Evidence: Very High Possible Benefits: Very High Safety: High
TABLE OF CONTENTS
What is melatonin?
Melatonin is a hormone that the brain produces when the environment around a person gets dark. It is often taken as a supplement for improving sleep quality, for which it is the most useful supplement we know. This article is about the main benefits of melatonin, its potential side effects, the best time to take it, and more.
Possible benefits
All of the potential benefits mentioned below are dose-dependent. As with most other supplements, there is a sweet-spot dose that allows you to get most of the benefits without causing meaningful side effects or tolerance buildup in the body. We will discuss the best dosing protocol later in this article.
Major benefits
Improved sleep quality – When taken before bed, melatonin can make it easier to fall asleep and increase sleep quality and duration. This benefit applies to nearly everyone but it is most notable in people with insomnia.
Reduced jet lag – People going through jet lag or insomnia caused by switching time zones experience a great improvement in their sleep, energy levels, and well-being when they use melatonin to get used to the new time zone.
Reduced stomach ulcers – Melatonin is very protective against stomach ulceration induced by aspirin and h. pylori. This benefit likely applies to duodenal ulcers as well.
Minor benefits
Reduced cancer mortality – While more research is necessary, melatonin supplementation can greatly reduce cancer mortality in people with solid tumors (typically by about 25%).
Reduced tinnitus – Multiple human studies find reductions in ear ringing and other tinnitus symptoms.
Antioxidant effects – Melatonin can improve the antioxidant enzyme profile and be somewhat helpful in protecting the body from oxidative stress.
Increased growth hormone – The supplement can slightly increase growth hormone levels.
Reduced intraocular pressure – As little as 0.5 mg of melatonin can reduce intraocular pressure in adults.
Lowered liver enzymes – This benefit suggests melatonin may be slightly hepatoprotective.
Improved memory – An increase in memory retention under stressful periods was found in one human study. This benefit is most certainly related to an improvement in REM sleep.
Improved triglyceride levels – This benefit is small and unreliable but can apply to some people, especially those with high triglycerides.
Reduced symptoms of GERD – In one human study, 3 mg daily was able to significantly reduce heartburn and other symptoms of gastroesophageal reflux disease (GERD). Most of the improvements are secondary to melatonin increasing lower esophageal pressure.
Many unmentioned benefits related to improved sleep – The improvements in sleep quality can lead to a cascade effect and improve various other aspects of health, such as reduced migraines, faster muscle recovery, and improved emotional health. However, these benefits are secondary and may not occur if melatonin doesn’t increase one’s sleep quality much.
Possible side effects
The side effects below are dose-dependent. The risk for them increases (often linearly but sometimes exponentially) as you increase the dose. Some of the side effects only apply to very high doses.
Dysregulated sleep cycle – When taken at the wrong time (any time other than right before bed), melatonin can quickly dysregulate your sleep cycle.
Addiction – The supplement can be psychologically addictive. When you stop taking the supplement, you may experience mild symptoms of withdrawal but these are largely unexplored by science.
Sedation and sleepiness – Melatonin can make you less alert and more tired and sleepy, so it’s best to take it when you want to sleep or relax.
Allergic reaction – An allergy to this supplement is rare but possible.
Nausea – This side effect is most common when people take the supplement on an empty stomach.
Diarrhea – You can usually prevent diarrhea or stomach discomfort by taking this supplement with a meal.
Toxicity – While acute toxicity is extremely rare, taking high amounts of this hormone could lead to mild health problems over time. To prevent this from happening, staying below 5 mg in a day is best unless you have a great reason to take more.
Contamination – Contaminated supplements are uncommon in the USA and other well-regulated countries. However, if you wish to buy products from China, India, or other countries without strict regulations, beware that the supplements may be contaminated. Either way, you need to choose the brand you order from wisely. Always read through some reviews for the specific product before you buy it. The FDA (Food and Drug Administration) has the power to regulate dietary supplements but can only do so after they have been on the market for a while. That’s because supplement companies are not obligated to announce to the FDA when releasing a new product. The FDA has to discover the product and test it for potential impurities, which can take a lot of time. During that time, the supplement can be sold on the market even if it’s impure. Also, supplement companies can change their manufacturers without announcing it to the FDA.
Who should not take melatonin?
You should probably avoid taking melatonin if you:
already sleep well and produce enough melatonin endogenously
sleep in complete darkness and eliminate blue light at least 2-3 hours before bed (in which case, you should not need to take the supplement)
experience a severe adverse reaction after taking the supplement
are pregnant or breastfeeding (while it can be safe to take this supplement during pregnancy or breastfeeding, it can put some unnecessary risk to the child)
Who will benefit the most?
You should consider taking the supplement if you:
have difficulty falling asleep and staying asleep
are going through a jet lag
get exposed to blue light at night and are unable or unwilling to change that
have stomach ulcers
experience lots of stress and anxiety
have GERD (Gastroesophageal reflux disease)
have a high budget for supplements and are willing to experiment with a variety of them (assuming you don’t fall into any of the categories that should avoid this supplement, melatonin appears relatively safe and is unlikely to do more harm than good for most people)
How much melatonin should you take?
The sweet spot typically ranges between 0.5-3 mg daily for most people. This amount should provide most of the benefits without meaningful side effects.
The higher end of this range usually provides slightly more benefits in the short term. If you plan to take this hormone for a longer time (multiple months or years), the lower end is probably a better way to go since it is safer and you could theoretically develop tolerance to the supplement if you were to take higher doses.
The upper safety limit for this supplement is not well-established. To stay on the safe side, don’t take more than 5 mg daily unless you have a great reason to do so. Higher amounts may cause problems if you take the supplement for a prolonged period.
Like most other supplements, it is best to cycle melatonin and take about two days off weekly to prevent the buildup of tolerance in the long term.
Best time to take melatonin
The best time to take melatonin is right before you want to fall asleep. Do not take the supplement at any other time of the day unless you have a great reason to do so. Melatonin is water-soluble, so you don’t have to take it with food to absorb it well. Taking the supplement with food is better if it causes stomach upset when you take it on an empty stomach.
However, because it is often best to take this supplement before bed, it’s usually best to take it without food to prevent any problems associated with eating late.
If you take this supplement on an empty stomach, the short-term effects will kick in faster and be more pronounced.
Interactions
Resveratrol Resveratrol can increase the effects of melatonin.
Vitamin C These two supplements support each other’s antioxidant effects. Melatonin can also diminish some of the prooxidant effects of vitamin C.
Where to buy melatonin?
In most countries, Amazon is the best option for ordering melatonin supplements. They offer some very affordable products backed by many positive reviews. Also, you can choose from a wide range of brands without having to search through other markets on the Internet.
Some brands display the dosage per serving instead of per pill or capsule. Therefore, you may accidentally buy something less potent than you intended. Do not fall for this marketing trick.
FAQ
As with most other supplements, it is best to cycle melatonin and take a break from it for about two days per week to reset your tolerance back to baseline. That will keep your body sensitive to the supplement and allow you to keep getting the benefits in the long term.
All of these options are fine. The two most important things to consider are the price and dosing. Powders are almost always the cheapest form. However, you may need a highly accurate scale to dose them correctly (preferably 0.001g). You can get one for as little as $20 from Amazon. Dosing the powders also takes time which can add up over months or years. The disadvantage of capsules is that they are often made of bovine gelatine, which rarely comes from ethical sources.
Do not take this supplement in the morning unless you have a great reason to do so. Melatonin can make you feel sleepy and dysregulate your sleep cycle. The best time to take this supplement is before bed because it can improve sleep quality.
This supplement should not become harmful once it exceeds the expiration date. However, it can lose potency over time. Keep this supplement in a cold, dark, and dry place so it remains as potent for many months or even years.
While acute toxicity is rare, taking very high amounts of this supplement could lead to various problems over time. High doses can also make you develop tolerance much faster than lower doses.
While you could safely take higher doses, there is usually no point in taking more than 3 mg of this hormone daily. This amount should give you most of the benefits without meaningful side effects.
The half-life of this hormone in the body is about 20-40. The supplement stays in your system for about 3 hours hours after you consume it.
The benefits related to improved sleep quality will become notable right after you start taking the supplement. As for the long-term benefits such as the reduction in cancer mortality, you need to take the supplement for about 2-4 weeks to begin noticing most of them.
Most melatonin supplements on the market are vegan-friendly, but always check the label to make sure. If you buy the supplement in a capsulated form, beware that the capsules often contain animal-based gelatin. Instead, find a brand that puts its products into cellulose capsules.
No, it does not. The supplement should not interfere with fasting in any significant way.
References
Most of the information in this guide is based on scientific research that can be found and verified in the PubMed medical library. We highly encourage you to use the library to verify anything you read in this article. We excluded from consideration studies that are either confounded or have a high conflict of interest.
