Motion sickness in Thailand mostly strikes on speedboats, in minivans on mountain roads and on ferries in monsoon swell. Thai pharmacies sell motion-sickness tablets, which work best taken before the trip, but where you sit, what you look at and which boat you choose matter just as much.
Almost anyone can get motion sickness if the movement is strong enough, says the US Centers for Disease Control and Prevention (CDC). Thailand offers plenty of it: a fast boat slamming over waves to the islands, a minivan swinging through hundreds of bends to Pai, a ferry rolling in the rainy-season swell. This page explains what helps, what the pharmacy can offer and who should be careful with the tablets. It is general information, not medical advice; ask a pharmacist or a doctor about your own case.
Motion sickness: the short version
- Usual symptoms
- Dizziness, nausea, vomiting, headache, cold sweat, going pale (NHS)
- Most susceptible
- Children aged about 7-12; women somewhat more than men; people with migraine (CDC)
- Best seat
- Front of a car or van; middle of a boat, away from the bow
- Medicine
- Works best taken before travel; ask a pharmacist which suits you
- Does not work
- "Non-drowsy" hay-fever antihistamines (CDC)
Why it happens, and who gets it worst
Motion sickness is a conflict of signals. Your inner ear feels the movement while your eyes, fixed on a phone or the inside of a cabin, tell the brain you are sitting still, and the brain reacts with nausea. That is why looking out at the horizon helps and reading makes it worse.
According to the CDC, children under two rarely get it, susceptibility peaks between about 7 and 12 years and then declines, and women are somewhat more prone than men. People with migraine or inner-ear problems are more at risk. Lack of sleep makes it worse, which matters after a late night before an early boat. The CDC also says the body gets used to motion over time, so the second and third boat trip of a holiday are often easier than the first.
What to ask for at a Thai pharmacy
Pharmacies across Thailand sell tablets against travel sickness. Our guide to medicines at Thai pharmacies explains how pharmacies and pharmacists work; this section covers what to ask for.
The CDC describes two main kinds of motion-sickness medicine. One is the older, sedating antihistamines, such as dimenhydrinate, meclizine or cyclizine. The other is scopolamine, usually given as a skin patch behind the ear. We could not confirm on an official Thai page which of these are sold over the counter in Thailand, or whether scopolamine patches are available, so tell the pharmacist what kind of trip you are making and let them suggest a product. Bring the name of anything that has worked for you at home.
Two rules from the CDC are worth knowing before you buy:
- Take it before you travel. The medicines work much better as prevention than once you already feel sick. The leaflet says how long before departure.
- Your hay-fever tablet will not help. Modern "non-drowsy" antihistamines such as cetirizine, loratadine and fexofenadine do not work against motion sickness.
We do not give doses; follow the pack or the pharmacist.
Drowsiness, and who should be careful
The CDC says the most common side effect of these medicines is drowsiness, along with a dry mouth and dry eyes. That has practical consequences in Thailand. Do not ride a scooter or drive a car after taking a sedating tablet, for example after the ferry to Koh Phangan or the van to Pai, and avoid alcohol, which the CDC says should be avoided anyway when you are prone to motion sickness.
Some people need advice before taking anything. The CDC says scopolamine should not be used by people with glaucoma or at risk of urinary retention, and that a patch must never be cut. If you are pregnant, take other medicines, or have a long-term condition, ask a pharmacist or a doctor first and show them what you already take.
Children and travel sickness
Children of primary-school age are the most likely to be sick on a boat or a winding road. The CDC advises caution with medicine for children: scopolamine should be avoided in children, and over-sedating young children with antihistamines "can be life-threatening". The NHS says dissolvable tablets exist for children, and that a pharmacist can recommend the best treatment for your child. Never give a child an adult's tablet.
Non-drug tricks often work better with children. The NHS suggests distracting them with talking, music or songs, and breaking up long journeys with fresh air and a drink of water. Our guide to Thailand with kids has more on planning family transport.
Choosing your seat in vans, buses and boats
In a car or minivan, the NHS advice is to sit at the front and look straight ahead at a fixed point. Thailand drives on the left, so the front passenger seat is on the left. The CDC also tells travelers to avoid overcrowded, overloaded and top-heavy buses and minivans, which sway more and are less safe; our page on minivans in Thailand covers booking and safety, and on long routes a night train is the smoothest ride of all.
On a boat, the NHS says sit in the middle, and the CDC says avoid the bow, the front part that rises and drops the most. On small, fast boats our speedboat guide goes further and recommends sitting as far back as you can. Wherever you sit, keep your eyes on the horizon, get fresh air, and avoid looking at the waves rushing past.
Monsoon swell: picking the day and the boat
The sea is roughest in the monsoon. On the Andaman coast (Phuket, Krabi, Koh Lanta) the southwest monsoon brings rain and swell from about mid-May to mid-October, while the Gulf islands (Koh Samui, Koh Phangan, Koh Tao) get their heaviest rain around November. Our guide to the best time for the Thai islands explains the two seasons.
If you are prone to seasickness, a bigger, slower ferry is usually a gentler ride than a small speedboat, and on a rough day it is worth waiting for calmer weather if your plans allow. Our overview of ferries in Thailand compares the boat types and explains cancellations in bad weather.
Surviving the road to Pai
The road from Chiang Mai to Pai is famous for its hundreds of bends, and travel sickness in the vans is very common. Our Chiang Mai to Pai guide covers the vans, the stops and the alternatives, including the small daily flight that some travelers choose precisely to avoid the road.
If you drive or ride yourself, steady driving on the curves helps passengers as much as any tablet. Our sister site's guide to mountain roads and hairpin bends explains how to drive them safely.
Eat light before the Pai van. The NHS advises against heavy meals, spicy food and alcohol shortly before travel, which in northern Thailand rules out the khao soi right before you board.
Ginger, wristbands and other remedies
Some people find ginger helps, and the NHS suggests trying it as tablets, biscuits or tea. The CDC calls the evidence for ginger weak and contradictory. Acupressure wristbands are sold widely; the NHS says they do not work for everyone, and the CDC says that in laboratory trials they worked no better than a placebo. Neither does harm, so use them if they help you, but do not rely on them for a rough crossing.
Motion sickness should ease soon after the movement stops. If dizziness, vomiting or headache continue on solid ground, come with a fever, or you cannot keep fluids down in the heat, see a doctor, because something else may be the cause. Our guide to hospitals in Thailand explains where to go.
Frequently asked questions
Can I buy seasickness tablets in Thailand?
Yes. Pharmacies across Thailand sell motion-sickness tablets. Ask the pharmacist which suits you or your child, and take it before the trip, as the leaflet says. Buy them the day before an early boat rather than hoping to find a pharmacy at the pier.
Where should I sit on a boat to avoid seasickness?
Away from the bow. The NHS advises the middle of a boat and the CDC says avoid the front. On small speedboats, the seats toward the back move least. Look at the horizon, get fresh air and do not use your phone.
Do non-drowsy antihistamines work for motion sickness?
No. The CDC says newer allergy tablets such as cetirizine, loratadine and fexofenadine are not effective against motion sickness. The medicines that work are older, sedating antihistamines and scopolamine, so ask a pharmacist and expect some drowsiness.
Is there a way to avoid the winding road to Pai?
Partly. A small airline has scheduled one daily Chiang Mai-Pai flight in October 2026, but seats are few. Otherwise, sit at the front of the van, eat lightly, take any tablet in advance and ask for a stop if you feel ill.
Sources
- CDC Yellow Book – Motion sickness (23 April 2025) (checked October 2026)
- NHS – Motion sickness (reviewed 19 June 2023) (checked October 2026)
- CDC – Travelers' health: Thailand (checked October 2026)