Oral Rehydration Salts Thailand: Where to Buy and How to Use

If there is one thing worth keeping in your bag on Koh Lanta, it is a few sachets of oral rehydration salts. In Thailand they are sold almost everywhere, they cost very little, and they replace the salts you lose through sweat far better than plain water alone.

This guide covers where to buy them, how to mix and drink them properly, how they compare with sports drinks, and who should check with a pharmacist first. For the bigger picture on spotting the warning signs, see our guide to dehydration in Thailand.

What are oral rehydration salts?

ORS is a carefully balanced mix of glucose and salts, mainly sodium and potassium. The balance matters. A small amount of glucose helps your gut absorb sodium, and water follows the sodium into your body. That is why ORS rehydrates you more effectively than water when you have been sweating heavily, have had diarrhoea or vomiting, or have been out in the sun all day.

It is not a fancy product. It is a simple, well-established remedy that doctors and pharmacists recommend all over the world.

Where to buy oral rehydration salts in Thailand

You will not need to search hard. Look for these product types:

• ORS sachets or powder: sold in pharmacies, often near the counter. You mix one sachet with a set amount of water.
• Ready-to-drink electrolyte drinks: found in convenience store fridges. Check the label, because some are close to ORS and others are closer to sports drinks.
• Effervescent electrolyte tablets: handy for a beach bag, though the salt content varies between products.

Pharmacies are common in Saladan and along the main west-coast road, and pharmacists are used to tourists asking for rehydration salts. If you are not sure which product to pick, tell them what it is for, such as heat, an upset stomach or a child, and they can point you to a suitable one.

How to mix and drink ORS properly

The most important rule is simple: follow the packet. Different products are designed for different amounts of water, so do not guess.

1. Use safe water. Bottled water is the easiest choice on the island. Do not use tap water.
2. Measure the water. Use the exact volume the packet states. A standard small water bottle often makes this easy, but check the size.
3. Do not make it stronger. Adding an extra sachet or using less water makes the drink too salty, which can make dehydration worse rather than better.
4. Do not add sugar or juice. It upsets the balance that makes ORS work.
5. Sip slowly. Small, regular sips are easier on the stomach than gulping, especially if you feel sick.
6. Store it sensibly. Once mixed, keep it cool and follow the packet’s advice on how long it lasts, usually no more than a day.

Many people find ORS tastes a little salty. Chilling it helps, and flavoured versions are widely available.

Electrolyte drinks in Thailand: ORS vs sports drinks

Convenience store fridges are full of brightly coloured drinks promising electrolytes, and it is tempting to grab one instead. They are not the same thing.

• ORS: designed to rehydrate, with more sodium and a modest amount of glucose. Best after heavy sweating, an upset stomach or a hangover.
• Sports drinks: designed to fuel exercise, so they usually have much more sugar and less sodium. Fine as an occasional drink, but not a substitute when you are genuinely dehydrated.
• Coconut water: refreshing and contains potassium, but it is low in sodium. A nice extra, not a replacement.
• Plain water: perfect for everyday drinking, but on its own it does not replace the salts you lose in sweat.

Who should be careful with ORS?

ORS is safe for most people when used as directed, but a few groups should get advice first.

• People with kidney or heart conditions, or anyone told to limit salt or fluids.
• People on certain medicines, such as some blood pressure tablets or water tablets. Ask a pharmacist or doctor.
• Children: the amount depends on age and weight, so ask a pharmacist for a child’s dose and follow it. Babies and young children who are unwell can become dehydrated quickly and should see a doctor.
• People with diabetes: ORS contains some glucose, so check with a pharmacist which product suits you.

When ORS is not enough

Sometimes sipping simply is not working. If you keep bringing fluids back up or feel too sick to drink, a nurse-led drip is one option. Our Hydration Boost drip contains 1 litre of electrolyte fluids with vitamin B complex and magnesium, and is given at your accommodation after a health check, over roughly 45 to 60 minutes. Many guests find it helps them rehydrate when drinking feels impossible, but for most hot days, ORS and rest are all you need.

Your ORS checklist for Koh Lanta

Buy oral rehydration salts on your first day, mix them exactly as the packet says with bottled water, sip slowly, and use them on hot, active or unwell days. Choose ORS over sports drinks when you are genuinely dry, and ask a pharmacist if you have a health condition or are giving it to a child. If you feel too unwell to drink, message us on WhatsApp to ask whether a drip is suitable.

Frequently asked questions