Xonvea - Morning Sickness Treatment
- UK’s only licensed pregnancy sickness medication
- 10mg/10mg tablets (doxylamine, pyridoxine)
- Effective at treating nausea and vomiting during pregnancy
- Take two tablets at bedtime, increasing up to four tablets throughout the day, if needed
20 Tablets
40 Tablets
What is Xonvea?
Xonvea is a prescription drug that treats pregnancy sickness (nausea and vomiting), which affects up to 80% of pregnant people.
It’s typically prescribed for pregnant people over 18 who haven’t found other ways of treating their symptoms effectively.
How does Xonvea work?
Xonvea has two active ingredients, doxylamine, which is an antihistamine, and pyridoxine, which is a form of vitamin B6.
Doxylamine prevents the effects of chemicals produced by the body (called histamines) which contribute to feelings of nausea.
Pyridoxine (vitamin B6) plays an important role in brain health and metabolic health. It’s known to reduce symptoms of nausea, but experts don’t fully understand how and why it has this specific effect.
How effective is Xonvea?
For most people, Xonvea is both effective and well-tolerated in terms of side effects.
A 2025 survey of 749 people found that 83% of people who had been prescribed Xonvea found it to be effective at reducing pregnancy sickness.
And a clinical trial conducted by experts in 2010 found that Xonvea showed significantly better improvements in symptoms of pregnancy sickness than a placebo.
Is Xonvea safe in pregnancy?
Yes, Xonvea is considered safe during pregnancy.
It’s been licensed for use in the UK because a large amount of data on pregnant people has indicated no increased risk of birth defects, according to the NHS.
If you’re having pregnancy sickness and are interested in taking Xonvea, you’ll need to talk to a prescriber, who can help you assess if Xonvea is suitable for you.
Can you get Xonvea tablets on the NHS?
Xonvea is currently the only treatment licensed specifically for pregnancy sickness in the UK.
However, whether you can get Xonvea on the NHS depends on where you live, because different local healthcare authorities have different prescribing guidelines.
In most areas, Xonvea isn’t routinely available and needs to be prescribed by a specialist on a case-by-case basis.
In some places, prescribers will only recommend Xonvea if your nausea and vomiting during pregnancy are severe and are causing dehydration or unwanted weight loss (a condition called hyperemesis gravidarum).
In these cases, prescribers will usually require you to have tried at least one other medication for your symptoms that hasn’t worked.
Xonvea side effects
Common side effects of Xonvea include:
- dizziness
- drowsiness
- dry mouth
- fatigue
Less common side effects include:
- anxiety
- chest discomfort
- constipation
- diarrhoea
- disorientation
- dyspnoea
- gastrointestinal (digestive) discomfort
- headaches
- hyperhidrosis (excessive sweating)
- irritability
- heart palpatations
- paraesthesia (strange sensations in the skin)
- sleep disorders
- tachycardia (fast heartbeat)
- urinary disorders
- vertigo
- vision disorders
How to take Xonvea tablets
Xonvea should be taken with a glass of water on an empty stomach.
The recommended dosage for Xonvea is:
1. Starting dose of two 10/10mg tablets at bedtime.
2. If this dose doesn’t relieve your symptoms after two days, you can take an extra one 10/10mg tablet in the morning alongside the two bedtime tablets from day three onwards.
3. After day three, if symptoms persist, take one 10/10mg tablet in the morning, one mid-afternoon, and two at bedtime.
4. The maximum dose is four tablets a day.
When to avoid Xonvea tablets
Xonvea can cause drowsiness, so you should excise caution if you are driving or operating heavy machinery. Our advice is to see how you feel after 24-48 hours and then decide whether you feel safe enough to drive or not. If in doubt, don’t drive or operate machinery.
You should also tell your doctor if you have:
- allergies to doxylamine or pyridoxine
- breathing problems like asthma
- eye problems like glaucoma
- stomach or urinary (bladder) issues
Xonvea can also cause interaction with certain medications, including:
- opoid painkillers
- sleep medications
- anxiety medications
- other antihistamines
Alternatives to Xonvea
Before you try Xonvea, or if Xonvea is not available on prescription in your area, your doctor may recommend:
- cyclizine (oral or injection)
- prochlorperazine
- chlorpromazine
- promethazine
Frequently asked questions about Xonvea tablets
Is Xonvea the same as cyclizine?
No, cyclizine is a different medication to Xonvea, although they are similar. Both are antihistamine medicines that treat nausea. But unlike Xonvea, cyclizine does not contain pyridoxine (vitamin B6).
Can Xonvea cause a miscarriage?
There is currently no evidence that Xonvea can cause miscarriage, although miscarriage is possible in any pregnancy.
What is the best time to take Xonvea?
If you’re taking the starting dose of Xonvea, you should take it at bedtime, on an empty stomach, with a glass of water.
Sources
-
Nausea and Vomiting in Pregnancy (NVP) - MotherToBaby. (2024). National Library of Medicine. [Accessed 24 February 2026].
-
Establishing the Cost and Impact of Xonvea for NVP. (2025). Pregnancy Sickness Support. [Accessed 24 February 2026].
-
Effectiveness of delayed-release doxylamine and pyridoxine for nausea and vomiting of pregnancy: a randomized placebo controlled trial. (2010). PubMed. [Accessed 24 February 2026].
-
Information and Advice on Nausea and Vomiting in Pregnancy. NHS Trust. [Accessed 24 February 2026].
