Consumers

What is melatonin, and why can't it be sold as a supplement in Thailand?

8 min read · Updated 14 Nov 2026

What is melatonin? A hormone your body makes itself

Search “melatonin Thailand” and you will find a lot of confusion. Many people who sleep poorly, work night shifts or travel across time zones see colourful sleep gummies in online shops, read reviews from overseas, or are offered a bottle a friend brought back from a trip. The natural questions are: what is melatonin, is it safe, and can you buy it in Thailand as a dietary supplement?

The short answer: melatonin is a hormone your own body makes to help set the daily rhythm of sleeping and waking. In Thailand, however, melatonin is not permitted as an ingredient in food or dietary supplements. The Thai Food and Drug Administration (Thai FDA) has explained publicly that melatonin is a hormone and is not allowed in food. Melatonin products in Thailand exist only as registered medicines, dispensed with a doctor's prescription.

This article explains in plain language what melatonin is, how the body produces it, why gummies and capsules sold as supplements abroad are not foods the Thai FDA permits, what “natural melatonin” on a label really means, and how to check a sleep product before you buy. It is general information, not medical advice, and it does not recommend a dose of anything.

How the body makes melatonin, and why light matters

Deep in the brain sits a small gland called the pineal gland. It is the body's main source of melatonin. How much melatonin it releases depends on the light your eyes take in. As evening gets darker, the body releases more melatonin, a signal that rest is approaching. In the morning, when it is bright, melatonin levels fall and the body becomes alert for the day ahead.

This cycle is often called the body clock, or the sleep–wake rhythm, and it runs on a roughly 24-hour loop. Melatonin works more like a timing signal than a switch that makes you fall asleep on the spot. That is one reason travellers with jet lag and people working night shifts often feel their sleep is out of step: their internal clock has not yet caught up with the real time of day.

Everyday habits affect this rhythm, for example bright light late in the evening, phone or tablet screens close to bedtime, and going to bed and waking at different times each day. Understanding that melatonin is a hormone the body regulates carefully also helps explain why Thailand's public health authorities do not treat it as a food ingredient that anyone can buy and take on their own.

Melatonin supplements: why Thailand does not permit melatonin in food

“Melatonin supplement” is a popular search because in some countries, such as the United States, melatonin is sold as an ordinary dietary supplement, as tablets, capsules, gummies and liquids. It is easy to assume Thailand works the same way. It does not. Each country sets its own rules, and something sold as a supplement in one market may not be a food at all in another.

In Thailand, dietary supplements are governed by Ministry of Public Health Notification No. 293 B.E. 2548 (2005) on food supplements, and the Thai FDA keeps an advisory list of key ingredients that may be used in supplements. Melatonin is not among them. Senior Thai FDA officials have stated in the media that melatonin is a hormone and is not permitted as an ingredient in food, and the Thai FDA has found melatonin in sleep gummies on the market and issued warnings to consumers.

What this means in practice: any product sold as a food or supplement that contains melatonin is not a food the Thai FDA permits, whether it is made locally or imported. Fruit gummies, herbal teas, drinks or “sleep chocolate” – if melatonin is in the ingredient list, it is not permitted in food, regardless of the format or the amount.

For consumers this is a useful signal. If a product calls itself a supplement but its label or advertising says it contains melatonin, it is outside the food system the Thai FDA oversees. You cannot be sure how much melatonin is in each piece, where it was made, or what quality checks it passed.

Melatonin as a medicine in Thailand: prescription only

Melatonin medicines do exist in Thailand, but they are medicines, not foods. The only melatonin products that can be sold in Thailand are those registered as medicines under the Drug Act B.E. 2510 (1967), dispensed with a doctor's prescription. The difference matters. The medicine system assesses quality, safety and indications before approval, and doctors and pharmacists decide who should use a medicine, at what dose and for how long.

Because melatonin sits in the medicine system in Thailand, choosing a dose and deciding whether it suits you are matters for a doctor, not something to pick from the label of a foreign product. Numbers such as 3 milligrams, 5 milligrams or 10 milligrams printed on overseas bottles do not tell you which amount, if any, is right for you. People differ in age, health conditions and the medicines they already take.

If sleep problems are affecting your daily life, the sensible step is to see a doctor to find the cause. A doctor may suggest non-drug approaches first, or consider a medicine suited to you, which may or may not be melatonin. This article does not claim that melatonin resolves insomnia; that has to be assessed person by person.

Sleep gummies from abroad and online shops: what to check before you order

Consumers most often meet melatonin products through online shops, marketplaces, personal shopping services and social media reviews. These products are often brightly coloured, fruit-flavoured gummies that look like sweets, with English-only labels and words such as “supplement” or “sleep aid”, so they look no different from everyday vitamins.

Keep in mind that a foreign label follows the rules of its own country. The word “supplement” on a bottle does not make it a dietary supplement permitted in Thailand. A product sold in Thailand as a food must carry a 13-digit food serial number inside the Thai FDA logo frame and a Thai-language label. If melatonin appears in the ingredient list, the product is not a food the Thai FDA permits even if a number is printed on it, because genuinely permitted foods do not contain melatonin.

Some sellers avoid the word melatonin in the product name and list it only in small print on the back, or once in English. Ask for a clear photo of the back label before ordering. Also be careful with gummies that look like sweets: in a home with young children, they are easy for a child to find and eat.

The diagram below sums up the warning signs and the actions you can take when you see a sleep product online.

What does "natural melatonin" mean?

The phrase “natural melatonin” comes from a real scientific observation: some plants and foods, including certain fruits, nuts and grains, naturally contain small amounts of melatonin. Eating these foods as part of a normal diet is simply eating food. It has nothing to do with adding melatonin to a product.

On a label or in an advert, though, the phrase means something different. A product that says “natural melatonin”, “plant-based melatonin” or “naturally extracted” is still a melatonin product. The source does not change the status of the substance. Melatonin extracted from plants and melatonin made in a laboratory are the same molecule, and neither may be used as a food ingredient in Thailand.

Notice too that “natural” is often used to make a product feel gentler and safer. Safety depends on the amount, the person using it and the quality of manufacture, not on whether the substance came from a plant. When you see this wording, read the actual ingredient list and check the number on the label before deciding.

Check a sleep product before you buy, step by step

Before buying any sleep product, whether from a pharmacy, a convenience store or an online shop, these few minutes of checking are worth it.

1. Read the ingredient list. Look for melatonin in Thai or English. If it is there, the product is not a food the Thai FDA permits.
2. Find the number on the label. A dietary supplement must show a 13-digit food serial number inside the Thai FDA logo frame. See how to read a supplement's 13-digit number.
3. Look the number up. Enter it in the Thai FDA number checker on this site, which draws on the Thai FDA's public product search.
4. Compare the result with the product in your hand. The product name, the manufacturer or importer and the product type should match the label. If the number belongs to another product, or is not found, do not buy it.
5. Read the claims. A dietary supplement must not claim to cure a disease. Wording that suggests it is a remedy for insomnia or replaces sleeping pills is a warning sign.

For a fuller guide to checking each type of number, read how to check a Thai FDA number. If you find a suspicious product, for example one sold as a supplement that contains melatonin, photograph every side of the label and the online shop page, and report it to the Thai FDA hotline 1556.

Looking for sleep support? Ingredients Thailand permits in supplements

Leaving melatonin out does not mean there are no relaxation-type supplements. Several ingredients are on the Thai FDA advisory list and may be used in dietary supplements within set daily limits. Common examples:

• L-theanine, an amino acid found in tea leaves: up to 200 milligrams per day.
• Gamma-aminobutyric acid (GABA): up to 250 milligrams per day, for the raw material described in the list.
• Chamomile: dried flower powder up to 100 milligrams per day, and German chamomile water extract up to 108 milligrams per day.

These figures are the ceilings manufacturers design formulas around, not amounts consumers should aim for. Follow the directions on the label of a product with a valid food serial number, and remember that a dietary supplement is not a medicine and cannot prevent or cure disease. For each ingredient, its conditions and the ingredients that are not permitted, see Sleep supplement ingredients in Thailand: what is permitted and what is not.

Habits matter as much as products: going to bed and waking at about the same time every day, dimming bright lights and screens before bed, avoiding caffeine from the afternoon onwards, and keeping the bedroom dark and quiet. None of this requires buying anything.

When to talk to a pharmacist or doctor

Some people should speak to a pharmacist or doctor before using any sleep-related product, whether a medicine or a dietary supplement:

• people who are pregnant or breastfeeding
• people who take other medicines regularly or have a long-term health condition
• children and teenagers, who should not be given sleep products without a doctor's advice
• older adults, who often take several medicines at once
• anyone who drives or operates machinery around the time they would use the product

Also see a doctor if you have had trouble sleeping for several weeks, wake so often at night that it affects your work, or have other symptoms such as loud snoring with sudden waking, unusual daytime sleepiness, or marked mood changes. Trying products on your own can mean the real cause goes unnoticed.

In short: melatonin is a hormone the body makes to set the timing of sleep and waking. In Thailand it is not permitted in food or dietary supplements and is available only as a registered prescription medicine. Before buying a sleep product, read the ingredients, check the Thai FDA number, and choose products made with ingredients that are permitted in supplements.

Sources

1. Ministry of Public Health Notification No. 293 B.E. 2548 (2005) on food supplements · Open source · Search our archive
2. Thai FDA announcement on guidance for the use of key ingredients in food supplements (dated 8 July 2024) · Open source · Search our archive
3. Drug Act B.E. 2510 (1967) · Open source · Search our archive
4. Thai FDA announcement on food advertising criteria B.E. 2569 (2026) · Open source · Search our archive

This article is for general information. It is not a Thai FDA ruling or legal advice, and rules change — check the latest notification or ask an expert before filing or producing.

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