often in pill, liquid, or gummy form, help to increase the levels of melatonin in our system so we can hopefully feel more sleepy at bedtime. 

There is a lot of conflicting information out there about how long melatonin takes to work. So in this article, we aim to clear up some confusion. We’ll go over how melatonin supplements work, how long they’ll take to work, the different types of melatonin supplements, their possible side effects, and more. 

Remember, it’s always a good idea to consult your doctor before introducing any new supplements.

How Does Melatonin Help You Sleep?

Melatonin is not a tranquilizer or sleeping pill, in that it doesn’t necessarily make you fall asleep or keep you asleep throughout the night. Instead, melatonin can help put your body into a state of relaxed sleepiness by adding to your body’s natural supply of the hormone².

Research shows³ that melatonin supplements can help people fall asleep slightly faster, improve their sleep quality, and increase their overall sleep time. Additionally, melatonin supplements have been found to help⁴ those with jet lag, as well as shift-workers, who need to stay up all night and sleep during the day. 

It’s important to note, though, that lights – especially blue lights emitted from screens like smartphones and laptops – impede the production of melatonin.¹ So even if you take a melatonin supplement, it won’t help you fall asleep if you have all the lights on and are staring at your phone until bedtime.
Instead, experts advise⁵ you to dim the lights in your home and avoid looking at screens two hours before bedtime to help maximize your melatonin production.

How Quickly Does Melatonin Make You Fall Asleep?

Most melatonin that you’ll buy for at-home use is taken orally – meaning it is either a tablet, capsule, liquid, or gummy that you’ll ingest. This means that it will pass through the digestive system⁶ before you’ll feel its effects. Since this is the most common way people are taking melatonin, we’ll use this to discuss melatonin’s effects. 

Melatonin levels will peak in the body about 60 minutes⁷ after ingestion, and you should start to feel sleepy one to two hours after taking the supplement.² Importantly, this will depend on the type of melatonin you’re taking. 

After taking melatonin, it should stay in your system anywhere between four and eight hours (depending on the dose and type of melatonin, as well as your unique metabolism). After that, your body’s melatonin level will return to the normal baseline value.⁷

When Should You Take Melatonin?

Most experts agree you should take melatonin supplements between one and two hours before your desired bedtime.² This will help support your body’s natural circadian rhythm, where melatonin levels naturally increase about two hours before sleep.⁵ 

To make sure you’re not negating the effects of melatonin, be sure to dim the lights around this time and avoid looking at tech devices like your smartphone or tablet.

Types of Melatonin 

Fast-Release Pills

When you find a melatonin supplement that simply says the dosage on it, it is likely a fast- or immediate-release supplement. These sorts of supplements release more quickly into the bloodstream, beginning to release about 20 to 40 minutes after swallowing them, and peaking after about one hour.¹   

Fast-release pills will likely only help you fall asleep, but there is little evidence to show that they’ll prevent you from waking up during the night. 

Extended-Release Pills 

Extended-release tablets⁸ are designed to release the active ingredient (in this case, melatonin) into the system gradually, rather than all at once. This ensures a prolonged therapeutic effect. 

Though studies are limited, experts believe extended-release melatonin supplements may help you not only fall asleep but stay asleep⁹ as well. 

Compared to immediate-release melatonin, these pills take a longer time to reach peak concentration and leave the body¹⁰. While some have posited that extended-release melatonin will cause morning grogginess, research shows no additional negative side effects with extended-release melatonin, and in fact, some research shows an increase in morning alertness.^{9, 10} 

Gummies

Melatonin gummies have the benefit of being chewable and sweet-tasting, which can be a plus if you’re giving your child melatonin or you don’t swallow pills well. Since these do seem an awful lot like candy, you must keep melatonin gummies out of reach of children, who might accidentally eat too many and experience negative side effects. 

Just like pills, gummies will have to pass through the digestive system and liver, so they should take effect¹¹ in roughly the same amount of time. 

The downside to gummies is that they often contain added sugars or sweeteners, which may be an issue for those avoiding sugar before bedtime. They also have a shorter shelf-life¹² compared to pills, which means their potency will diminish over time.

Patches

Melatonin patches are adhesive patches¹³ that deliver the melatonin directly through the skin. The benefit of these sorts of transdermal patches¹⁴ is that they sidestep the digestive system, so more of the melatonin is absorbed. Patches seem to release the melatonin more slowly through the night¹⁵, which may be beneficial for those struggling to stay asleep.

You should apply the melatonin patch to an area of the body with limited hair about one hour before your desired bedtime.¹³ 

Melts

Melts (or “quick-dissolve tablets”) are specifically designed to melt in the mouth – usually under the tongue or between the gums and the cheek. Many melatonin melt products are described as fast-acting.

Research experts say that this type of delivery method has its advantages, most notably “rapid onset of action¹⁶”, which means a shorter wait time for the effects to take place.

Liquid Melatonin 

Melatonin is available in liquid form as well. You might consider liquid melatonin since it can be easier to swallow than a pill. It can also be more child-friendly and likely absorbs slightly faster¹⁷ than a tablet (though only marginally faster than a capsule.) 

However, liquid melatonin will probably contain sweeteners, so if you’re avoiding sugar, you may want another option. 

Nasal Sprays

Melatonin is also available as a nasal spray. This may be beneficial to those who have trouble swallowing pills or want to avoid sugar. Plus, melatonin nasal sprays completely avoid the digestive system. Research shows that melatonin nasal sprays take effect faster than any other form of melatonin and have the highest bioavailability.¹⁵ This means more of the melatonin is actually getting into your system at a faster rate. 

Check out our guide: Best Melatonin Supplements for Sleep

Side Effects of Melatonin

According to the National Health Service (NHS), most people will not experience side effects¹⁸ when taking the appropriate dosage of melatonin. However, if you take too much or are sensitive to melatonin, the NHS says the most common side effects include: 

• Daytime fatigue
• Headache
• Dizziness
• Upset stomach
• Dry mouth
• Dry or itchy skin
• Pains in arms or legs
• Irritability or restlessness
• Vivid dreams or nightmares

The NHS reports that about 1 in 1,000 people may experience more serious side effects. These include: 

• Changes in eyesight/blurred vision
• Dizziness or confusion
• Feeling faint or passing out
• Increased depression
• Bleeding that doesn’t stop or unexplained bruising

In even rarer circumstances, you could have a severe allergic reaction to melatonin. You should call 911 immediately if you or somebody else experiences any of these symptoms after taking melatonin.¹⁸

• Swollen lips, mouth, or tongue
• Breathing difficulties
• Sudden dizziness, confusion, or drowsiness
• Inability to swallow
• Someone faints and can’t be woken
• Rash that is raised, swollen, itching, blistering, or peeling
• A child is limp or floppy / not responding

Does Melatonin Affect Other Drugs?

You should be cautious when taking melatonin with any of the following drugs¹⁹, as they may affect each other. 

• Antidepressants
• Blood pressure medications
• Benzodiazepines
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Opiates
• Oestrogens/Estrogens (contained in hormonal birth control and HRT)
• Psoralens (a psoriasis medication)
• Carbamazepine (for epilepsy)
• Quinolones or Rifampicin (specific types of antibiotics)
• Cimetidine (for stomach ulcers)
• Thioridazine (a schizophrenia medication)
• Zaleplon, zolpidem, or zopiclone (an insomnia medication)
• Warfarin (a medicine to prevent blood clots)

If you’re taking any of these medications, speak to your doctor before adding in melatonin. 

Natalie Grigson

Writer

About Author

Natalie is a content writer for Sleep Advisor with a deep passion for all things health and a fascination with the mysterious activity that is sleep. Outside of writing about sleep, she is a bestselling author, improviser, and creative writing teacher based out of Austin.

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