Kwells vs Avomine: two UK travel tablets on very different clocks
Short answer: two different drugs on two very different clocks. Kwells is hyoscine hydrobromide 300 micrograms, an anticholinergic. Its label says to take it up to 30 minutes before the journey starts, or at the onset of nausea, with a repeat every 6 hours if required. Avomine is promethazine teoclate 25 mg, a long-acting sedating antihistamine. For a long journey its label puts one dose at bedtime the night before; for a short one, 1 to 2 hours ahead. Both can cause drowsiness, and Avomine's label tells first-time users not to drive for the first few days. Which one, if either, suits you is a question for a pharmacist, and the pack you are holding is the final word.
Key facts
- Kwells is hyoscine hydrobromide 300 micrograms, an anticholinergic, while Avomine is promethazine teoclate 25 mg, a sedating antihistamine, so they are different drugs.
- The Kwells label says to take it up to 30 minutes before the start of the journey, or at the onset of nausea, and allows a repeat every 6 hours if required.
- Per the NHS, the usual promethazine dose for preventing travel sickness is taken the night before the journey, and some products need only be taken 1 to 2 hours before a short one.
- The Kwells label lists drowsiness, dizziness, sedation and somnolence as commonly reported, and says not to drive or operate machinery if affected.
- Both are UK pharmacy medicines sold without a prescription: Kwells by Dexcel Pharma, and Avomine by Manx Healthcare.
Kwells and Avomine are both sold from UK pharmacies for travel sickness, and their labels could hardly be further apart. One is an anticholinergic whose label allows a dose up to half an hour before the journey, or once nausea starts. The other is a long-acting antihistamine whose label puts the dose for a long journey at bedtime the night before.
This page sets out the label facts for both: the active ingredient, the timing each label gives, the repeat interval, the ages and the drowsiness wording. It does not tell you which to take. That is a question for a pharmacist, and the pack in your hand is what you follow.
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Kwells vs Avomine, label by label
| Feature | Kwells | Avomine |
|---|---|---|
| Active ingredient | Hyoscine hydrobromide 300 micrograms | Promethazine teoclate 25 mg |
| Drug family | Anticholinergic | Sedating antihistamine (phenothiazine) |
| Label timing | Up to 30 minutes before the journey, or at the onset of nausea | Bedtime the night before a long journey; 1 to 2 hours before a short one |
| Repeat interval | Every 6 hours if required, with a 24-hour maximum | Once each evening; a second dose within 24 hours is often unnecessary |
| After sickness starts | Label allows a dose at the onset of nausea | Label sets out a schedule for sickness already underway |
| Drowsiness and driving | Drowsiness commonly reported; do not drive if affected | No driving for the first few days for first-time users |
| Youngest age on the label | Over 10 (300 microgram tablet) | 5, at reduced amounts; never under 2 |
| Where it is sold | UK pharmacies, no prescription needed | UK pharmacies, no prescription needed |
Two drugs on two different clocks
Kwells contains hyoscine hydrobromide 300 micrograms, an anticholinergic. Its label says to take a tablet up to 30 minutes before the start of the journey, or at the onset of nausea, and the tablets can be sucked, chewed or swallowed. Repeats run 6 hours apart if required, with a stated maximum in 24 hours, and the 300 microgram tablet lists doses for adults and children over 10.
Avomine contains promethazine teoclate 25 mg, a long-acting sedating antihistamine from the phenothiazine family. For a long journey, its label puts one tablet at bedtime the night before setting out, and the effect lasts long enough that a second dose within 24 hours is often unnecessary. For a short journey, the label gives one tablet 1 to 2 hours before travelling, or as soon after as possible. Unusually, it also sets out a schedule for sickness that has already started, and it is not for use beyond 7 days without medical advice.
Drowsiness, driving and the age line
Neither tablet is non-drowsy. The Kwells label lists drowsiness, dizziness, sedation and somnolence as commonly reported, along with dry mouth and blurred vision, and says not to drive or operate machinery if affected. Alcohol may strengthen its sedative effect. Avomine's label is stricter for a first-time user: no driving or operating machinery for the first few days, until you are sure it does not cause disorientation, confusion or dizziness. Alcohol is to be avoided while taking it.
The age lines differ too. The Kwells 300 microgram tablet carries doses for adults and children over 10. Avomine tablets carry reduced amounts from age 5, are unsuitable from 2 to 5, and must never be given to a child under 2. For any child, the product and the amount are a pharmacist or GP decision.
What the caution lists add
The Kwells label rules it out with glaucoma, prostatic enlargement, paralytic ileus, pyloric stenosis or myasthenia gravis. Avomine's label rules it out within 14 days of a monoamine oxidase inhibitor (MAOI), urges caution in asthma and other chest conditions, and adds a line worth knowing before a sunny trip: photosensitive skin reactions are possible, so strong sunlight should be avoided while taking it.
Pregnancy, breastfeeding, older age and other medicines change the answer for both tablets, and hyoscine and promethazine each add to other sedating or anticholinergic medicines. A pharmacist weighs all of this against your journey, so bring the pack and the list of what else you take.
When to use which
From the labels, Kwells fits a journey that is half an hour away, or nausea that has already started, with repeats 6 hours apart. Avomine's night-before dose is written for a long journey that starts early, and its long action is why a second dose within the day is often unnecessary. Glaucoma rules out Kwells, recent MAOI use rules out Avomine, and both can make you drowsy, which matters if you drive at the other end. None of that is a recommendation. Age, other medicines and health history change the answer, so put the actual question to a pharmacist or GP and follow the pack.
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Frequently asked questions
Which is better for a ferry crossing, Kwells or Avomine?
Neither label ranks itself against the other, so the difference is the clock. For a long crossing that starts early, Avomine's label puts one dose at bedtime the night before; for a short one, 1 to 2 hours ahead. The Kwells label puts a dose up to 30 minutes before the start of the journey, or at the onset of nausea, with repeats 6 hours apart. Both can cause drowsiness. A pharmacist can match either label to your crossing, your health and your other medicines.
Can you take Kwells and Avomine together?
Do not combine them without asking a pharmacist or GP first. Both can sedate, and Avomine's label says other anticholinergics, which include hyoscine, add to its effects. If one tablet is not suiting you, a pharmacist can look at your doses, your other medicines and your journey before suggesting a change.
Which makes you less drowsy, Kwells or Avomine?
Neither is non-drowsy, and the labels do not rank them. The Kwells label lists drowsiness, dizziness, sedation and somnolence as commonly reported and says not to drive or operate machinery if affected. Avomine's label tells first-time users not to drive or operate machinery for the first few days, until they are sure it does not cause disorientation, confusion or dizziness. Reactions vary from person to person, so ask a pharmacist if you need to stay alert at the destination.
Kwells versus Avomine is a question about the clock: up to half an hour before the journey, or the night before it. Match the label timing to the trip, let a pharmacist check the fit against your health and your other medicines, and read the pack you are holding.
Related comparisons
- Kwells: the full label facts
- Avomine: the full label facts
- Hyoscine hydrobromide, the ingredient behind Kwells
- Promethazine, the ingredient behind Avomine
- All motion sickness comparisons
Where these facts come from
- Kwells 300 microgram tablets, Summary of Product Characteristics (emc)
- NHS, How and when to take promethazine
- Avomine 25mg tablets, NHS Dictionary of medicines and devices (dm+d)
Active ingredients and label warnings were re-read at these sources in October 2026. Labels and formulations change, and they differ by country, so the box in your hand is the final word.
This page is informational and not a substitute for professional medical advice; talk to your doctor or pharmacist and follow the product label. Kwells, Avomine and other product and brand names are trademarks of their respective owners; Dizzout is not affiliated with or endorsed by them.